January 3, 2017

Website wishes – A Very Happy New Year 2017

Filed under: NIL - All Posts — myreaders @ 3:10 pm

I wish a Happy New Year – 2017 to all the visitors to my website, URL

The web count 3,30,570 tells that the website has earned the confidence of about 50,000 new and returning visitors during the year 2016.

Review of Year ending 2016 : The year was nice, provided all opportunity but I was unable to cash on. Except for few routine posts on my Blog and Social sites, I could not complete the most demanding and intensive work of rewriting the pages on ‘Image processing & Computer vision’ of my website. I want to quickly complete it along with other pressing need.

Plan for the Year 2017 :  Continuing with long term (Year 2016-20) task titled ‘Launch Mechanics – Model & Simulation Software (LM-MSS)’ is progressing as per schedule. This software is about satellite launch in LEO, GEO and Interplanetary mission.

I once again wish all a very happy and prosperous New Year – 2017.

By R C Chakraborty,

June 7, 2016

Problem Solving Methodology in Real World Situation

Filed under: 09. Projects & Proposals, NIL - All Posts — myreaders @ 9:23 am

Title :    Problem   Solving   Methodology    in    Real    World    Situation

R  C  Chakraborty,

Article   in   tutorial   form   for   students   working  on   ‘Real   World   Problem   Solving   Project’.

Your   problem   belongs   to   a   Real   World   Situation.

Start   with   a   few   things   you   may   or   may   not   know,   then   move    on  to  problem  solving    methodology.

1.   Problems  are  of   two   types

  • Analytical  problems  like  ‘computation  of  the square’  can  be  solved  through  the use  of  deterministic  procedure  and  the   success  is  guaranteed.
  • Real world problems do not offer straight forward  solutions. The most real world problems  can  be  solved  only  by  searching  for  a  solution.

Here  after   the  word   problem  addresses  only  real  world  problem.

2.   Defining  few  terms  

  • Problem  is  defined  by  its  elements   and  their  relations.
  • State  is  a  representation  of  elements  at  a  given  instant.
  •  Descriptors  tell  how  to  select  elements ?   At  each  instant  elements  have     specific  descriptors  and  relations.
  • Initial  state    is     start point.
  • Final  state      is     goal state.
  • State  change  means  moving  one  state  to  another  state.
  • Successor  function  is  a  description  of  possible  actions  for  state  change.
  • Actions   are   a  set  of  operators.
  • State  space  is  the set of all states reachable from the initial state that  forms a graph  (or map).
  • Structures  of  State  space   are   graphs   and   trees.
  • Graph  is  a  non-hierarchical  structure  has several paths  to  a  given node.   A graph  consists  of  a  set  of nodes  (vertices)  and  a  set  of edges (arcs).  The  nodes are  states  and  the edges  between  nodes  are  actions.  The edges establish  relations  (connections)  between  the   nodes.
  • Tree  is a  hierarchical  structure  in  a  graphical  form.  A   tree  has  one  and  only one  path  from  any  point  to  any  other  point.
  • Path  :  In  state  space,  a  path  is  a  sequence  of  states  connected  by  a  sequence  of   actions.

3.   Problem  solving  is  a  process  of  generating solutions  from  observed data.  The  data  consists  a  set  of  goals ,  a  set  of  objects ,   a  set  of  operators.  In  problem  solving it  is not  always  possible  to  go  directly  from  data  to  solution  called  direct methods. Instead,   problem   solving   often   need   to   use  indirect   or   model-based   methods.

4.   Problem  definition  :  A  problem  is  defined  precisely,  by  its elements  and  the relations  among  elements,  by  finding  the  input  and  the  final  situations  for  an acceptable  solution.  The  elements  and  relations  could  initially be  ill-defined  and evolve   better   during   problem   solving.

5.   Problem   space   is   an   abstract   space   called   state  space.

  • Problem  space   encompasses   all   valid  states  generated  by  the  application  of operators   on   any   combination  of  objects.
  • Problem  space   may   contain  one  or  more  solutions.
  • Solutions  are   combination  of  operators  and  objects  that  achieve  the  goal.

6.   Search   refers   to   the  search   for  a  solution  in  a  problem  space.  The   search  proceeds   with   different   types   of   search   strategies.

7.   Building   system   to   solve   problem  :  you  need  to   do   the   following.

  • Define   the   problem   precisely  (as  mentioned  above).
  • Analyze   the  problem,  means  find  few  important  features  that  may  have  impact   on   possible   techniques   for   solving   the   problem.
  • Isolate   and   represent   task   knowledge   necessary   to   solve   the   problem.
  • Choose   best   problem   solving   technique(s)   and   apply   to   solve   the  problem.

 8.   Formal   description   of   a   problem  :   you   need   to   do   following.

  • Define  problem  space  called  state  space  that  contains  possible  configurations    of   the   relevant   objects.
  • Specify  one   or   more  states  from  which  the  problem-solving  process  may start.   These   states   are    called   initial  states.
  • Specify  one  or  more  states  that   would  be  acceptable  solution  to  the  problem.   These   states   are   called   goal   states.
  • Specify  a  set   of   rules   that   describe   the   actions  (operators)   available.

9.   Problem  solving  model :  Most   if   not   all    real-world  problems   do   not  offer  any   direct   solution.   The   real-world   problems   are   solved   algorithmically.

  • Algorithmic  solution  means  looking  for  a  finite set  of  unambiguous  instructions such  that  given  a  set   of  initial  conditions,  the  instructions  can  be  performed  in  a   prescribed  sequence  to  achieve  a  certain  recognizable  set  of end  conditions   called   goals   (solutions).
  • Instruction  sets   comprise  rules   combined   with  a  strategy. The   instructions  sets  are  steps  that  pass  through  the  problem  space  until  a  path   from  an initial  state  to  a  goal  state  is  found.  This  methodology  is  known  as  search  process   and   the   algorithm   is   known   as   problem   solving   model.

10.  Summary   of   problem   description   &   solving

  • Problem  consists  the  description  of current state  and  the actions  that  can  transform   one   state   into   another  state  to   reach   the  goal  state.
  • State  space   describes   everything   that   is   needed  to  solve  a  problem.
  • Operators  are  to  change  state,  do  actions  that  can  transform  one  state  into another. The  operators  include  the preconditions  and  the   instructions. The preconditions  provide  partial  description  of  the states  that  must  be  true  to perform   the   actions.  The  instructions   tell  on  how  to  create  next  state.
  • Problem  solving   is   finding   an  ordered sequence  of  operators  that  transform  the  current  (start)  state   into   next   state   and   finally   goal   state.

11.  Mathematical   formulations 

Follow  the  notations  and   the  representations  for  set,  relation,  function,  domain,  range,  restrictions,  mapping,   equation   and   many   more.

  • Set  is  a  collection  of  distinct  things  or  items  or  objects,  or  numbers  etc,  that have  common  property  among  them.  Examples :   (a)   Collection  of  items you wear  like  :  shoes,  socks,  hat,  shirt;    (b)   Collection of  types  of  fingers  as  :  thumb,  index, middle,  ring,  pinky;   (c)   Collection of  odd  numbers  as  :  1 , 3 , 5 , 7 , 9 , 11 , 13 ;   The  individual  item  such  as  shoes,  socks,  middle,  ring,  3 ,  5 ,  11 are  called   element   or   member   of   the   respective   set   or   collection   or   group.
  • Set  representation  is  a  list of  elements  separated  by  a comma,  and  then  put  the  whole  thing   within  curly  brackets   around.  Examples :  (a)  Set  of  items  you  wear  :  {shoes,  socks,  hat,  shirt}.  (b)  Set of fingers : {thumb,  index, middle,   ring,  pinky} .  (c)  Set  of  odd  numbers  :  {1,  3,  5,  7,  9,  11,  13} .
  • Relation   is   a   set   of  ordered  pair  of  the  form  (x, y) .  Example :  A  set  { (1 , a),  (1 , b),   (2,b),   (3,c),   (3, a),   (4,a) }   is   a   relation.
  • Function  relates   an  input  to  an  output. A  function  has  three  parts :  (a)  input,  (b) relation-ship,   (c)  output.  Example :  f(x)  =  x2   where  f  is name  of   the  function  used. The  input  is x  is  that  goes  into  the function  is  put  inside  parentheses () ;   The  relationship  is  what  function  does  to  the  input  is  ‘squaring’ ;   The   output  is  x2.  Example :  If  input  is  4  then  function  is  written  as  f(4)  =  16   which   means    is   some   way  related  to  16   which   is  expressed as   4 → 16   that   tells   4   is   mapped   into   16 .
  • Function  is  a  relation (a  set  of  ordered  pairs)  usually  named  by  lower-case  letters   such  as  f ,  g ,  h.   Example :  f  =  { (-3 , 9) ,  (0 , 0) ,  (3 , 9) } ;    g  =  {(4 , -2),  (4 , 2) }
  • Function   has   a   rule   in   which  no  two  ordered  pair  have  same  x-value  but  may  have  same  or  different  y-value.  In  the  above  example  f  is  a   function   but g  is  not  a   function.
  • Domain,  Co-domain  &  Range  of  a  function  f =  {(X , Y)} . These  are  names  used  in  defining  function.   Definitions :   (a)  Domain  is  set  X  of  elements  that  can  go into  the  function;   (b)   Co-domain  is  set  of  elements  what may possibly  come  out of function.;   (c)  Range  is set  Y  of  elements that  actually comes  out  of  a function.  Example :  If  a  function  f  =  {(a , A), (b , B), (d , D)}   then   (a)  domain  of  the  function  is  {a , b , d }  ;    (b)   co-domain  of  the  function  is  {A , B , C ,  D ,  E } ;(c)  range  of  the  function  is  {A , B , D } .
  • Function  and   mapping  :  A  function   may   be   viewed  as  a  mapping  or  a  pairing  of  elements   of   one  set  with  elements  of  second  set  such  that  each  element  of  the  first  set  (called  domain  is  paired  with  exactly  one  element  of  the  second   set  (called   co-domain).  Example  :  If  a  function f,  maps  set {a , b , d } into   set {A , B , C , D , E}   such   that   a → A   (read  ‘a  is  mapped  into  A‘) ,    b → B , d → D  then   the   domain   is  {a , b , d}   and   the   co-domain   is  {A , B , C , D}.  Note  that   (a)  the  element  of  the  co-domain  which  corresponds  to  an  element of  the  domain  is  called   the   image   of   that   element.  For  example,  element  a  of   domain   is   paired with   element    in   co-domain,  then  A  is  called  the  image   of  a ;   (b)  The  set   of   image   points {A , B , D}   is   called   the  range.  Thus,   range   is   a   subset   of   the   co-domain.
  • Onto  mappings :   Set  A  is  mapped  onto  set  B   if  each  element  of  set B  is  image  of   an   element  of   a  set A.  Thus,   every  function  maps  its  domain  onto  its   range.
  • Describing  function   by  an   equation : The  rule  by  which  each  x-value  gets  paired  with  the  corresponding  y-value  may  be  specified  by  an  equation. Example :   A   function   described  by   equation  y  =  x + 1   requires   that   for   any  choice   of  x  in  the  domain,   the   corresponding   range   value   is  x + 1.    Thus,   2 → 3 ,   3 → 4 ,    4 → 5   is   the   function   description

