Jump to content

User:Wikibob/Sandbox3

From Wikipedia, the free encyclopedia

Attempt at getting Deimos transit info from JPL Horizons.

Deciphering timestamps from Mars Rover image filenames

[edit]

[1] Explains the image filename fields, and we're interested in characters:

3 to 11   Spacecraft clock
        This is the number of seconds since January 1, 2000 
        at 11:58:55.816 UTC.

So from the Sol 30 March 4 Deimos transit image filenames.

If I've not made a miscalculation, and if Opportunity's onboard clock was correct, then UTC times for the 4 Deimos transit images were:

Mar 4 03:03:43 = Image 1 showing mid-transit
Mar 4 03:03:53 = Image 2 still in transit
Mar 4 03:04:03 = Image 3 approaching third contact
Mar 4 03:04:13 = Image 4 possibly between third and fourth contact

Compare with the 3 Opportunity images mentioned in IAU circular 08298:

Mar 4 03:03:56  Mar. 4.12773 UT  
Mar 4 03:04:06  Mar. 4.12785
Mar 4 03:04:16  Mar. 4.12819

Some calculations, MER-0 is 0 seconds for the Rover clock:

UTC decimal       HH:MM:SS  Julian Day     secs since MER-0
-----------------------------------------------------------
2000 Jan 1 noon =           2451545.0             64.184
2004 Mar 3 noon =           2453068.0      131587264.184 =1523 days +64secs
2004 Mar 4.127581 03:03:43  2453068.627581 131641487.0   = Image 1
2004 Mar 4.127697 03:03:53  2453068.627697 131641497.0   = Image 2
2004 Mar 4.127812 03:04:03  2453068.627812 131641507.0   = Image 3
2004 Mar 4.127928 03:04:13  2453068.627928 131641517.0   = Image 4

more notes...

Local Time  Filename                    Seconds
10:28:17    1P131641487ESF0544P2665R8M1 131641487 
10:28:27    1P131641497ESF0544P2666R8M1 131641497 

See Transit of Deimos from Mars and User_talk:Curps.

2 198.05 miles = 3 537.41858 kilometers
  564.48 miles = 908.442501 kilometers

Using Mars Rover Spirit's coords: -175.4833, 3537.41, 908.44

[edit]
Select ... [E]phemeris, [F]tp, [M]ail, [R]edisplay, ?, <cr>: 402
*******************************************************************************
 Revised: May 04, 1999             Deimos / (Mars)                          402

 SATELLITE PHYSICAL PROPERTIES:
  Radius (km)             = 7.8 x 6.0 x 5.1 Density (g cm^-3)   =  1.76 +- 0.30
  Mass (10^20 kg )        = 1.80 (10^-5)    Geometric Albedo    =  0.06 
                               (+- 0.15)    V(1,0)              = +12.89

 SATELLITE ORBITAL DATA:
  Semi-major axis, a (km) = 23.4632(10^3)   Orbital period      = 1.262441 d
  Eccentricity, e         =  0.00033        Rotational period   = Synchronous
  Inclination, i  (deg)   =  1.791
*******************************************************************************
Select ... [E]phemeris, [F]tp, [M]ail, [R]edisplay, ?, <cr>: e

 Observe, Elements, Vectors  [o,e,v,?] : o

 Coordinate center [ <id>,coord,geo  ] : Spirit@499

   #   E. Lon    DXY      DZ    Observatory Name
  --- -------- ------- -------  ----------------
     -175.4833 +219805 -056448  Spirit Landing Site (MER) / Gusev
 
 Confirm selected station    [ y/n ] --> y

 Starting UT  [ex: 1976-Jun-02 00:02 ] : 2004-Mar-09 15:50

 Ending   UT  [ex: 2025-Jan-10 23:56 ] : 2004-Mar-09 15:58

 Output interval [ex: 10m, 1h, 1d, ? ] : 1m
 
 Current output table defaults --
   Reference frame       = ICRF/J2000.0
   Time zone correction  = UT+00:00
   Time format           = CAL
   Time digits output    = MIN
   R.A. format           = HMS 
   RA/DEC extra precision= NO         
   Apparent coord. type  = AIRLESS    
   Range units           = AU  
   Suppress range-rate   = NO  
   Minimum elevation     = -90.0
   Maximum airmass       = 38.0000
   Rise-Transit-Set only = NO
   Skip daylight         = NO
   Solar elong. cut-off  = 0,180
   CSV spreadsheet output= NO
   Table quantities      = A
 
 Accept default output [ cr=(y), n, ?] : 

 Select table quantities [ <#,#..>, ?] :  4,5,13,23,34
 
 Working ...
*******************************************************************************
Ephemeris / PORT_LOGIN Thu Jun 17 16:17:25 2004  Pasadena, USA   / Horizons    
*******************************************************************************
Target body name: Deimos (402)                    {source: MAR033.DE405}
Center body name: Mars (499)                      {source: DE-0406LE-0406}
Center-site name: Spirit Landing Site (MER) / Gusev
*******************************************************************************
Start time      : A.D. 2004-Mar-09 15:50:00.0000 UT      
Stop  time      : A.D. 2004-Mar-09 15:58:00.0000 UT      
Step-size       : 1 minutes
*******************************************************************************
Center geodetic : -175.483300,   -14.5667,    -0.0{E-lon(deg),Lat(deg),Alt(km)}
Center cylindric: -175.483300,  3288.2360,  -844.4{E-lon(deg),Dxy(km),Dz(km)}
Center pole/equ : IAU_MARS                        {East-longitude -}
Center radii    : 3396.2 x 3396.2 x 3376.2 km     {Equator, meridian, pole}    
Target pole/equ : IAU_DEIMOS                      {East-longitude -}
Target radii    : 7.5 x 6.1 x 5.2 km              {Equator, meridian, pole}    
Target primary  : Mars                            {source: DE-0406LE-0406}
Interfering body: PHOBOS (Req= 13.400) km         {source: MAR033.DE405}
Deflecting body : Sun                             {source: DE-0406LE-0406}
Deflecting GM   : 1.3271E+11 km^3/s^2                                          
Atmos refraction: NO (AIRLESS)
RA format       : HMS

