Planetary and Space Sciences Research Institute (PSSRI) Huygens-SSP Experimenter to Archive Interface Control Document PY-SSP-OU-PR-100-00 Issue 2 Rev 5 30 Nov-06 ___________________________ Prepared by: Axel Hagermann __________________________ and Brijen Hathi ___________________________ Approved by: John C. Zarnecki This page left blank Distribution List Recipient Organisation Copiest Olivier Witasse RSSD, ESTEC 1 Joe Zender RSSD, ESTEC 1 Lyle Huber PDS 1 John Zarnecki PSSRI, Open University 1 Mark Leese PSSRI, Open University 1 Change Log Date Sections Affected Changes 25/05/03, First draft First draft 30/11/2006, Issue 1.0 All Input from OW, LH 06/12/2004 0 'open issues' removed 06/12/2004 3.1 File naming convention & dir structure: 'IMPACT' added, 06/12/2004 1.7 Addresses updated 06/12/2004 1.2 List of contents inserted 06/12/2004 3.2 Time description changed 06/12/2004 All Typo in FORTRAN removed 25/07/2005 1, 2 Reference list updated 25/07/2005 All Sensor sequence harmonised 25/07/2005 2 'Tbc' removed 26/07/2005 2.3. APIS description reviewed 26/07/2005 3 Tables 3,4 amended, housekeeping description added Change log contd. Date Sections Affected Changes 26/07/2005 3.4 Directory structure updated 27/07-01/08/2005 4.2 Labels updated 01/08/2005 4.2 Table removed 01/08/2005 4.3 Section added, objects amended 01/08/2005 Appendix Obsolete appendix removed 01/08/2005 2.3 Functional table added 31/10/05 3.4.3 'tbc' removed 17/11/05 2.2 Table 1 amended 21/11/05 3.4.3 superseded in parts 21/02/05 4 Sample labels & object definitions updated 01/03/05 3.4 Table 4 amended 04/07/06 All Typos corrected 04/07/06 2 & 3 Review info added 01/10/06 Acronyms and Abbreviations ACC-E - Accelerometer / Force Transducer (External) sub-system ACC-I - Accelerometer (Internal) sub-system APIS - Acoustic sounder sub-system APIV - Acoustic velocity sub-system DDID - ESOC's Data Delivery Interface Document DEN - Density sub-system DL - PDS term 'Detached Label' DN - A/D converters output in 'counts' (PDS term = Digital Number) DTWG - Descent trajectory working group EAICD - Experimenter to (Science) Archive Interface Control Document ESA - European Space Agency ESOC - European Space Operations Centre HK - Housekeeping data NASA - National Aeronautics and Space Administration PDD - Parachute deployment device PDS - Planetary Data System PER - Relative permittivity and conductivity sub-system PSA - Planetary Science Archive PSSRI - Planetary and Space Sciences Research Institute SSP - Surface Science Package REF - Refractive index sub-system TBC - to be confirmed TBD - to be determined TBW - to be written THP - Thermal properties sub-system TIL - 2 axis tilt angle measuring sub-system List of contents 1 INTRODUCTION 4 1.1 PURPOSE AND SCOPE 4 1.2 CONTENTS 4 1.3 INTENDED READERSHIP 4 1.4 APPLICABLE DOCUMENTS 4 1.5 REFERENCE DOCUMENTS 4 1.6 RELATIONSHIPS TO OTHER INTERFACES 5 1.7 CONTACT NAMES AND ADDRESSES 5 2 OVERVIEW OF PROCESS AND PRODUCT GENERATION 6 2.1 EXPERIMENT OVERVIEW 6 2.2 MEASUREMENTS SUMMARY 6 2.3 SENSORS OVERVIEW 7 2.3.1 Accelerometer External (ACC-E) 7 2.3.2 Accelerometer Internal (ACC-I) 7 2.3.3 Acoustic Properties Instrument - Sonar (API-S) 7 2.3.4 Acoustic Properties Instrument - Velocimeter (API-V) 8 2.3.5 Density Sensor (DEN) 8 2.3.6 Permittivity Sensor (PER) 8 2.3.7 Refractive Index Sensor (REF) 9 2.3.8 Thermal Properties Sensor (THP) 9 2.3.9 Tiltmeter (TIL) 9 2.4 DEFINITION OF SSP OPERATING MODES 10 3 ARCHIVE FORMAT AND CONTENT 11 3.1 FORMAT AND CONVENTIONS 11 3.1.1 Deliveries and Archive Volume Format 11 3.1.2 Data Set ID Formation 11 3.1.3 Data Directory Naming Convention 12 3.1.4 File naming Convention 12 3.2 STANDARDS USED IN DATA PRODUCT GENERATION 12 3.2.1 PDS Standards 12 3.2.2 Time Standards 12 3.2.3 Reference Systems 12 3.2.4 Other Applicable Standards 13 3.3 DATA VALIDATION 13 3.4 CONTENT 13 3.4.1 Volume Set 13 3.4.2 Data Set 13 3.4.3 Directories 14 3.4.4 Derived and other Data Products 16 4 DETAILED INTERFACE SPECIFICATIONS 17 4.1 DATA PRODUCT DESIGN 17 4.2 SAMPLE LABELS 17 4.2.1 ACCE - Data Label 1 17 4.2.2 ACCE - Data Label 2 17 4.2.3 ACCI - Data Label 1 18 4.2.4 ACCI - Data Label 2 19 4.2.5 APIS - Data Label 1 20 4.2.6 APIS - Data Label 2 20 4.2.7 APIS - Data Label 3 