12.  Example  of   a  Real   World   Problem  :  

      A   game   of   8–Puzzle .    Solve   the   problem   algorithmically.

  • State space    :    configuration  of  8 – tiles  on  the  board.
  • Initial state    :    any configuration
  • Goal state      :    tiles in a specific order
  • Action            :    ‘blank moves’
  • Condition      :    the  move  is  within  the  board
  • Rule              :    blank  moves  Left,  Right,  Up,  Dn
  • Solution        :    optimal sequence of operators

Conclusion  : 

You   have   learned   a   methodology   to   solve    Real   World   Problems.   Apply   this methodology    and    solve    your   specific    ‘Real   world   problem’.

Tags :   Real World  Situation,  Problem definition,  Problem  solving,  Problem  space, Search,  Building system  to  solve  problem,  Formal  description  of  a  problem,  Problem solving  model,  Mathematical   formulations,  Example  of  real-world  problem.

Related  reading  :

  1. Teaching   Mathematical   Modelling   in   Singapore   Schools
  2. How   to   Convert   a   Basic   Word   Problem   into   an   Equation
  3. Problem   Solving,   Search   and   Control   Strategies,

May 27, 2016

HAPPY DAY For My Website

Filed under: NIL - All Posts — myreaders @ 4:46 pm

My website  is  an  educational  website,  provides  free  access  to  any  one.  There  is  no  pop-up Ads  of  any  kind.  The  website  is  an  individual’s endeavor.  All  posts  are  my  own  creations,  includes  several  pdf  files  consisting thousands of  pages.  I  am  very  happy  today, the  May 27, 2016.

The  Website  Counter,  Showing   Visitor’s   Count,   Crossed  3,00,000.

I sincerely  thank  to  all  visitors.

RC Chakraborty

Learn Orbital Mechanics – motion of earth, sun, moon & satellites

Filed under: 08. Orbit & Space Tech., NIL - All Posts — myreaders @ 7:19 am

Title  :  Learn  Orbital  Mechanics – motion of earth, sun, moon & satellites

Ref URL  :

Access  :  Free,  no  registration  required.

Description  : Topics organized into 8 sections include tutorials & software  driven computations – Introduction to Orbital mechanics, Astronomical time standards & conversions, Positional astronomy – earth orbit around sun, Position of sun on celestial sphere, Position of earth on celestial sphere, Satellites orbit elements – ephemeris, keplerian elements, state vectors, Satellites motion around earth – orbital & positional parameters, Satellite pass for earth Station – prediction of ground trace. (Total 400 pages in 8 pdf files include text, graphics, examples, problems & OM-MSS software  driven test results).

Objectives  :  Free online self explanatory learning resources & teaching materials.

Who Should read  :  Beginners,  senior students,  professionals  and  researchers.

Author : RC Chakraborty, , Former Visiting Professor at JUET.

Conditions of Use :  Creative Commons Attribution-Noncommercial-No Derivative Works

4.0 International [Ref. ]

Update  on  Dec. 20, 2015

Tags : OM-MSS software, Orbital mechanics, Astronomical time, Positional astronomy, Sun position on celestial sphere, Earth position on celestial sphere, Earth motion around sun, Satellites orbit elements, Satellites motion around earth, Satellite pass ground trace for earth Station.

Learning Soft Computing – university course lecture notes

Filed under: 03. Soft Computing, NIL - All Posts — myreaders @ 7:13 am

Title  :  Learning  Soft  Computing –  university  course  lecture  notes

Ref  URL  :

Access :  Free,  no  registration  required.

Description  :  Topics organized into 9 sections following academic curriculum – Introduction to soft computing, Fundamentals of neural network, Back propagation network, Associative memory, Adaptive resonance theory, Fuzzy set theory, Fuzzy systems, Fundamentals of genetic algorithms, Hybrid systems. (Total 400 pages in 9 pdf files include text, graphics, examples, problems & solutions).

Objectives  :  Free online self explanatory full course learning resources & teaching materials.

Who Should read  :  Beginners, senior students, professionals and researchers.

Author : RC Chakraborty, ,  Former Visiting Professor at JUET.

Conditions of Use :  Creative Commons Attribution-Noncommercial-No Derivative Works 2.5 [Ref. ]

Update on Dec. 20, 2015

Tags : Soft computing, Neural network, Back propagation network, Associative memory, Adaptive resonance theory, Fuzzy set theory, Fuzzy systems, Genetic algorithms, Hybrid systems.

May 21, 2016

Learning Artificial Intelligence – university course lecture notes

Filed under: 02 Artificial Intelligence, NIL - All Posts — myreaders @ 2:26 pm

Title :  Learning Artificial Intelligence – university course lecture notes

Ref  URL :

Access :  Free, no registration required.

Description :  Topics organized into 11 sections following academic curriculum – Introduction to AI, Problem Solving, Search & Control Strategies, Knowledge representation – logic & rules, Reasoning system, Game playing, Learning system, Expert system, Neural network, Genetic algorithm, Natural language processing, and Common sense. (Total 600 pages in 11 pdf files include text, graphics, examples, problems & solutions).

Objectives :  Free online self explanatory full course learning resources & teaching materials.

Who Should read :  Beginners, senior students, professionals and researchers.

Author :  RC Chakraborty, , Former Visiting Professor at JUET.

Conditions of Use:  Creative Commons Attribution-Noncommercial-No Derivative Works

2.5 [Ref. ]

Update on Dec. 20, 2015

Tags :  Artificial intelligence, Problem solving, Knowledge representation, Reasoning system, Game playing, Learning system, Expert system, Neural network, Genetic algorithm, Natural language processing, Common sense.

December 31, 2015

Happy New Year 2016 Messages –

Filed under: NIL - All Posts — myreaders @ 4:29 pm

Happy   New  Year  2016  Messages  :   I  convey  my  best  wishes,  love  &  regards  to  my  near  and  dear  ones, and  all  the visitors  to  my  website  URL .

Review  of  Year  Ending  2015  :   Has  been  nice,   enjoying   and   productive  in  a  sense   that  I  completed  the development  of  a  long  cherished   Software   Titled   ‘Orbital   Mechanics  Model  &  Simulation  Software  (OM-MSS)’.   The  same  is  uploaded   on   my  Website  Page  URL   This   Software  is  for   Computing  Astronomical  Time Standards  and   Time   Conversions,   Positional   Astronomy – Earth  Orbit   around  Sun,   Position  of  Sun  on  Celestial  Sphere,   Position   of   Earth   on   Celestial   Sphere,    Satellites   Orbit  Elements  –  Ephemeris,   Keplerian Elements,  State  Vectors,   Satellites  Motion  around  Earth  –  Orbital   &  Positional  Parameters,   Satellite  Pass   for  Earth  Stn  –  Prediction  of   Ground   Trace.

Plan  for  Year  New  2016  :   Developing  a  new  software ,  Titled   ‘Launch  Mechanics  Model  &  Simulation Software  (LM-MSS)’   is  about   Satellite   launch  in  LEO,  GEO   and  Interplanetary  mission.   This   is  likely  to complete   in  next   four   Years.

I  once  again  wish  a  very  happy  and  prosperous  New  Year   for   all  being ,  and  the  visitors  to  my  website.

From R C  Chakraborty,  Former  Dir. DTRL & ISSA, DRDO, Delhi  &  Visiting  Professor,  JUET,  Guna,

July 17, 2015

Satellite Pass for Earth Station – Prediction of Ground Trace Coordinates & more

   Satellite  Pass  for  Earth  Stn  –  Prediction  of  Ground  Trace  Coordinates   &  more.

by  R C  Chakraborty,   July 17,  2015,   Pages   268 – 390.

(This   is   Sec. 7,    pp  268 – 390,   of   Orbital   Mechanics  –  Model   &   Simulation   Software  (OM-MSS),   Sec.  1  to 10,   pp  1  –  402.)

Satellites,  look  like  slow-moving  Stars,  are  most  visible  when  they  are  in  Sunlight  while  the  viewer  is  in  darkness.

A  typical  Satellite  in  low  Earth  orbit  (LEO)   circles  the  Earth  about  16  times  each  day.

The  Orbital  Velocity  of  a  LEO  satellite  is  about  7500  meters/sec.

The  Orbital  Velocity  of  a  Geo-stationary  satellite  is  about  3007  meters/sec.

