PDS_VERSION_ID = PDS3 
RECORD_TYPE = FIXED_LENGTH 
RECORD_BYTES = 80 
OBJECT = TEXT 
   PUBLICATION_DATE = 2011-02-03 
   NOTE = "Description of the EXTRAS directory 
   contents for the HUYGENS DTWG data set" 
END_OBJECT = TEXT 
END 

The EXTRAS directory contains three folders:

1) INPUT_FILES:

This folder describes the input files (ZIP file) used by the DTWG tool (v5.1) for 
the computation of the Huygens trajectory DTWG#5. The filenaming and the format 
are explained in the document "EXPERIMENTER_TO_DTWG_ICD".

The list of files is:

HASI_XSERVO_CONING.DAT_PP         HASI Servo acc measurements (smoothed)
HASI_XPIEZO_04022005.DAT_PP       HASI X-Piezo accelerometer measurements
HASI_YPIEZO_04022005.DAT_PP       HASI Y-Piezo accelerometer measurements 
HASI_ZPIEZO_04022005.DAT_PP       HASI Z-Piezo accelerometer measurements

HASI_TEM_CORR_08012007.DAT_PP     HASI temperature measurements
HASI_PPI_CORR_08012007.DAT_PP     HASI pressure measurements


GCMS_MOLFRACT_N2_04052005.DAT_PP    GCMS N2 mole fraction measurements
GCMS_MOLFRACT_CH4_04052005.DAT_PP   GCMS CH4 mole fraction measurements

SSP_APIS_25082005.DAT_PP             SSP Accoustic Sounder Measurements
SSP_ACCI_IMPACT_15012005.DAT_PP      SSP Impact epoch measurement

DWE_ZWIND_27032006.DAT_PP   DWE zonal wind measurements
HK_RAU1_20052005.DAT_PP     Radar Altimeter Unit 1 (not used for reconstruction)
HK_RAU2_20052005.DAT_PP     Radar Altimeter Unit 2 (not used for reconstruction)
HK_CASU_16012005.DAT_PP     Central Accelerometer Unit measurements
HASI_PIEZO_IMPACT_05052005.DAT_PP  Impact time from HASI piezo accelerometer
DISR_WIND_27032006.DAT  Image derived DISR probe drift measurements

DISR_CORR1.DAT_PP: DISR correction in deg (in W longitude and latitude) as specified 
                   by [KARKOSCHKA2007] Table 4.
DISR_CORR2.DAT_PP: DISR correction in deg (in W longitude and latitude) as specified 
                   by [KARKOSCHKA2007] Table 5.
               
Remarks:

- all files contain 5 columns, with the following structure

  Column1: measurement epoch in ET seconds past J2000
  Column2: measurement value
  Column3: 1-sigma uncertainty of measurement value
  Column4: Integer Flag (not available for DISR_CORR1.DAT_PP)
  Column5: Integer Flag (not available for DISR_CORR2.DAT_PP)

 - The following units are used in the input files:
   
   [m/s^2] for all acclerometer measurements
   [km] for all altitude measurements
   [K] for temperature measurement
   [%] for mole fraction measurement
   [m/s] for wind measurements 
   
  
2) DTWG_SOFTWARE (v5.1):

This folder contains a ZIP file with all the FORTRAN90 source code routines
of DTWG Tool Version 5.1. Note that the current version uses Windows libraries 
for the implemented GUI and can therefore not be compiled in Unix/Linux. 
No readme file is included.

3) BSP_FILE:

This folder contains the following files:

- 050214_PE_DE405.BSP

This is a NAIF binary file containing the ephemerides of solar system planets.

- SAT199.BSP

This is a NAIF binary file containing the ephemerides of the satellites of the 
Saturnian system.

- SAT199.CMT

This is a text file describing the exact content of SAT199.BSP.