21 4.2.8 APIV - Data Label 21 4.2.9 DEN Data Label 22 4.2.10 HK - Data Label 22 4.2.11 IMPACT Data Label 23 4.2.12 PER Data Label 24 4.2.13 REF Data Label 24 4.2.14 THP - Data Label 25 4.2.15 TIL Data Label 25 4.3 DATA PRODUCT DESIGN 27 4.3.1 Data Product Design Example - ACCE Sensor 27 4.3.2 Data Object Definition Example - ACCI sensor 29 4.3.3 Data Product Design - APIS Sensor 32 4.3.4 Data Product design, DEN, HK, PER, THP, TIL 32 4.3.5 Data Product Design - REF Sensor 32 5 APPENDIX: AVAILABLE SOFTWARE TO READ PDS FILES 34 6 APPENDIX: AUXILIARY DATA USAGE 35 7 APPENDIX: EXAMPLE OF DIRECTORY LISTING OF DATA SET 36 1 Introduction 1.1 Purpose and Scope The primary objective of this EAICD document is to provide a detailed explanation of the SSP data ingested into the PSA. It describes data flow, data types and directory structures for data volumes. The secondary objective of this document is to provide a formal interface for communication between SSP PI and the archiving authority. The methods used for interpreting SSP data any further than given in the archive or a detailed description of the SSP experiment is beyond the scope of this document. Please refer to reference section for some further details. 1.2 Contents This document describes the SSP data as presented to the PDS data archive. It includes information on how the data is processed, formatted, labelled and uniquely identified. The document discusses general naming schemes for data volumes, data sets, data and label files. Standards used to generate the product are explained. The design of the data set structure and the data product is given. Examples of these are given in the appendix. 1.3 Intended Readership The staff of archiving authority (Planetary Data System for NASA, Planetary Science Archive for ESA) design team and any potential user of the SSP final archive. 1.4 Applicable Documents [AD-1] Planetary Data System Preparation Workbook, February 1, 1995, Version 3.1, JPL, D-7669, Part 1 [AD-2] Planetary Data System Standards Reference, October 30, 2002, Version 3.5, JPL, D-7669, Part 2 [AD-3] PY-SSP-RAL-xxxx, Huygens Surface Science Package, On-board Software Users Guide, Issue 2, August 2004. [AD-4] HMCS-ICD-DDID, Huygens DDID, Data Delivery Interface Document, Issue 2.1, September 1996. [AD-5] PY-SSP-UKC-EID-001, SSP-EID-B, Experiment Interface Control Document, 23 February 1995 [AD-6] HUY-RSSD-PL-001, Huygens Data Archive Generation, Validation and Transfer Plan DRAFT, 1September 2004. 1.5 Reference Documents [RD-1] J.C. Zarnecki, M.R. Leese, J.R.C. Garry, N. Ghafoor and B. Hathi (2002): HUYGENS' SURFACE SCIENCE PACKAGE.. Space Science Reviews, Vol. 104(1), p. 591-609 [RD-2] English, M.A., (1995): The development of instrumentation and modelling for the understanding of Titan. PhD thesis, University of Kent at Canterbury. [RD-3] Geake, J. E., Mill, C. and Mohammadi, M.S.: 1994, Meas. Sci. Technol. 5, 531. [RD-4] J. C. Zarnecki and M. Banaszkiewicz, M. Bannister, W. V. Boynton, P. Challenor, B. Clark, P. M. Daniell, J. Delderfield, M. A. English, M. Fulchignoni, J. R. C. Garry, J. E. Geake, S. F. Green, B. Hathi, S. Jaroslawski, M. R. Leese, R. D. Lorenz, J. A. M. McDonnell, N. Merryweather--Clarke, C. S. Mill, R. J. Miller, D. J. Parker, P. Rabbetts, H. Svedhem, R. F. Turner, M. J. Wright (1997): The Huygens Surface Science Package, ESA SP-1177, 177-195. [RD-5] M. K. Bird, M. Heyl, M. Allison, S.W. Asmar, D.H> Atkinson, P. Edenhofer, D. Plettemeier, R. Wohlmuth, L. Iess & GlL. Tyler (1997) The Huygens Doppler Wind Experiment, ESA SP-1177, 139-162. [RD-6] R. Lorenz (1994): Exploring the surface of Titan. Dissertation, University of Kent, Canterbury. [RD-7] A. Wilson (ed.)(1997): Huygens - Science, Payload and Mission. ESA SP-1177. 