The  Moon,  the  only  natural  satellite  of  earth  has  orbital  velocity  about  1003  meters/sec.

Satellite  Pass  for  Earth  Stn,   is  Computed   for  following  six  satellites  :   LANDSAT 8,   SPOT 6,   CARTOSAT-2B,   ISS (ZARYA),   GSAT-14,   and   MOON.

The  ‘Satellites  Pass’   goes  through  a  Time_Step  of  2 minutes  (120 sec).   For  Moon  the  Time_Step  is  of  1 hr  (3600 sec).

The  input  is  respective  Satellite’s  NASA/NORAD  ‘Two-Line Elements’  (TLE).

The  Output  is   Predictions   of   instantaneous   Ground  trace  Coordinates,   look  angles  &  more  at  each  Time_Step   on   computer   screen   in   a   Table   form    where

respective   columns   indicate  :

Col 1 – Orbit no,                        Col 2 – Node  Ascending  or  Descending,          Col 3 to 6 – Input  time  GMT  D H M S,

Col 7 – True  Anomaly,            Col 8 – Sat  Height  from  earth  surface,             Col 9 – Sat  at  Perigee,  Equator,  or  Apogee,

Col 10 – Sat  Velocity,              Col 11 , 12 – Latitude & Longitude at sub-satellite point on earth surface,

Col 13 – Sat  Slant  Range  from  earth  stn,             Col 14 – Distance  of  sub-satellite  point  from  earth  stn,

Col 15 , 16 – Sat  Pitch  &  Roll  angles,                      Col 17 , 18 – Sat  Elevation  &  Azimuth  angles  at  earth  stn,

Col 19 – Access  to  Sat  through  On  Board  Computer  or  Direct  Line  Of  Sight  based  on  elevation  angle  at  ES,

Col 20 , 21 – Sun  Elevation  &  Azimuth  angles  at  sub-Satellite  point  on  earth  surface,

Col 22 – Data  Acquisition  using  Visible  Band  Camera  or  Night  Vision  Devices  as  per  illumination  over   observed  surface,

Col 23 to 26 – Local  Mean  Time  at  earth  stn,       Col 27, 28 – Sun  Elevation  &  Azimuth  angles  at  earth  stn,

Col 29 – Distance  of  Sub-Sun  point  on  earth  surface  from  earth  stn,

 Col 30 – Line  number .

For   complete   post  (Page  268 – 390)    Move   on   to   Website   URL  :

July 15, 2015

Satellites Motion around Earth : Orbital & Positional Parameters at Epoch

   Satellites   Motion   around    Earth   :   Orbital   &   Positional   Parameters   at   Epoch

by   R C  Chakraborty,   July 15,  2015,   Pages  193  –  267.

(This   is   Sec. 6,    pp  193 – 267,   of   Orbital   Mechanics  –  Model   &   Simulation   Software  (OM-MSS),   Sec.  1  to 10,   pp  1  –  402.)

The   Satellites   Orbit   around   Earth   Counterclockwise   in   the   same   way   as   Earth   orbits   around   Sun.

In  the  previous  section,   the  preliminaries  about  ‘Satellite  Orbit’   followed  by  NASA / NORAD  ‘Two-Line  Elements’ (TLE)   were  presented.   (Ref.

Here  presented  Satellites  Motion  around  Earth  :  Computing  Orbital  &  Positional  parameters,  the  OM-MSS software  utility.   This  utility  is  applied  one-by-one  to  six  satellites,   LANDSAT 8,   SPOT 6,   CARTOSAT-2B,  ISS (ZARYA),   GSAT-14,  &   Moon.   The  Input  is  NASA / NORAD  ‘Two-Line Elements’ (TLE)  Bulletin   of   the respective  satellite.   The  Output  is  corresponding  satellite’s  motion  around  earth,  the  orbital  &  positional parameters.

Satellite  motion  around  Earth  is  represented  by  computing  about  120  orbital  parameters,   put  into   28 groups.   The  number  is  large,   because  some  parameters  are  computed  using  more  than  one  model  equation, that  require  different  inputs.   This  confirms  accuracy  &  validation  of  results  and  understanding  the  different input   considerations.

Satellite  Orbital  &  Positional  parameters  for  computation  purpose  are  put  into  following  groups  :

1.    UT  Year  and  Days  decimal  of  year  :   Convert  into  UT  YY  MM  DD  hh  min  sec  &  Julian day.

2.    Satellite  Orbit  Semi-major  axis  in  km,   Ignoring   and   also  Considering  earth  oblatenes.

3.    Satellite  Mean  motion  in  rev  per  day,   Ignoring   and   also  Considering  earth  oblatenes.

4.    Satellite  Orbit  Time  Period  in minute  at  time_t  Considering  earth  oblatenes.

5.    Satellite  Rate  of  change  of  Right  Ascension  and  Argument  of  Perigee  in  deg  per  day  at  time_t.

6.    Satellite  Mean  anomaly,   Eccentric  anomaly,   True  anomaly  in  deg  at  time_t  considering   earth oblateness.

7.    Satellite  Position  vector [rp, rq]  from  Earth  Center (EC)  to  Satellite  in  PQW  frame,   perifocal  coordinate  system.

8.    Satellite  Position  Range  Vector  from  Earth  Center (EC)  to  Satellite (SAT)  –  finding  Range  Vector [rI,  rJ,  rK,  r]  Components  in  km  in  frame  IJK.

9.    GST  Greenwich  sidereal  time  and  GHA  Greenwich  hour  angle  in  0  to  360  deg,   at  input  at  time_t.

10.  Satellite (SAT)  Orbit  point  direction  :   Finding  Right  Ascension (Alpha)  deg  and  Declination (Delta)  deg  using  angles.

11.  Satellite  Longitude  &  Latitude  in  deg at  time_t ;   (ie  Sub-Sat  point  log  &  lat  on  earth  surface).

12.  Satellite  height  in  km  from  EC  to  Sat  and  from  Earth  surface  to  Sat  at  time_t.

13.  Distance  of  Sub-Sat  point  To  Earth  Stn (ES)  in  km  over  Earth  surface  at  time_t.

14.  Local  sidereal  time (LST)  and  Local  mean  time (LMT)  over  Sub-Sat  point  Longitude  on  earth.

15.  Local  sidereal  time (LST)  and  Local  mean  time (LMT)  over  Earth  stn (ES)  or  Earth  point (EP)  Longitude.

16.  Earth  Stn  Position  Vector  from  Earth  Center (EC)  to  Earth  Stn (ES)  :   Finding  Range  Vector [RI,  RJ,  RK,  R]  Components  in  IJK  frame.

17.  Satellite  Position  Range  Vector  from  Earth  Stn (ES)  to  SAT  :   finding  Range  Vector [rvI,  rvJ,  rvK,  rv]  components  in  km  in  IJK  frame.

18.  Satellite  Position  Range  Vector  from  Earth  Stn (ES)  to  SAT  :   finding  Range  Vector [rvS,  rvE,  rvZ,  rv]  components  in  km  in  SEZ  frame.

19.  Elevation (EL)  and  Azimuth (AZ)  angle  of  Satellite  at  Earth  Observation  point  ES  or  EP.

20.  Satellite  Velocity  meter  per  sec  in  orbit.

21.  Satellite  Velocity  Vector [vX,  vY,  vZ]  in  meter  per  sec  in  orbit  in  frame XYZ.

22.  Satellite  Pitch  and  Roll  angles.

23.  Satellite  State  Vectors  –  Position [ X,  Y,  Z ]  in  km  and  Velocity [ Vx,  Vy,  Vz ]  in  meter  per  sec  at  time_t.

24.  Satellite  Direction  ie  Right Ascension  Alpha  deg  and  declination  Delta  deg  using  sat  position  vector.

25.  Satellite  Angular  momentum  km  sqr  per  sec  :   finding  [Hx,  Hy,  Hz,  H]   using  state  vector  position   and velocity.

26.  Satellite  Orbit  normal  Vector  :   finding  [Wx,  Wy,  Wz,  W] ,  Delta,  Alpha,  using  r_sat_pos  frame  IJK,  i,  RA.

27.  Satellite  Position  Keplerian  elements  computed  using  State  Vector,   at  time  input  UT.

28.  Satellite  Position  State  Vectors,   computed  using  Keplerian  elements  at  time  input  UT.

All  these  Orbital  &  Positional  parameters  are  computed  respectively  for  six  satellites  LANDSAT 8,   SPOT 6,   CARTOSAT 2B,   ISS (ZARYA),   GSAT-14,   &   Moon.

For  complete  post  (Page  193  –  267)   Move  on  to   Website   URL  :

July 14, 2015

Satellites Orbit Elements – Ephemeris, Keplerian elements, State vectors

   Satellites  Orbit  Elements  –  Ephemeris,  Keplerian  elements,  State vectors

by   R C   Chakraborty,   July 14,  2015,   Pages  164 – 192.

(This   is   Sec. 5,    pp  164 – 192,   of   Orbital   Mechanics  –  Model   &   Simulation   Software  (OM-MSS),   Sec.  1  to 10,   pp  1  –  402.)

Satellite  is  an  artificial object,  intentionally  placed  into  orbit.  Thousands  of  Satellites  have  been  launched  into orbit  around  Earth.  A  few  Satellites  called  Space  Probes  have  been  placed  into  orbit  around  Moon,  Mercury,  Venus,  Mars,  Jupiter,  Saturn, etc.  The  Moon  is  the  Earth’s  only  natural  Satellite,  moves  around  Earth  in  the same  kind  of  orbit.

The  Motion  of  a  Satellite  is  a  direct  consequence  of  the  Gravity  of  a  body  (earth),   around  which  the  satellite  travels  without  any  propulsion.    A  satellite  move  around  Earth  is  pulled  in  by  the  gravitational  force (centripetal)  of  the  Earth.    Contrary  to  this  pull,  the  rotating  motion  of  satellite  around  Earth  has  an  associated  force  (centrifugal)  which  pushes  it  away  from  the  Earth.    The  centrifugal  force  equals  the  gravitational  force  and  perfectly  balance  to  maintain  the  satellite  in  its  orbit.