Previous attempt using DXY and DZ as KM when they were miles.

telnet ssd.jpl.nasa.gov 6775
...
Horizons> 402
*******************************************************************************
 Revised: May 04, 1999             Deimos / (Mars)                          402

 SATELLITE PHYSICAL PROPERTIES:
  Radius (km)             = 7.8 x 6.0 x 5.1 Density (g cm^-3)   =  1.76 +- 0.30
  Mass (10^20 kg )        = 1.80 (10^-5)    Geometric Albedo    =  0.06 
                               (+- 0.15)    V(1,0)              = +12.89

 SATELLITE ORBITAL DATA:
  Semi-major axis, a (km) = 23.4632(10^3)   Orbital period      = 1.262441 d
  Eccentricity, e         =  0.00033        Rotational period   = Synchronous
  Inclination, i  (deg)   =  1.791
*******************************************************************************
Select ... [E]phemeris, [F]tp, [M]ail, [R]edisplay, ?, <cr>: e
 
 Observe, Elements, Vectors  [o,e,v,?] : o
 Use previous center  [ cr=(y), n, ? ] : n
 Coordinate center [ <id>,coord,geo  ] : c@499
 Cylindrical or Geodetic input [ c,g ] : c
 Input units must be DEGREES and KILOMETERS --
   Specify cylindr {E. Long, DXY, DZ}  : -175.4833, +3198.05, -0564.48
 Starting UT  [ex: 1976-Jun-02 00:02 ] : 2004-Mar-09 15:50
 Ending   UT  [ex: 2025-Jan-10 23:56 ] : 2004-Mar-09 15:59
 Output interval [ex: 10m, 1h, 1d, ? ] : 1m

*******************************************************************************
Ephemeris / PORT_LOGIN Thu Jun 17 15:18:18 2004  Pasadena, USA   / Horizons    
*******************************************************************************
Target body name: Deimos (402)                    {source: MAR033.DE405}
Center body name: Mars (499)                      {source: DE-0406LE-0406}
Center-site name: (User Defined Site)
*******************************************************************************
Start time      : A.D. 2004-Mar-09 15:50:00.0000 UT      
Stop  time      : A.D. 2004-Mar-09 15:59:00.0000 UT      
Step-size       : 1 minutes
*******************************************************************************
Center geodetic : -175.483300,   -10.1318,  -148.0{E-lon(deg),Lat(deg),Alt(km)}
Center cylindric: -175.483300,  3198.0500,  -564.4{E-lon(deg),Dxy(km),Dz(km)}
Center pole/equ : IAU_MARS                        {East-longitude -}
Center radii    : 3396.2 x 3396.2 x 3376.2 km     {Equator, meridian, pole}    
Target pole/equ : IAU_DEIMOS                      {East-longitude -}
Target radii    : 7.5 x 6.1 x 5.2 km              {Equator, meridian, pole}    
Target primary  : Mars                            {source: DE-0406LE-0406}
Interfering body: PHOBOS (Req= 13.400) km         {source: MAR033.DE405}
Deflecting body : Sun                             {source: DE-0406LE-0406}
Deflecting GM   : 1.3271E+11 km^3/s^2                                          
Atmos refraction: NO (AIRLESS)
RA format       : DEG
 < Scroll & Page: space, <cr>, <b>ack, OR arrow keys. <q> ends display. > 20% 
Time format     : CAL 
RTS-only print  : NO       
EOP file        : eop.040617.p040908                                           
EOP coverage    : DATA-BASED 1962-JAN-20 TO 2004-JUN-17. PREDICTS-> 2004-SEP-07
Units conversion: 1 AU= 149597870.691 km, c= 299792.458 km/s, 1 day= 86400.0 s 
Table cut-offs 1: Elevation (-90.0deg=NO ),Airmass     n.a.    , Daylight (NO )
Table cut-offs 2: Solar Elongation (  0.0,180.0=NO )                           
*******************************************************************************
 Date__(UT)__HR:MN:SS     Azi_(a-appr)_Elev L_Ap_Sid_Time Ang-diam    S-O-T /r 
*******************************************************************************
$$SOE
 2004-Mar-09 15:50:00 *x  235.1606 -74.2769 14.1024935262  116.462 130.0487 /T 
 2004-Mar-09 15:51:00 *x  235.0815 -74.3112 14.1187385252  116.459 130.2516 /T 
 2004-Mar-09 15:52:00 *x  235.0020 -74.3453 14.1349835243  116.456 130.4545 /T 
 2004-Mar-09 15:53:00 *x  234.9223 -74.3795 14.1512285233  116.454 130.6573 /T 
 2004-Mar-09 15:54:00 *x  234.8422 -74.4136 14.1674735223  116.451 130.8602 /T 
 2004-Mar-09 15:55:00 *x  234.7618 -74.4477 14.1837185213  116.448 131.0630 /T 
 2004-Mar-09 15:56:00 *x  234.6810 -74.4818 14.1999635203  116.446 131.2659 /T 
 2004-Mar-09 15:57:00 *x  234.6000 -74.5158 14.2162085193  116.443 131.4687 /T 
 2004-Mar-09 15:58:00 *x  234.5185 -74.5498 14.2324535183  116.441 131.6716 /T 
 2004-Mar-09 15:59:00 *x  234.4368 -74.5838 14.2486985174  116.438 131.8744 /T