Project

General

Profile

Known time desc » History » Revision 18

Revision 17 (Anonymous, 08/07/2016 10:22 AM) → Revision 18/31 (Anonymous, 08/07/2016 10:54 AM)

h1. Known time description 

 h2. Double Time ranges : date from 01/01/1970 to 01/01/2100 

 * seconds from 01/01/1970 00:00:00    :                                                   0            to              4 102 488 000 
 * milliseconds from 01/01/1970 00:00:00    :                                            0            to      4 102 488 000 000      (ambiguity for the first 48days of 1970 with previous time format) 
 * seconds from 01/01/0000 00:00:00    :                         62 168 472 000            to            66 270 960 000 (no ambiguity) 
 * milliseconds from 01/01/0000 00:00:00 :          62 168 472 000 000             to 66 270 960 000 000 (no ambiguity) 
 * seconds from 01/01/2000 00:00:00    :                            - 946 728 000            to              3 155 760 000    (TT2000) 
 * milliseconds from 01/01/2000 00:00:00    :             - 946 728 000 000            to      3 155 760 000 000 (ambiguity with TT2000 in seconds?) 


 h2. Known time description 


 |_.Mission Name |_.time var name                     |_. units           |_.DEPEND |_.LABLAXIS|_.FIELDNAM                     |_.CATDESC                                                           |_.Type                           |_.VIRTUAL|_.nb of records|_.VAR_NOTES| 
 |Cluster FGM          |time_tags__CDFNAME       |ms                   |0                     |UT                   |Universal Time                 |Interval centred time tag                                      |CDF_EPOCH              |                       |normal                |field missing| 
 |Cluster HIA            |time_tags__CDFNAME       |ms                   |0                     |UT                   |Center Time                      |Interval centred time tag                                      |CDF_EPOCH              |                       |normal                |field missing| 
 |||||||||||| 
 |Themis Efi,SCM    |VARNAME_time                   |sec                  |TIME              |UT                   |Same as time var name|UTC, in seconds sinc 01-Jan-1970 00:00:00|CDF_DOUBLE            |                       |normal                |Unleaped seconds| 
 |Themis Efi,SCM    |VARNAME_epoch               |field missing|0                     |UT                   |Same as time var name|Unrelated                                                                |CDF_EPOCH             |true                |0                          |field missing| 
 |Themis Efi,SCM    |VARNAME_dot0_epoch0|msec               |EPOCH0      |UT                   |Same as time var name|EPOCH of THEMIS time base                             |CDF_EPOCH              |                       |1                          |EPOCH of 01-Jan-1970 00:00:00| 
 |Themis Esa            |VARNAME_time                   |sec                  |TIME              |UT                   |Same as time var name|UTC, in seconds sinc 01-Jan-1970 00:00:00|CDF_REAL8               |                       |normal                |Unleaped seconds| 
 |Themis Esa            |VARNAME_epoch               |field missing|0                     |UT                   |Same as time var name|Unrelated                                                                |CDF_EPOCH             |true                |0                          |field missing| 
 |Themis Esa            |VARNAME_dot0_epoch0|msec               |EPOCH0      |UT                   |Same as time var name|EPOCH of THEMIS time base                             |CDF_EPOCH              |                       |1                          |EPOCH of 01-Jan-1970 00:00:00| 
 |Themis Peer          |VARNAME_time                  |sec                   |TIME              |UT                   |Same as time var name|UTC, in seconds sinc 01-Jan-1970 00:00:00|CDF_DOUBLE            |                       |> data                  |Unleaped seconds| 
 |Themis Peer          |VARNAME_epoch              |field missing |0                     |UT                   |Same as time var name|VARNAME                                                              |CDF_EPOCH              |                       |normal                |field missing| 
 |Themis Peer          |VARNAME_epoch0            |msec                |EPOCH0      |timebase        |Same as time var name|EPOCH of THEMIS time base                             |CDF_EPOCH             |                       |1                          |EPOCH of 01-Jan-1970 00:00:00| 
 |||||||||||| 
 |MMS fpi                  |Epoch (absent, Epoch_minus_var is present)            |s                   |0                     |Field missing                   | VARNAME|VARNAME                        |CDF_UINT1                 |                       |1                           |VARNAME| 
 |MMS scm               |epoch_timetag                     |ns                     |0                     |VARNAME     |Same as time var name|Packet time time                                                    |CDF_TIME_TT2000|                       |normal                 |field missing| 
 |MMS scm               |Epoch    (other var time)       |ns                     |0                     |VARNAME     |Same as time var name|Time                                                                         |CDF_TIME_TT2000|                       |normal                 |field missing| 
 |||||||||||| 
 |ACE mfi                  |Epoch                                     |ms                   |0                     |VARNAME     |Time                                    |Time    ,beginning of interval                                 |CDF_EPOCH             |                       |normal                 |field missing| 
 |||||||||||| 
 |Helios nessmag |Epoch                                     |ms                   |0                     |field missing |Epoch                                 |Default Time                                                           |CDF_EPOCH             |                       |normal                 |field missing| 
 |||||||||||| 
 |Ulysses hft             |Epoch                                     |ms                   |0                     |Time                 |Epoch                                 |Time in NSSDC Epoch format                           |CDF_EPOCH             |                       |normal                 |field missing| 
 |||||||||||| 
 |SOHO cst               |Epoch                                     |ms                   |0                     |Epoch              |Time Line                           |Time                                                                       |CDF_EPOCH             |                       |normal                 |field missing| 


 h2. Algorithm Proposition 

 VariableThatNeedsTime 
 depend0 = get(VariableThatNeedsTime.DEPEND_0 variable) 

 if(depend0.nbOfRec == VariableThatNeedsTime.nbOfRec) 
              test depend0.firstValue for different double range mentionned above (this part might include CDF_TYPE for TT2000) 
              if(ambiguity) 
                       look at depend0.units 
                       if field is missing, look at VariableThatNeedsTime.depend_epoch0.units field 

 else 
 dependTime = get(VariableThatNeedsTime.DEPEND_TIME variable) 
 if(dependTime.nbOfRec == VariableThatNeedsTime.nbOfRec) 
             test dependTime.firstValue for different double range mentionned above (this part might include CDF_TYPE for TT2000) 
             if(ambiguity) 
                     look at dependTime.units