The  Velocity  of  a  Satellite  in  circular  or  elliptical  orbit  depends  on  its  altitude  ‘h’  at  that  point.   Secondly,  the  mass  of  satellite  does  not  appear  in  its  velocity  equations.    Thus  satellite  velocity  in  its  orbit  is  independent  of  its  mass.   Further,  a  satellite  in  elliptical  orbit  moves  faster  when  closer  to  earth  (near  perigee)  and  moves  slower  when  farther  from  earth  (near  apogee).

Preliminaries   about   Satellite   Orbit   :

Earth  Gravity  and  Satellite  Motion,   Velocity  equations,   Attitude  control,   Time  period,  Orbits,  Low  earth  orbit  (LEO),  Medium  earth  orbit  (MEO),   High   earth  orbit  (HEO),   Geosynchronous  orbit  (GSO),   Geostationary  (GEO),   Equatorial  Orbit,   Polar  Orbit,   Sun-synchronous  orbit.    Satellite  Ephemeris  data,   Satellite  Orbit  Keplerian  Element  Set,   Satellite  Orbit  State  Vectors   Set,   Ground  Trace.

Satellite   Ephemeris   data   and   conversion   utilities  of   the   OM-MSS   software   :

Satellite  Ephemeris  is  expressed  either  by  ‘Keplerian  elements’   or   by  ‘State  Vectors’,   that  uniquely  identify  a  specific  orbit.

1.   NASA / NORAD  ‘Two-Line  Elements’  (TLE)  Ephemeris  Data  Set   :    The  Keplerian  elements  are  encoded  as  text  in  different  formats.    The  most  common  format  is  NASA / NORAD      ‘Two-Line  Elements’  (TLE).

2.   Conversion  of  Keplerian  Element  Set  to  State  Vector  Set  and  Vice  versa   :    Applied  to  six  satellites,  LANDSAT 8,   SPOT 6,   CARTOSAT-2B,   ISS (ZARYA),   GSAT-14,   and   Moon .

3.   Computing  Satellite  Orbit  Keplerian  Element  set  at  Perigee   prior   to Epoch   :    Applied  to  six  satellites,  LANDSAT 8,   SPOT 6,   CARTOSAT-2B,   ISS (ZARYA),   GSAT-14,   and   Moon .

For  complete  post  (Page  164  –  192)   Move   on  to   Website   URL   :


July 12, 2015

Position of Earth on Celestial Sphere at Input Universal Time

   Position   of   Earth  on   Celestial   Sphere  at   Input   Universal   Time

by  R C  Chakraborty,  July 12,  2015,  Pages  68 – 163.

(This  is  Sec. 4,   pp  68 – 163,  of  Orbital  Mechanics  –  Model  &  Simulation  Software  (OM-MSS),  Sec 1  to 10,  pp 1 – 402.)

Earth  is  a  sphere,  the  third  planet  from  the  Sun  and  the  fifth  largest  of  the  eight  planets  in  the  Solar  System.

Planets  order  from  the  Sun  :   Mercury,  Venus,  Earth,  Mars,  Jupiter,  Saturn,  Uranus,  Neptune.

Earth  Rotates  on  its  axis  passing  through  the  North  and  South  Poles.   The  rotation  is  counterclockwise looking  down  at  North  Pole.  This  rotation  results  daytime  in  area  facing  Sun  and  night  time  in  area  facing  away  from  Sun.   Since  we  are  on  Earth,   we  do  not  sense  its  rotation,  but  experience  by  observing  the  relative  motion  of  the  Sun  (like  from  a  moving  vehicle  we  see  the  surroundings  move).

The  time  for  Earth  to  make  a  complete  rotation  is  approximately  24  hours  (exactly  23.9344699  hours  or  23  hours,  56  minutes,  4.0916  seconds).   The  earth’s  orbit  around  the  sun  is  not  a  circle,  it  is  slightly  elliptical.   Therefore,  distance  between  earth  and  sun  varies  throughout  the  year.

To  Compute  the  Position  of  Earth  on  Celestial  Sphere  at  any  instant,   we  first  need  to  Compute  Position of  Sun  on  celestial  sphere  and  then  at  same  instant  Compute  Position  of  Earth  on  celestial  sphere.   For  the  Position  of  Sun  on  celestial  sphere,  much  has  been  computed / illustrated  in  previous  section  (Ref.

The  Position  of  Earth  on  celestial  sphere  is  characterized  by  computing  around  120  orbital  parameters.   The number  is  large,  because  some  parameters  are  computed  using  more  than  one  model  equation,   that  require  different  inputs.   This  helps  in  validation  of  results  and  understanding  the  different  input  considerations.

The  Orbital  Parameters  that  Characterize  the  Position  of  Earth  on  Celestial  Sphere,   are  put  into  following  groups   :

1.    GST   Greenwich   sidereal   time   and  GHA  Greenwich  hour  angle  in  0 to 360 deg,    at  input  UT  time   YY MM DD HH.

2.    Earth   Log   in  0 to 360 deg   and   Lat  in  +ve or -ve  in  0 to 90 deg   pointing  to  Sun  Ecliptic  Log (Lsun)   at  time  input  UT.

3.    LST  Local  sidereal  time  using  GST  over  three  longitudes,   Greenwich  log,  Sun  mean  log (Lmean),   &  Sun epliptic  log (Lsun) .

4.    ST0  sidereal  time  over  Greenwich  longitude  =  0.0,   at  time  input  Year  JAN  day 1  hr 00.

5.    ST  sidereal  time,   at  time  input  UT,   over  three  log,  Greenwich  log,   Sun  mean  log (Lmean),   and  Sun  epliptic  log (Lsun).

6.    H  hour  angle  in  0 to 360 deg  using  ST  over  five  longitudes,   Greenwich,   Lmean,   Lsun,   Earth  Sub  Sun  point  SS,   Earth  Observation  point  EP,   at  time  input  UT.

7.    Delta  E  is  Equation  of  Time  in  seconds,   using  p_julian_day,   n_sun,   w_sun  at  time  input  UT.

8.    GST  Greenwich  sidereal  time,   and  GHA  Greenwich  hour  angle  0 to 360 deg  at  time  when  earth  is  at  perihelion.

9.    ST  sidereal  time  &  MST  mean  sidereal  time  at  different  instances,  using  Earth  mean  motion  rev  per  day  and  Julian  century  days  from  YY  2000_JAN_1_hr_1200.

10.   Earth  orbit  radius,   sub  sun  point  on  Earth  surface  &  related  parameters,   using  SMA,   e_sun,   T_sun,   w_sun etc.

11.   Earth center(EC) to Sun center(SC) Range Vector [rp, rq, r]   in PQW  frame (perifocal  coordinate  system).

12.   Transform_1  Earth  position  EC  to  SC  Range  Vector [rp, rq]  in  PQW  frame  To  Range  Vector [rI, rJ, rK]  in  IJK  frame  (inertial system cord).

13.   Transform_2  Earth  point  EP (lat, log, hgt)  To  EC  to  SC  Range  Vector [RI, RJ, RK, R]  in IJK frame.

14.   Transform_3  Earth  position  EC  to  SC  Range  Vectors [rI, rJ, rK]   &   [RI, RJ, RK]  To  EP  to  SC  Range   Vector [rvI, rvJ, rvK]  in  IJK  frame.

15.   Transform_4  Earth  point  EP  to  SC  Range  Vector [rvI, rvJ, rvK]  in  IJK  frame  To  EP  to  SC  Range Vector [rvS, rvE, rvZ]  in  SEZ  frame.

16.   Elevation (EL)   and   Azimuth (AZ)  angle  of  Sun  at  Earth  Observation  point  EP.

17.   Distance  in  km  from  Earth  observation  point (EP)  to  Sub  Sun point (SS)  and  Earth  Velocity  meter  per  sec  in  orbit  at  time  input  UT.

18.   Earth  State  Position  Vector [X, Y, Z]  in  km  at  time  input  UT.

19.   Earth  State  Velocity  Vector [Vx, Vy, Vz]  in  meter  per  sec  at  time  input  UT.

20.   Earth  Orbit  Normal  Vector [Wx, Wy, Wz]  in  km  and  angles  Delta,   i,   RA   at  time  input  UT;   Normal  is  line  perpendicular  to  orbit  plane.

21.   Transform  Earth  State Vectors  To  Earth  position  Keplerian  elements.

22.   Transform  Earth  position  Keplerian  elements  To  Earth  State  Vectors .

The  values  of  all  these  parameters  are  Computed  are  at  Standard  Epoch  JD2000  and  when  Earth  is  at  Perihelion,  Aphelion,  Equinoxes,  and  Solstices.   The  time  at  perihelion,  aphelion,   equinoxes,  and  solstices,  were  computed  earlier  for  the  input  year  in  section 2.  (Ref.

For   complete   post   (Page 68 – 163)   Move   on   to   Website   URL  :


July 11, 2015

Position Of Sun on Celestial Sphere at Input Universal Time

   Position   Of   Sun   on   Celestial   Sphere   at   Input   Universal   Time

by  R C  Chakraborty,  July 11,  2015,  Pages  57 – 67.

(This   is   Sec. 3,   pp 57 – 67,   of   Orbital   Mechanics  –   Model   &   Simulation   Software  (OM-MSS),   Sec 1  to 10,  pp 1 – 402.)

Sun  is  a  star  at  the  center  of  our  Solar  System.   Although  stars  are  fixed  relative  to  each  other,  but  Sun moves   relative   to   stars.

