
================================================================================

CONTENT OF THE SPICAM/SPICAV IR 1A DATA STRUCTURE:	

================================================================================

 
    - "Cleandata" field:
    	This field represents the primary block of the FITS data and it contains
    	the clear data. The name given in the FITS file is CLEANDATA. This is
    	a 3-dimension float array containing the raw data corrected from the
    	Dark Current and saturation in ADU. The dimensions of the array
    	are: [NB_SPECT, NB_POINT, NB_CHANN]
     
   - "WL" field:
   	The first extension contains the wavelengths in nm corresponding to each
   	spectral point in CLEANDATA. The extension is a 3-dimension float array
   	with the same dimension as the CLEANDATA block. The wavelengths are
   	obtained based on RF frequency-wavelength calibration described.

   - "DC" field:
   	The second extension contains the Dark Current data in ADU. The name
   	given in the FITS file is DC. The extension is a 3-dimension float array
   	with the same dimension as the CLEANDATA block.
   	
   - "RAW" field:
   	The third extension contains the raw data in ADU corrected for the
   	saturation. The name given in the FITS file is RAW. The extension is a
   	3-dimension float array with the same dimension as the CLEANDATA block.
   	
   - "TIME_OF_RECORDS" field:
   	The fourth extension is a Binary Table and defines the time of records
   	(beginning of a spectrum record). The name given in the FITS file is
   	TIME_OF_RECORDS. It contains the time parameters of each data records in
   	a structured way. The size of the table is equal to NB_SPECT.
	o YEAR		INTEGER
	o MONTH		INTEGER
	o DAY		INTEGER
	o HOUR		INTEGER
	o MINUTE	INTEGER
	o SECOND	INTEGER
	o MSECOND	DOUBLE
   
   - "Info" sub-structure containing information about the
     input files and general observation characteristics  
	o INSTRU: 	STRING	Name of the instrument
	o ORBIT: 	INTEGER	Orbit number
	o SEQ_NB: 	INTEGER	Sequence number
	o STATUS: 	STRING	Status of the FITS file (see below)
	o NB_SPECT: 	INTEGER	Number of spectra
	o NB_POINT: 	INTEGER	Number of spectral points
	o NB_CHANN: 	INTEGER	Number of channels
	o NB_BLOCK: 	INTEGER	Number of blocks for one spectrum
	o SIZE_BL: 	INTEGER	Size of a block (see below)
	o OBSTYPE: 	STRING	Type of observation
	o BEGINS: 	STRING	UTC time of the first record of the observation,
				format=YYYY-MM-DDThh:mm:ss.ms
	o ENDS: 	STRING	UTC time of the last record of the observation,
				format=YYYY-MM-DDThh:mm:ss.ms     
      
  - "Parameters" sub-structure containing functional parameters of the
  		 instrument during the observation:
	o UVON		BOOLEAN	UV channel indicator  always 1
	o SOIR_ON	INTEGER	SOIR channel indicator - always 0 for SPICAM
	o EXIT		BOOLEAN	Flight (1) or lab (0) mode
	o DETS 		BOOLEAN Detectors used for spectrum measurement:
			0-detector 1 only; 1- detector 2 only; 
			2  both detectors;3  AOTF RF power at both DC channels
	o SOURCE	BOOLEAN	Host command is (0) or not (1) executed
	o TIME		FLOAT	AOTF chopping period 
	o GAIN		INTEGER	Amplifiers gain factor
	o GAINBST	FLOAT	The gain of amplification stage; only for SPICAV
	o DAC		INTEGER	AOTF RF power control
	o PELTIER	BOOLEAN	Peltier code indicator
	o DOTS		INTEGER	Number of predefined set of spectrum dots. 
				The set recorded after windows.
	o NDOTS		INTEGER	Total number of spectral points within DOTS  	
	
	o FREQUENCY	FLOAT ARRAY Vector of AOTF frequencies
				    size:[NB_POINTS] kHz
	o T_D0		FLOAT ARRAY Vector of Detector 0 temperature for the 
				    beginning of each spectrum
				    size:[NB_SPECT] Volts
	o T_D1		FLOAT ARRAY Vector of Detector 1 temperature for the 
				    beginning of each spectrum
				    size:[NB_SPECT] Volts
	o T_AOTF	FLOAT ARRAY Vector of AOTF temperature for the beginning
				    of each spectrum
				    size:[NB_SPECT] (not valid for SPICAV)Kelvin
	o T_BASE	FLOAT ARRAY Vector of base plate temperature for the 
				    beginning of each spectrum
				    size:[NB_SPECT] (not valid for SPICAV)Kelvin
	o POWER_RF	FLOAT ARRAY Vector of RF power at 110MHz 
				    (middle of AOTF frequency range), 
				    DAC Value is determined by command
				    size:[NB_SPECT] Volts
	o PVS		FLOAT ARRAY Vector of the supply voltage control
				    size:[NB_SPECT] Volts	
      
  - "GeoInfo" sub-structure containing geometrical parameters 
    of the instrument which do not vary during observation:
	o Target	STRING Pointing target of the instrument. Cf SPICAM/V 
			       documentation for the star catalog.
	o SunLat	FLOAT Sun latitude planet body-fixed frame, at 
			      first record (deg)
	o SunLongt	FLOAT Sun longitude planet body-fixed frame, at
			      first record (deg)
	o SunDistt	LONG  Distance between planet and sun, at first
			      record (ua)
	o SunLSt	FLOAT Sun solar longitude in the planet body-fixed
			      frame, at first record (deg)
	o SunRat	FLOAT Sun Ra, at first record (deg)
	o SunDect	FLOAT Sun Dec, at first record (deg)
	o SlitCentert	FLOAT Position vector of the slit center in SC axes 
			      (=offset, deg)
	o IRSHIFTt	FLOAT Position vector of the slit center in SC axes 