1.6 Relationships to Other Interfaces N/A 1.7 Contact Names and Addresses Axel Hagermann The Open University Walton Hall, Milton Keynes MK7 6AA United Kingdom a.hagermann@open.ac.uk Brijen Hathi The Open University Walton Hall, Milton Keynes MK7 6AA United Kingdom b.hathi@open.ac.uk Mark Leese The Open University Walton Hall, Milton Keynes MK7 6AA United Kingdom m.r.leese@open.ac.uk John Zarnecki The Open University Walton Hall, Milton Keynes MK7 6AA United Kingdom j.c.zarnecki@open.ac.uk 2 Overview of Process and Product Generation Huygens SSP data will be analysed at the PSSRI at the Open University. Descent data are provided by ESOC (see [AD-4]). Further data include those of calibrations, carried out mainly at the Open University, the University of Kent at Canterbury and other Institutions (See [AD-5] for details). Data types are grouped into Science data and calibration data. All data will be ingested into the PSA in compliance with [AD-6]. The process of data analysis as described in this document includes the extraction of SSP packet data from Huygens telemetry packets provided by ESOC, seperation into the packets from the individual SSP sensors and extraction into human-readable (PDS-compliant) format. Data are processed using custom software written in FORTRAN, PYTHON and IDL. 2.1 Experiment Overview The SSP experiment consists of nine separate sensors that are designed to measure a wide range of physical properties of Titan's lower atmosphere, surface, and sub-surface. By measuring a number of physical properties of the surface it is expected that the SSP will be able to constrain the inferred composition and structure of the Titan's near-surface environment. Although the SSP is primarily designed to sense properties of the surface, some of its sensors will also make measurements of the atmosphere along the probe's entry path and will complement the data gathered by other experiments on the Huygens probe. 2.2 Measurements Summary Table 1 (below) summarises the measurements made by the SSP experiment. sensor Measured parameters Derived parameters ACC-E Impact force Impact force ACC-I Acceleration Acceleration API-S Acoustic excitation Sounding information API-V Time delay in milli seconds Speed of sound and Mean molecular mass DEN Strain (of buoyancy float) Density PER Capacitance Permittivity and conductivity REF Light intensities Refractive index THP Resistance Temperature and thermal conductivity TIL 2-axis tilt angles Tilt angles HK Temperatures, and other engineering information Temperatures, and other engineering information Table 1: SSP experiment - measured and derived parameters summary The housekeeping sensors (HK) give information about sensor temperatures, times of mode changes, software glitches, packet counts and other relevant data. Details can be found in [AD-3]. 2.3 Sensors Overview The following listing of the SSP sensors consists mainly of excerpts from RD-1 which should be consulted for more detailed information. 2.3.1 Accelerometer External (ACC-E) The accelerometer subsystem is designed to characterise the immediate surface of the landing site by recording the dynamic response of two devices mounted in different positions on the probe. One of the sensors, discussed by in [RD-6] is designed to sense the force exerted on a pylon that protrudes from the foredome aperture. The force is sensed by a piezoelectric ceramic element that is mounted between a hemispherical titanium alloy head and the pylon shaft. If Huygens lands on a relatively uniform surface the ACC-E penetrometer will be smoothly driven into the surface material until the probe's fore-dome strikes the surface, bringing it to a halt. During the impact process the ACC-E is sampled at a rate of 10 kHz, giving it an effective depth resolution of 1 mm for a nominal mission impact speed of 5 m s-1. 2.3.2 Accelerometer Internal (ACC-I) A single commercially available accelerometer forms the second part of the ACC sensor. This device is mounted on a foot of the SSP electronics box, which is fixed to the upper experiment platform. The ACC-I provides information about the vertical non-static accelerations experienced by the entire probe. 