Sun   follows   a   circular  path  on  the  celestial  sphere,  once  a  year.   This  path  is  known  as  the  ‘Ecliptic’, representing  the  plane  of  the  Earth’s  orbit.

The  Inclination   of   the  Earth’s  equator  to  the  Ecliptic  (or  earth’s  rotation  axis  to  a  perpendicular  on  ecliptic) is  called  Obliquity  of  the  ecliptic.

The  Obliquity  of  the  ecliptic  is  currently  23.4392794383  deg   with  respect  to  the  celestial  equator,  at standard  epoch  J2000 .

The   position   of   any   point   on   the  Celestial  Sphere   is   given  with  reference   to   the   equator  or  the  ecliptic.

The  Earth  moves  in  an  elliptical  orbit  around  the  Sun.   Therefore  the  distance  from  Earth  to  Sun  is  not same   at   all   points   on   the   orbit.

(a)   Find   Julian   day   of   interest   corresponding   to   the   input   Universal   Time;

(b)  Find  Corresponding  Ecliptic  coordinates  :   Mean  anomaly  of  the  Sun,  Mean  longitude  of  the  Sun, Ecliptic   longitude   of   the   Sun,

      Ecliptic  latitude  of  the  Sun  is  always  nearly  zero,   Distance  of  the  Sun  from  the  Earth  in  astronomical   units,   Obliquity   of   the   ecliptic

(c)   Find   Corresponding   Equatorial   coordinates   :    Right ascension,    Declination.

In  addition  to  these  Ecliptic  and  Equatorial  coordinates,   computed  many  other  parameters  related  to  Sun’s Position  on  Celestial  Sphere.

The   Position   of   Sun   on   Celestial   Sphere   is   represented   by   computing   following  parameters   :

 1.     Semi-major axis (SMA),                  2.    Mean movement per day (n sun),      3.     Mean distance (As),

 4.     Mean anomaly (m sun),                  5.     True anomaly (T sun),                         6.     Eccentric anomaly (E sun),

 7.     Right ascension (Alpha),                 8.     Declination (Delta),                               9.     Mean longitude (Lmean),

 10.   Ecliptic longitude (Lsun),                11.   Nodal elongation (U sun),                   12.   Argument of perigee (W sun),

 14.   Obliquity of ecliptic (Epcylone),     14.   Mean dist (d_sun),                               15.   Radial distance (Rs).

For   complete   post   (Page 57 – 67)     Move    on    to    Website    URL   :

Positional Astronomy – Earth Orbit around Sun

   Positional   Astronomy  –  Earth  Orbit  around   Sun

by   R C  Chakraborty,   July 11, 2015,   Pages 33 – 56.

(This  is  Sec. 2,  pp 33 – 56,   of   Orbital   Mechanics  –  Model   &   Simulation   Software  (OM-MSS),   Sec.  1  to 10,   pp  1  –  402.)

Positional  Astronomy  is  measurement  of  Position  and  Motion  of  objects  on  celestial  sphere  seen  at  a particular  time  and  location  on  Earth.   The  Positional  Astronomy,  also  called  Spherical  Astronomy,  is  a System  of  Coordinates.

The  Earth  is  our  base  from  which  we  look  into  space.   Earth  orbits  around  Sun,  counterclockwise,  in  an elliptical  orbit  once  in  every  365.26  days.  Earth  also  spins  in  a  counterclockwise  direction  on  its  axis  once every  day.   This  accounts  for  Sun,  rise  in  East  and  set  in  West.   Earth  Revolution  refers  to  orbital  motion  of the  Earth  around  the  Sun.   Earth  axis  is  tilted  about  23.45 deg,  with  respect  to  the  plane  of  its  orbit,  gives four  seasons  as  Spring,  Summer,  Autumn  and  Winter.

Moon  and  artificial  Satellites  also  orbits  around  Earth,  counterclockwise,  in  the  same  way  as  earth  orbits around  Sun.

In  the  early  1600s,  Johannes  Kepler  proposed  three  laws  of  planetary  motion.

First  Look  at  the  Preliminaries  about  ‘Positional  Astronomy’,  before  moving  to  the  computation  &  predictions of  astronomical  events.

Preliminaries  about  Positional  Astronomy  :  Explained  Celestial  Sphere,  Celestial   coordinates, Horizontal  Coordinate  system,   Equatorial  coordinate  system,   Ecliptic  coordinate  system,   Celestial  Orbit,   Orbit  Elements  or  Parameters,  State vectors  (Positions & Velocities)  at  Epoch,   Kepler  elements  (Inclination, Longitude of ascending node,   Argument  of  periapsis,   Eccentricity,   Semi-major  axis,   Mean  Anomaly)  at  Epoch, Heliocentric  Orbit  Characteristics   and   Orbit  Events (Equinox,  Solstice,  and  Seasons).

Prediction of Astronomical Events :   Computing  Anomalies,   Equinoxes,   Solstices,   Years   &   Seasons .

The  precise  time  of  occurrence  of  following  astronomical  events  at  input  UT,   Year   :

(a)   Earth  orbit  Mean  anomaly,   Eccentric  anomaly,   True  anomaly;

(b)   Earth  reaching  orbit  points,   Perihelion,  Aphelion,   Vernal Equinox,   Autumnal  Equinox,   Summer  Solstice,   Winter  Solstice;

(c)   Earth  reaching  orbit  points,   Semi-Major Axis,   Semi-Minor Axis;

(d)   Astronomical  years,   Anomalistic  Years,   Tropical  Years,   Sidereal  Years;

(e)   Earth  orbit  oblateness,   Semi-Major Axis,   Semi-Minor Axis;

(f)   Four  Seasons,   Start  time  of  Spring,   Summer,   Autumn,   Winter.

For   complete    post   (Page 33 – 56)    Move   on   to    Website   URL   :

July 10, 2015

Astronomical Time Standards and Time Conversions

   Astronomical  Time  Standards  and  Time  Conversions

by  R C  Chakraborty,   July 10, 2015,   Pages 6 – 32.

(This  is  Sec. 1,  pp 6 – 32,   of   Orbital   Mechanics  –  Model   &   Simulation   Software  (OM-MSS),   Sec.  1  to 10,   pp  1  –  402.)

First  Look  into  few  preliminaries  and  then  time  conversion  utilities.

Time  is  a  dimension  in  which  the  events  can  be  ordered  from  the  past  through  the  present  into  the  future.    Our  clocks  are  set  to  run  (approximately)  on  solar  time  (sun  time).    For  astronomical   observations,   we  need  to   use   sidereal   time  (star  time).

Time  Standards  and  designations   :   Solar Time,   Sidereal  Time,   Equation  of  time,   Precession,   Nutation,   Hour Angle HA,   GMT,   GMST,   LMT,   LMST,   Universal  Time  UT,   International  Atomic  Time  TAI,   Ephemeris  Time  ET,   Gregorian  calendar,   Julian  Day  JD.

The  Precise  time  conversion  utilities  :

*   Conversion  of  Universal  Time  To  Julian  Day;

*   Conversion  of  Julian  Day  To  Universal  Time;

*   Conversion  of  Fundamental  Epoch  To  Julian  day  and  Julian  century;

*   Add  or  Subtract  time  (days,  hour,  minute  seconds)  to  or  from  input  time;

*   Julian  day  for  start  of  any  Year;

*   Solar  Time  :   Local  Mean  Solar  Time  (LMT)  over  observer’s  Longitude;

*   Sidereal  Time  :   Greenwich  universal  time  at  hour  0.0  (ST0)   and   GMST;

*   Greenwich  Sidereal  Time  (GST),   Hour  Angle  (GHA)  &   Mean  Sidereal  Time  (MST);

*   Local  Mean  Sidereal  Time  (LMST)   over  observer’s  Longitude ;

*   Time  Conversions  :   LMT  to  LST,    LST  to  LMT,   LMT  to  LMST,   LMST  to  LMT .

For  complete  post  (Page 6 – 32)   move  on  to  Website  URL :

July 9, 2015

Introduction to OM-MSS Software

   Introduction  to  OM-MSS  Software

by   R C  Chakraborty,   July 09, 2015,   Pages 1 – 5.

Earth,   Sun,   Moon   &   Satellites   Motion   in   Orbit  –   Model   &   Simulation   Software.

We  look  into  space  from  Earth,  which  is  3rd  planet  from  Sun.    Earth  takes  around  365.25  days  to  moves around  Sun  in  an  Elliptical  orbit.   The  average  distance  from  the   Earth  to  the  Sun  is  called  one  Astronomical Unit (AU);  1 AU = 149,597,870.7 km.   Mars   is  4th   planet  from  Sun,  that  takes  686.971  Earth days  to  orbit  around  Sun.   The  orbital  path  of  Mars  is  highly  eccentric.   Mars  &  Earth  move  along  their orbits,  and  come  near  to  one  another  approximately  every  two  years.   This  approach  of  coming  near  facilitate  launching  of  spacecraft  every  two  years,  even  that  takes  about  eight  months  to  reach Mars. Example :  On Apr. 08, 2014,  the  near  or  close  distance  between  Mars  and  Earth  was  92.4  million  km.   Moon moves  around  Earth  in  the  same  kind  of  orbit.   The  Moon  is  the  Earth’s  only  natural  Satellite.   The  average distance  of  the  Moon  from  the  Earth  is 384,403 km.   A  Satellite  is  an  artificial  object,  intentionally  placed  into  orbit.   Thousands  of  Satellites  are  launched  into  orbit  around  Earth.   A  few  Satellites  called  Space  Probes have  been  placed  into  orbit  around  Moon,  Mercury,  Venus,  Mars,  Jupiter,  Saturn,  etc.   Understanding  the motion  of  Earth  around  Sun,  and  the  motion  of  Moon  and  Satellites  around  Earth  is  of  interest  to  many.