  - "Geo" sub-structure containing the time, and geometrical
    parameters which vary during observation. Parameters are
    grouped by the following nested structure.
        o Record: 
        + Number	INTEGER observation record number, beginning at 1.
        + Time		STRING	Record time, format=YYYY-MM-DDTHH:MM:SS.mSmSmS
     
	o Spacecraft: 
	+ Lat		FLOAT Latitude of the SC (deg)
        + Long		FLOAT Longitude of the SC (deg)
        + Alt		FLOAT Altitude of the SC in (km)
        + SZA		FLOAT Solar zenith angle of the SC (deg)

	o Band3: 
	+ Sza			FLOAT Solar zenith angle of the 3rd band/central 
				      line of the CCD portion (deg)
	+ DistToPlanetNP	FLOAT Distance to the planet nearest point (km)
	+ PixelSize		FLOAT Pixel size at planet nearest point (km)
	+ AngleLOSSun		FLOAT Angle between line of sight and sun (deg)
	+ PhaseLOSSun		FLOAT Phase between line of sight at planet 
				      nearest point and sun(deg)
	+ SolarIncidence	FLOAT Solar incidence between normal at planet 
				      nearest point and sun (deg)
	+ SolarLocalTime	FLOAT Solar local time at planet nearest point 
	                              (deg)
	+ AngleNormalObserver	FLOAT Angle between Normal and Observer (deg).
	+ DistLOSPlanetCenter	FLOAT Distance between line of sight and planet 
				      center (km)
       
	o IRFOV:
	+ Lat 		FLOAT Latitude of the 3rd Band  (deg)             
	+ Long 		FLOAT Longitude of the 3rd Band (deg)              
	+ Alt 		FLOAT Altitude of the 3rd Band (km)               
	+ Ra 		FLOAT Ra of the 3rd Band  (deg)   
	+ Dec 		FLOAT Dec of the 3rd Band (deg)

	o Coordinates: 
	+ Xsc_X		FLOAT X coordinate of the SC X-axis in MARSIAU/IAU_VENUS
        + Xsc_Y		FLOAT Y coordinate of the SC X-axis in MARSIAU/IAU_VENUS
        + Xsc_Z		FLOAT Z coordinate of the SC X-axis in MARSIAU/IAU_VENUS
        + Ysc_X		FLOAT X coordinate of the SC Y-axis in MARSIAU/IAU_VENUS
        + Ysc_Y		FLOAT Y coordinate of the SC Y-axis in MARSIAU/IAU_VENUS
        + Ysc_Z		FLOAT Z coordinate of the SC Y-axis in MARSIAU/IAU_VENUS
        + Zsc_X		FLOAT X coordinate of the SC Z-axis in MARSIAU/IAU_VENUS
        + Zsc_Y		FLOAT Y coordinate of the SC Z-axis in MARSIAU/IAU_VENUS
        + Zsc_Z		FLOAT Z coordinate of the SC Z-axis in MARSIAU/IAU_VENUS
        + Angle_Xsc_LocalVert	FLOAT Angle between Xsc and local vertical at 
        			      planet nearest point (deg).
        + Angle_Xsc_Proj	FLOAT Angle between Xsc and the projection plan 
        			     (PP) U-axis (deg)
        + P1_u		FLOAT U coordinate of the horizon point in the PP
        + P1_v		FLOAT Vcoordinate of the horizon point in the PP
        + P2_u		FLOAT Ucoordinate of the horizon point in the PP
        + P2_v		FLOAT V coordinate of the horizon point in the PP
        + P3_u		FLOAT U coordinate of the horizon point in the PP
        + P3_v		FLOAT V coordinate of the horizon point in the PP
        + P4_u		FLOAT U coordinate of the horizon point in the PP
        + P4_v		FLOAT V coordinate of the horizon point in the PP
        + P5_u		FLOAT U coordinate of the horizon point in the PP
        + P5_v		FLOAT V coordinate of the horizon point in the PP

	o TransMatrix: 
	+ X_Ra		FLOAT Ra of the MARSIAU/IAU_VENUS to EMEJ2000 
			      transformation matrix X vector (deg)
        + X_Dec		FLOAT Dec of the MARSIAU/IAU_VENUS to EMEJ2000
        		      transformation matrix X vector (deg)
        + Y_Ra		FLOAT Ra of the MARSIAU/IAU_VENUS to EMEJ2000
        		      transformation matrix Y vector (deg)
        + Y_Dec		FLOAT Dec of the MARSIAU/IAU_VENUS to EMEJ2000
        		      transformation matrix Y vector (deg)
        + Z_Ra		FLOAT Ra of the MARSIAU/IAU_VENUS to EMEJ2000
        		      transformation matrix Z vector (deg)
        + Z_Dec		FLOAT Dec of the MARSIAU/IAU_VENUS to EMEJ2000
        		      transformation matrix Z vector (deg)
				       
================================================================================

--------------------------------------------------------------------------------
Nicolas Chapron
CNRS | LATMOS - Laboratoire Atmospheres, Milieux, Observations Spatiales.
11 boulevard d'Alembert
78280 Guyancourt
France
Tel. 33-(0) 1 80 28 50 57
Email. nicolas.chapron@latmos.ipsl.fr
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