About SSP Data

1. Organization

  • The SSP archive consists of a single volume data set.

  • The archive volume contains the raw and calibration data from the SSP acquired during the descent phase of the Huygens Probe as well as on the surface. It also includes housekeeping data and instrument documentation.


2. Directory and File Naming


The SSP archive data volume contains the following directories:

  • CALIB - The calibration directory contains the information necessary to convert the raw SSP data to physically meaningful quantities.

  • CATALOG - The catalog directory contains general information about the data set, including information about the instrument, personnel involved, and references.

  • DATA - The data directory contains the raw data in subdirectories for each of the nine sensors that comprise SSP: Accelerometer External (ACCE), Accelerometer Internal (ACCI), Acoustic Properties Instrument - Sonar (APIS), Acoustic Properties Instrument - Velocimeter (APIV), Density Sensor (DEN), Permittivity Sensor (PER), Refractive Index Sensor (REF), Thermal Properties Sensor (THP), and Tiltmeter (TIL). In addition, it contains subdirectories for housekeeping data (HK) and the impact event (IMPACT), which included several of the sensors.

  • DOCUMENT - The documentation directory contains important SSP documents and reference publications. See below for more details.

  • INDEX - The index directory contains the archive index for the entire data volume.


There is no software provided with the SSP dataset. The data are in ASCII table format and are readable by a variety of plotting software packages.



The SSP data files follow the naming convention:



  • The SENSOR field refers to the name of the sensor (one of the nine described above) used to acquire the data.

  • The MODE represents the SSP mode as defined in the on-board Software Users Manual (see SSP_SUM.* in the DOCUMENT directory).

  • The ID is the data type identifier as defined in the on-board Software Users Manual.

  • The DATA PROCESSING LEVEL field is either "R" for raw or "C" for calibrated.

  • The SPEC field gives additional information concerning the mission phase or laboratory conditions.


More details about the file naming convention can be found in the EAICD (see below).


3. Documentation

  • Users are strongly encouraged to review the SSP AAREADME.TXT file. This file appears in the root directory of the SSP volume.

  • Further details of the SSP archive volume can be found in the "Experimenter to Archive Interface Control Document" (EACID) Document, which is found in the DOCUMENT directory on the data volume.

  • Additional references that provide detailed descriptions of the instrument and calibration process can be found in the DOCUMENT directory on the data volume.

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