The  OM-MSS  is  a  software  that  simulates  motion  of  Earth,   Moon  &  Satellites   in   their   respective  Orbits  with  respect  to Sun.   The  Software  is  written  in  ‘C’  Language.  The  Compiler  used  is  Dev  C++  and  the Platform  is  a  Windows 7,  64 bit  Laptop.  The  Source  Code  around  30,000 Lines,  is  Compiled.  The ‘OM-MSS.EXE’  File  generated  is  of  Size 1.5 KB.  The  Executable  File, < OM-MSS.EXE >,  is  RUN  Step-by-Step for  a  Set  of  Inputs.   The  execution  of  ‘Orbital  Mechanics – Model & Simulation  Software  (OM-MSS)’,   illustrates  its  Scope,  Capability,  Accuracy,  and  Usage.   The  OM-MSS  Software  is  quite  exhaustive  for beginners,  experts,  researchers  &  professional  in  Spherical  Astronomy.   The  source  code  of  OM-MSS  Software  in  full  or  in  parts  has  a  cost  if  there  is  buyer.  The  cost  has  not  been  evaluated / decided.   The OM-MSS  Software  includes  the  following :

(a)   Astronomical  Time  Standards  and  Time  Conversions  Utilities :

GMT – Greenwich Mean Time,  LMT – Local Mean Time,   LST – Local Sidereal Time,   UT – Universal Time,

ET – Ephemeris Time,   JD – Julian Day,   Standard Epoch J2000,   Gregorian Calendar date   and  more.

 (b)   Positional  Astronomy  of  Earth,   Sun,   Moon,  and  Satellites  Motion  in  Orbit,  includes  computations  of  :

* Position  of  Sun  and  Position  of  Earth  on  Celestial  Sphere  at  Epoch ;

* Keplerian  elements :  Inclination,  RA  of  asc.  Node,   Eccentricity,   Arg. of Perigee,   Mean Anomaly,   Mean Motion;

* Motion  Irregularities :  Mean,  Eccentric  and  True  anomaly  in  deg;

* Precise  Time  at  Earth  Orbit  Points :  Perihelion,  Aphelion,  Equinoxes,  Solstices,  Semi-Major  & Minor-axis;

* Astronomical years :  Anomalistic,  Tropical,  and  Sidereal  Years;

* Four Seasons :  Spring,  Summer,  Autumn  and  Winter  start  time  and  duration;

* Position  of  Satellites  around  Earth  :  Keplerian  elements  and  State  Vectors  at  epoch,  and  computing, Sub-Sat point lat / log, EL & AZ angles,  Distances,  Velocity,  and  more;

* Satellite Pass,  Ground  Trace  for  Earth  Stn  using  NASA/NORAD  2-line  bulletins;

 (c)   Customized  Utilities  and  products  :  On  special  request  either  developed  or  configured  and  generated.

These  are  Presented  in  Section  –  1  to  8.    The  Section – 9  contains  References,  and  Section – 10  contains   few related  Diagrams.

For   complete   post  (Page 1 – 5)     Move    on    to    Website    URL :

Orbital Mechanics – Model & Simulation Software (OM-MSS)

   Orbital   Mechanics   –   Model   &   Simulation   Software  (OM-MSS)

by  R C  Chakraborty,   July 09,   2015,   Page 1 – 402.

A   Monograph  of   Earth,   Sun,   Moon   &   Satellites  Motion  in   Orbit.

Presented   the   Earth,  Sun,  Moon  &   Satellites  Motion  in  Orbit  –  Model  &  Simulation  Software   with Examples,    Problems    and    Software   Driven   Solutions.

The  Software  is  written  in  ‘C’ Language.   The  Compiler  used  is  Dev C++  and  the  Platform  is   a   Windows 7,   64 bit  Laptop.   The  Source  Code  around  30,000  Lines,   is   Compiled.    The ‘OM-MSS.EXE’   File  generated  is  of  Size  1.5 KB.  The  Executable  File,  < OM-MSS.EXE >,   is  RUN   Step-by-Step  for  a  Set  of   Inputs.

The   execution   of   OM- MSS    illustrates   its   Scope,   Capability,   Accuracy,   and   Usage.

The  Results   seen   on   Computer   Screen   are   put   in   a   File,   that   in   effect   becomes    :

A   Monograph   of   Orbital   Mechanics   with   Examples,   Problems   and   Software   Driven   Solutions‘,   Page 1 – 402,   which  includes   the  following  :

*   Introduction   to   OM-MSS   Software

*   Astronomical   Time   Standards   and   Time   Conversions.

*   Positional   Astronomy  –  Earth  Orbit  Around  Sun,    Anomalies  &  Astronomical   Events  (Equinoxes,   Solstices,   Years   &    Seasons).

*   Position   of   Sun   on   Celestial   Sphere   at   input   universal   time  (ut).

*   Position   of   Earth  on   Celestial   Sphere   at   input   universal  time (ut).

*   Satellites  Orbit  Elements  –  Ephemeris,    Keplerian   elements,    State  vectors.

*   Satellites   Motion   Around   Earth  –   Orbital   &   Positional   parameters   at   epoch.

*   Satellite   Pass   for   Earth  Station  –   Prediction   of   Ground   Trace   Coordinates,   Look  angles,   Universal / Local   time  &  more.

For   complete    post  (Page 1 – 402)     Move    on    to    Website   URL   :

April 1, 2015

Website, Blogs, Social Sites : Create web presence in the world of Internet

Create Presence on Internet and World Wide Web.

This article will let you think and know – how to create web presence in the world of internet – what all you need, start from where, and the kind of efforts required. All these questions are answered in most simple way sharing practices.

What  is  World Wide Web ?

Internet is a global system of interconnected computer networks, which connects other computer networks that are private, public, academic, business, and government.

World Wide Web (‘WWW‘ or W3 or simply ‘Web‘) is an Information-sharing model, that is built on top of the Internet.

  • Web is a communication infrastructure where  web resources  are located and offered to the end-user.
  • Uniform Resource Identifier (URI/URL) is a string of characters provide a means for identifying a web resource.
  • Web pages, are web resources, may contain text, images, videos and web navigation features (hyperlinks).  Web pages are accessed with a software application called web browser running on the user’s computer.
  • Web browser is a software application that allows people to access, retrieve and view information on the internet. The information content on a web page can be text, an image, video, audio etc. The popular web browsers are Internet Explorer, Firefox, Google Chrome, Opera and Safari.
  • Search engine is software programs that search for websites based on keywords that the user types in. The search engine goes through their databases of information in order to locate information you are looking for. The popular search engines are Google, Bing, and Yahoo.
  • Internet servers or Web servers are computers that deliver web pages. Every web server has an IP address (example that is possibly converted to a domain name (example An IP address, displayed as four numbers (0-255) separated by periods, consisting 32-bit is known as Internet Protocol Version 4 (IPv4).
  • Web servers support specially formatted documents called HTML (HyperText Markup Language). The HTML formatted documents support links to other documents, as well as graphics, audio, and video files. This way it possible to move from one document to another simply by clicking on hot spots (links). Not all Internet servers are part of the World Wide Web.
  • URLs identify a web resources. While an URL,, is entered in a browser, means the request goes to a web server whose domain name is The server fetches the page named index.html, usually home page, sends it the browser. Any computer can be turned into a Web server by installing server software and connecting to Internet.

Readers may read more at :

  8. .

What  are  Web 1.0 ,   Web 2.0  and  web 3.0 ?

These are different versions of Web model technology .

  • Web 1.0 model is the traditional World Wide Web, described as the ‘read only web’, a centralized or static website where users simply viewed or downloaded the content.
  • Web 2.0 model is described as the ‘read / write web’, allows users to interact, collaborate and share information with each other in social media that accepts community-based input.
  • Web 3.0 model refers to future, where computers interpret information like humans and intelligently generate and distribute useful content tailored to the needs of users.

Readers may read more at :


What  is  Website ?   What  a  Website  consists ?

Website is a collection of related World Wide Web (WWW) files called web pages typically served from a single web domain.

  • First step in making a website is to register a domain name that will usually be the website name. Example where the suffix ‘.info‘  signify a ‘resource‘ web site category. The cost for domain registration vary, the minimum can be $10 per year.
  • Website needs to be connected to the internet called hosting website on a Web server so that people can see it. A website hosting package can cost between $100 and $200 per year. A web server (example is a remote computer accessible through an internet address.
  • Web pages may contain long text, graphics, mathematical formulations, images, videos, and other multimedia components. Web pages includes hypertexts and links to other web pages and websites. Webpage can be made without knowing Hyper Text Markup Language (HTML). However, you need to know HTML to fix some inevitable problems.
  • URL is a string of characters used to identify a web page (file handle); example URL identify a web page named ‘courseware’ .
  • Web browser retrieve web pages from web server accessed through URL and display on computer screen. A website page may contain a hyperlink to any other website page.
  • Websites are typically dedicated to a particular topic or purpose, reflecting the work of an individual or a business or an organization. That way, a website can be a personal website, a commercial website, a government website or a non-profit organization website.
  • Website contents are most important for which people come to website or web page. Web contents do not come from web designs and web architectures etc. Web contents are specifically written by experts.
  • Traditional websites are static website,  based on Web 1.0 model technology which is not enough for user to interact.

Readers may read more at :

  1. ;

What  is  Blog ?   What a blog consists ?

Blog is a place for individuals to share thoughts on World Wide Web. Blog is an easy way for people, with a computer and internet access, to publish information in whatever form they want, a long text, images, videos etc. Blog is typically easier and cheaper to setup than website. Writing and publishing a blog need no knowledge of computer. Blogging platforms allow you to do all yourself and post your blog, without learning or developing any code (HTML). Blogging platforms offer hosting of a blog.

  • Blog consists a series of discrete entries called ‘posts’ published on the  World Wide Web.
  • The blog posts, in a default setup, appear in reverse chronological order where the most recent one showing first.
  • The posts are organized into few select category, for convenient browsing.
  • The comment forms appears at the end of every post for readers to interact, give feedback.
  • Blog are regularly written, the contents are mostly informational as news items and articles that are relevant for a short period.
  • Blogging platforms offer free as well as premium upgrade accounts for hosting blogs. The popular blogging platforms are WordPress,   Blogger, Tumblr, Twitter, YouTube.
  • WordPress, Blogger and Tumblr are large blogging platforms, have many features that allow users to change the look and functionality similar to website. The features include transfer of domain name, large storage, static pages, categories & tags, imports, comments & feedback.
  • Twitter is a Micro-blogging platform which allows blogging not more than 140 characters in a single post called ‘tweet’.
  • YouTube is a Video blogging platform which allows blogging short video clips of under 10-15 minutes in a single post.

Readers may read more at :


What are Social media and Social networking sites ?

Social media and Social networking are not same, while many use these two terms interchangeably. In social media you broadcast to reach large audience while in social network you create profiles or groups or fan pages.

Social  media

  • Social media is a way to transmit, or share information with wide audience. Social media is a strategy and a channel for broadcasting information. Social media is not a location that you visit. Social media sets a process to build a chain of influenced audience. Social media disseminates information that may influence others to repeat.
  • Social media builds the chain of influenced audience so long they find the media is a source of relevant and trusted information.
  • Social media stops building the chain of influenced audience while media is a source of irrelevant and not trusted information, the chain is broken, the media is downgraded and your information or expert knowledge will not reach to your audience.
  • Social media sites :,   diigo,   Digg, StumbleUpon,   Reddit,   and  more.

Social  networking

Social networking sites have changed the web with an opportunity to contribute or participate in a two-way communication. Social networking is an act of engaging of groups of people with common interests. Social networking services connect people around the world with different backgrounds, interests, hobbies and professions. On Social networking sites,  like-minds associate together and build relationships through community.

  • Social network sites are web-based services that enables users to create public profiles within his Website and form relationships with other users of the same Website service who access their profile.
  • The world’s leading Social networking sites are Facebook, MySpace, Twitter, LinkedIn, Flickr, Bebo and more.
  • Facebook has around a billion active users. Facebook has several add-on capabilities that allow users to combine their professional and personal aspects and invite/connect with fans and friends.
  • Twitter has around 300 million active users. Twitter is for real-time news sharing with a 140-character text limit. Twitter is described as the SMS of the Internet. The Tweets are publicly visible by default, but senders can restrict message delivery to just their followers.
  • LinkedIn has around 300 million active users. LinkedIn is top source for career, where users outlining education and work experience, make connections with other professionals, interact in group discussions, post job ads or apply for jobs.

Note : Social media and social networking work collectively in one umbrella known as Web 2.0. They work together, one cannot reach to its potential without the other.

Readers may read more at :


Creating   Web  Presence

Web Presence, internet presence and online presence, are different names but carry same meaning. Web Presence is defined on Wikipedia as being ‘the appearance of a person or organization on the World Wide Web.’ Creating web presence is the most basic reason for building a website. The success in web presence is measured by web analytics software, which indicates search engine ranking, traffic, popularity, backlinks and more.

  • Website alone cannot ensure success in web presence. Website is just one component of a complex network of information.
  • Website is relatively static, presents long lasting contents that need to be endorsed, publicized and communicated to people.
  • Blog posts are great, nice way to announce, present bulletins or spread information online. Blog when used correctly becomes an effective tool for promoting website contents.
  • Social media and Social networking are the other big thing in the world of Internet. Social media is a way to transmit, or share information with a broad audience, while Social networking engage groups of people with common interests and build relationships through community.  The social sites are ideal places to publicize blog and website contents.

Note : Depends on what you need, you may create any one or all of these – a traditional Website, one or more Blogging sites, and one or more Social sites. Examples below, are my own website, blog, social media & social networking sites.

(a) Creating Website :   Example –

The web URL is a personal website that offers free online learning resources to world wide students and educators. The web content are mostly courseware, teaching material, lecture slides, distributed over several pdf files consisting thousands of pages having text, graphics and mathematical expressions. The contents are long-lasting and therefore the website is updated only with new contents. The Website, follows a hierarchical structure representing a family tree of page icons, is described below.

  • The first big task for starting a website is choosing and buying a domain name . I have chosen and purchased a domain name, that is easy to remember, type, fits best to my web contents and the website readers/users.
  • The web contents are my lecture notes, invited talks, articles, opinions, etc. The website is to attract readers mostly students, teachers and professionals. The website to offer information about few selected technology, science, education, career and issues. Thus domain name ‘’  looked appropriate for my website.
  • In March 2008, purchased domain name ‘’ from domain registration company for period of ten years.
  • Website design software, tools and resources were purchased from ‘Netobjects Fusion Essentials and learned just enough to create and manage my own site.
  • The Website follows a hierarchical structure representing a family tree of page icons.  The pages have parent, child, and sibling relationships.
  • The web pages title appear in title bar & master borders as buttons, banners and drop down menu for navigation, and emphasized in search engine queries.
  • The web pages are arranged in three levels as 0, 1, 2 . The pages named at each level are follows.

           (1) Home page is default as index.html at root level, URL

           The next level-1 pages are children of parent Home page:

            (1.1) Courseware,   (1.2) Tech. Sci. , (1.3) Education, (1.4) Career, (1.5) Current Issue, (1.6) Site Map .

            Again each of these children are the parent of next level pages seen in drop down and side ways menu .

            The next level-2 pages as siblings of parent page (1.1) Courseware :

            (1.1.1) Artificial Intelligence, (1.1.2) Soft Computing, (1.1.3) Image Proc & C V, and (1.1.4) Projects . are siblings of parent

            The next level-2 pages as siblings of parent page (1.2) Tech. Sci :

        (1.2.1) Remote Sensing, (1.2.2) Communication, (1.2.3) Computer,   (1.2.4) Electronics and (1.2.5) Orbital Mechanics.

             The The next level-2 pages as siblings of parent page (1.3) Education :

            (1.3.1) Core Subjects , (1.3.2) Assignments .

             The next level-2 pages as siblings of parent page (1.4) Career :

              (1.4.1) Engineering , (1.4.2) Management , (1.4.3) Opportunities .

              The next level-2 pages as siblings of parent page (1.5) Current Issue :

              (1.5.1) Local Issues, (1.5.2) Global Issues .

              The next level-2 pages as siblings of parent page (1.6) Site Map :

              (1.6.1) Site Structure, (1.6.2) Feedback, (1.6.3) About Me .

  • Web contents are held as local in asset folders within website accessible by search engines. Asset folders contains mostly text & graphic files in WD, PDF and image formats, exceeding > 2000 pages. These are my lecture slides, notes, articles opinions, having long text, graphics, equations, hypertexts and links to other web pages and websites.
  • Managing assets means  view, add, delete, link file, data objects and variables from pages on which these appear. Valuable web content and its management, together add quality, credibility and reliability to any website.
  • META tags are inserted in every page. The tags are  what browsers, search engines and other web services look for.
  • XML sitemap support provided for web crawlers to discover site content; (Ref ).
  • Host for the website :  In Dec. 2009, registered with Web Host company for hosting the website. The justhost (hardware) is located at USA, ensures security and committed uptime. The web hosting is renewed recently, the renewal package cost is about $350 for a period of four years.
  • The website is submitted to popular search engines, Google, Yahoo, and Bing (MSN) to gain visibility. Search engines and web crawlers, robots look for HTML Navigation Links, meta tags, and XML sitemap support to discover site content. (Ref ).
  • A credible website appears on first page of one or more search engine which requires lot many checks and actions. The online website reviews, recommendations, ratings, ranked lists services are used for this purpose. Remember these are because of web contents that are most important for which people come to website.
  • Finally, the growing presence of the website on internet is reflected in global traffic rank measured by the popular (Alexa) web analytics. The global traffic rank measured for this website are : Worldwide Rank 2,530,226, Rank in United Kingdom 1,285,027, Country Rank 157,639 on March 23, 2015.   (Ref ).

(b)   Creating Blog :   Example – www.

The web URL is a Blog created using WordPress open-source blogging tool available free for registered users. A blog includes text, images, and links to other blogs, Web pages, and other media related to its topic.

  • In March 2007, sign up with a blog service provider ‘WordPress’  to build a free site.
  • User name ‘myreaders’ ,  address ‘’ as free sub domain that never expires, and free space 3 GB.
  • Blog consists 6 sections called ‘pages‘ to write on about the ‘posts‘. The blog pages show quasi-static contents.
  • Blog pages are named as ‘Home’,   About ME’,  Courses’,  Science & Technology’,  Education  & Research’, ‘Opportunity’ ,   Issues’.
  • Blog posts are the series of discrete entries that appear on the World Wide Web. The blog posts are organized into 10 groups  called ‘category’  for convenient browsing and display posts.
  • Blog categories are  ‘World of Internet’,   ‘Artificial Intelligence’, ‘Soft Computing’, ‘Comp. Vision & Image Proc’, ‘Electronics & Comm.’ ,   ‘Computers’, ‘Remote Sensing’, ‘Orbit & Space Tech’.,  ‘Projects & Proposals’,   ‘Education & Opportunity’,   ‘Opinion’.
  • All blog posts appear in reverse chronological order (most recent one showing first), by default setup in category NIL – All Posts.

(c)   Creating   Social  media  sites :   Delicious,  Diigo.

The and Diigo are world’s leading social bookmarking services for storing, sharing and discovering bookmarks of web resources/content. I started with Delicious and later added Diigo which offers all features of delicious and even more. These two social media broadcast my website contents to reach large audience.

(d)   Creating   Social  networking  sites :  Facebook,  Twitter,   LinkedIn

Social network sites are web-based services that enables users to create public profiles within his Website and form relationships with other users of the same Website service who access their profile. The top three Social network sites are Facebook, Twitter and LinkedIn. Each of these three serve different purpose. Facebook invite and connect with fans and friends. The Tweets are publicly visible by default. LinkedIn is top source for career, where users outline their work experience to make connections with other professionals. I have used these three social networking services to project the public profiles of my website contents.

Here a question asked – Should Website, Blog and Social sites be stand-alone coordinated entities or combined ?

There are many conflicting views in this regard. I have no need of combine or integrate Website, Blog and Social sites, nor I am sure of the prose and cons of doing so. I regard these as stand-alone, separate and independent entities stacked in a pyramid in the order they are evolved.

  • The Website, Blog and Social sites – All stand-alone coordinated entities in a pyramid structure where the Website is at the bottom, the Blog is in the middle, and the Social media & networking sites at the top.
  • The Website HTML Navigation Links, meta tags, XML sitemap support web crawlers to discover site content and responsible to generate enough traffic.
  • The Blogs are more ‘search engine friendly’ than websites. I write my blog pages and postings in a way, to drive traffic towards my website. The links that come from blog and focused into website  have additional value because they come from an external site of appropriate content and good quality.
  • The social media created public profile of the website (titles, key words, abstracts and links) and shared with wide audience that enables users to build relations or form groups over social networking sites.

Creating  Brand  name  ‘myreaders’  for  growing  presence  on  internet

The world of internet consists millions of Websites. Today making website is easy. Anyone can have a Web site, but how do you know which site to bookmark or worth visiting again and again ? The answer is branding, a promise, an assurance of worth visiting a website URLs more than once. Note that the sites visitors go back to are the sites they trust. However, a website to earn visitor’s trust is difficult but essential. Here are some pre-requisites that I followed and make efforts to build my website worthy of trust.

  • Web identity is domain name, that is an integral part of website, must be short, relevant, and memorable to prospective visitors. My web domain name is  ‘’ .
  • Web contents attract visitors, must be focused, rigorous on few specific subjects / topics. My web contents include a fair amount of courseware, teaching materials, lecture slides/notes, articles, address on specific technology, and links to other websites.
  • Website look must be professional, so that visitors stick around to explore the site further. My website is supported with page icons, banners, title bar & master borders, buttons, drop down menu, asset folders, meta tags, managing view, add, delete, links to file, data objects & variables etc. Thus the site is not just friendly to users, but to web crawlers and search engines to discover site content.
  • Credible human elements behind website earn visitor’s trust. My website is supported with ‘about me’,  contact page,  e-mail id,  feed back page.
  • Web server location is at Chicago, Illinois, United States. In Dec. 2009 registered with web host company, The website was hosted in January 2010.
  • Blog does online brand advertising, provides commentary on a particular subject, functions as personal online diary. My website is supported with two open-source blogs respectively on blogging platforms offered by wordpress, Blogger.

               – open-source blogs              wordpress


  • Social media transmit, or share information with a broad audience, while Social networking engage groups of people with common interests and build relationships through community. My website is supported with two social media sites and three social networking sites respectively – wordpress, Blogger, Delicious, Diigo, Facebook, Twitter, and LinkedIn.

                – social media sites               Delicious


                – social networking sites     Facebook



  • No matter what blog and social sites are, always ensured that blog and social sites URLs are in context with website domain name ‘myreaders’.
  • Finally, the performance the website domain can be seen  at following website review URLs :

                 – Overview 

                 – Rank in UK

                 – Domain report

                 – Site analysis

                 – Overview 

Conclusion :  Presented a very comprehensive article, that includes World Wide Web, Web model technologies, Creating website, Creating blog, Creating social media & social networking sites, Creating successful web presence and Creating brand name.

By R C Chakraborty, Former Dir. DTRL & ISSA, DRDO, Delhi, ,

January 19, 2015

DRDO Must Reform – the hard decisions need to be implemented

Filed under: 11. Opinion, NIL - All Posts — myreaders @ 9:15 am

DRDO Must Reform – the hard decisions need to be implemented

Look at few sequence of events :  (a)  The 38th DRDO Directors’ conference (25-26 Mar 2014);  (b)  The DRDO Awards Function on 20 Aug 2014 – Hon’ble PM Narendra Modi addresses DRDO scientists, stresses on innovation and technology and asks DRDO to complete projects in time;   (c)  DRDO chief sacked on 14 Jan 2015 (NDTV News Flash) – Analysts believe that the action could have been taken against the backdrop of Mr. Modi’s comment during a visit last year that the ‘laid back’ attitude in the DRDO would not be tolerated —.

After this, appeared several news in media titled,   “DRDO head should be younger”,   “Defence Ministry plans DRDO overhaul”,    “Government mulling to bifurcate DRDO chief and Scientific Adviser”, etc.

Yesterday, after reading an article title “DRDO needs to be agile, focused” in Times Of India (17 Jan 2015), I just recalled what I mentioned in one of my article, way back on 23 June 2007, still holds. Here I concluded, that DRDO must look for alternatives to its failures, which means DRDO to take few “hard decisions”. The same is reproduced below.

  1. All System Development projects and programs should be taken out of DRDO, because of very little R&D opportunity. The R&D element is just 10% while 90% is engineering design, fabrication, testing, integration, field trials, acceptance and management. Each of these are better done else where and not by R&D mind. The implementation responsibility would also lie on those who do these 90% work and finally on a Board. DRDO contribution, claim, responsibility, budget allocation, manpower, infrastructure, and management should relate to that 10% only.
  1. Further, the Most Technology Demonstration projects should also be taken out of DRDO. The reason is same said above. The R&D elements in these TD projects are just 40% or less. Indian industries, particularly the private sectors, offer better compensation and therefore have better human resources They would better absorb this 40% R&D elements along with rest 60% activity.
  1. Lastly, a few Technology Demonstration projects where R&D elements are 40% or more and all the S&T projects where R&D elements are 100%, there DRDO has it primary role that is : “Convert scientific know-how into usable technologies”. Here also DRDO need to evolve partner ship with the academic institutions, funded by government or privately managed. All such projects are identified as (a) Basic Research that produces new knowledge in scientific or technology areas of interest to the military and (b) Applied Research that supports the exploratory development of new technologies for specific military applications or further development of existing technology for new military applications. The procedures followed by DARPA can be adopted to ensue transparence, equal opportunity, accountability, quality and most importantly revealing what followed next.

Read Complete article, title ‘Scientist Leaving DRDO – Why call Attrition ?’

By R C Chakraborty, Former Dir. DTRL & ISSA, DRDO, Delhi,

April 26, 2008

Influence of Artificial Intelligence on Communication Systems

Influence of Artificial Intelligence on Communication Systems

An invited talk at Snow & Avalanche Study Establishment Research & Development Center (SASE RDC), Chandigarh, on April 16, 2008, by R C Chakraborty, Visiting Prof. JIET, Guna & Former Dir. DTRL & ISSA (DRDO). The Highlights of my talk :

(a) Timeline of Telecommunication related technology – Telegraph, Morse code, Telephone Exchange, Wireless telegraphy, Iconoscope, Television system, Radio networks;

(b) Timeline of Artificial Intelligence related technology – Roman Abacus, Pascaline, Diff. Engine, Boolean algebra, Turing machines, Von Neumann architecture, ENIAC;

(c) Timeline of AI events – Turing test, intelligent behavior, Logic Theorist, Birth of AI, General Problem Solver, LISP language, DoD’s Advanced Research projects, Micro-world program SHRDLU, Expert systems, Computer vision, Prolog ;

(d) Modern digital communications – geosynchronous communication satellites, packet switching theory, wide-area computer network, Optical fiber, Internet era, ARPANET, Birth of login – ‘log’ ‘in’, Protocol – TCP/IP, Internet;

(e) AI vocabulary – Intelligence, Intelligent behavior, knowledge is collection of facts, Learning is what facts or behaviors represent, Knowledge Model – a degree of connectedness & understanding that increase, we progress from data to information to knowledge and to wisdom;

(f) Building Intelligent Communication Systems – Seamless global network, Intelligent mobile platform, Voice-recognition across Mobile-phone, and Knowledge base Networking;

(g) Conclusion – We live in an era of rapid change, moving from information to knowledge based seamless global intelligent network of society.  The creation of intelligence in machine has been a long cherished desire to replicate the functionality of the human mind. Intelligent information and communications technology (IICT), emulates and employ some aspect of human intelligence in performing a task. The IICT based systems, include sensors, computers, knowledge-based software, human-machine interfaces and other devices. Today, intelligent systems applications exists virtually in all sectors where they deliver social as well as economic benefits.

For complete lecture slides move on to Website URL :


April 3, 2008

Artificial Intelligence – Knowledge Representation – issues, predicate logic, rules

Artificial Intelligence – Knowledge Representation, Issues, Predicate Logic, Rules

This is part of the courseware on Artificial Intelligence, by R C Chakraborty, at JUET. It consists eight hours of lectures. The topics are :

Knowledge Representation (KR) – introduction, knowledge progression, model, category, typology map, relationship, mapping, representation, schemes, relational, inheritable, inferential, declarative, procedural, attributes, relationship, granularity.

KR using Logic – predicate logic, propositional logic, statements, variables, symbols, connective, truth value, contingencies, tautologies, contradictions, antecedent, consequent, argument, expressions, quantifiers, formula, representing “IsA” and “Instance” relationships.

KR using Rules – declarative, procedural, meta rules, procedural verses declarative knowledge & language, logic programming characteristics, statement, language, syntax & terminology, data components, simple & structured data objects, program components clause, predicate, sentence, subject, queries, programming paradigms, model, computation, imperative model, functional model, logic model, reasoning, forward and backward chaining, conflict resolution, and control knowledge.

For complete course lecture slides move on to Website URL :

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