2.3.3 Acoustic Properties Instrument - Sonar (API-S) Like the ACC subsystem, the API has two separate parts. The first of these is an active sonar system (API-Sonar) mounted on the front of the Top Hat cavity pointing downwards. This sensor will measure the effective acoustic cross-section of the medium within its field of view at a frequency of around 15kHz. Each echo is sampled at a rate of 1kHz, and during the final section of the probe's descent this sensor may be able to provide information about the topography of the landing site with a vertical precision of around 0.1 m. In the case of a liquid touchdown the API-S may also be able to provide lower bounds to the depth of the liquid in which it has landed. In the final few hundred metres of Huygens' trajectory the API-S will be sufficiently close to the surface for it to detect the back-scattered echo from the surface beneath it. Following the impact of the probe with a liquid body the API-S will act as a depth sounder, using information gathered from the Acoustic Properties Instrument-Velocimeter (API-V) on the speed of sound in the medium. In comparison to its atmospheric operation the API-S operates with an increased efficiency when immersed simply as a result of the medium's higher density and its better acoustic coupling to the API-S. Whilst afloat the API-S should be able to record the depth of the liquid beneath the probe (up to a maximum depth of 1000m). 2.3.4 Acoustic Properties Instrument - Velocimeter (API-V) The second portion of the API consists of a pair of piezoelectric transducers mounted at the front surface of the Top Hat on either side of the cavity. These sensors measure the speed of sound by transmitting, and subsequently receiving, a brief 1 MHz acoustic signal. The time interval between transmission and reception is measured with a precision of 250 ns and the separation of 0.125 m gives a speed resolution of 8 cm s-1 when operating in gas at Titan's surface. Throughout the descent these sensors will be driven and subsequently sampled once a second, giving a detailed profile of the speed of sound along the probe's trajectory. At least three other sensors in the probe's payload can sense the atmospheric temperature, and thus the speed of sound will yield the ratio of gamma (the ratio of specific heats) to m (mean molecular mass). The next important contribution made by the API-V is at Titan's surface in the event of the probe landing in a liquid body. The speed of sound is measured to a precision of 8 m s-1, a fidelity that corresponds to a mixing ratio of 1.6 % for a methane / ethane ocean. 2.3.5 Density Sensor (DEN) Upon landing in a liquid the density of any fluid that makes its way into the cavity of the SSP will be estimated by the DEN sensor. This instrument measures the upthrust applied by a liquid to a small buoyant float which is attached to the SSP by a pair of epoxy beams that are equipped with strain gauges [RD-2]. In addition considerable scope remains for the detection of phenomena that are secondary to the main role of the SSP. For example, immediately following the probe's impact with a liquid the DEN may detect the periodic inflow and outflow of fluid from the SSP cavity. Measurements of the rate at which this bobbing motion decays will place constraints on the viscosity of the impacted liquid, a property that is not directly measured by any sensor. 2.3.6 Permittivity Sensor (PER) In the event of a liquid landing the SSP will also be able to determine a number of electrical properties of the fluid. The PER device consists of 22 stacked parallel plates, the capacitance of which is measured at a number of different frequencies. By briefly pulsing the sensor with DC voltages the conductivity of the surrounding liquid may also be ascertained, placing constraints on the population of dissolved ions (if any) in the medium. The PER also carries a thermometer in the form of a silicon diode, which has a precision of better than 0.5 K. Although any probable Titan atmosphere has a relative permittivity that is almost identical to 1, and therefore cannot be detected by PER, at the tropopause (altitude 40 km) significant quantities of methane/nitrogen may condense temporarily on the PER sensor. If sufficient material collects on the PER some or all of the sensing plates may be bridged and the condensate may thus be detected. 2.3.7 Refractive Index Sensor (REF) The REF sensor measures the refractive index of a liquid by using a linear critical angle refractometer, the method and design of which is discussed in [RD-3]. This device consists of a section of a cylindrical prism that can be illuminated by collimated sources (light guides fed by light emitting diodes, LEDs, at 635 nm) that are both internal and external to the prism. When the REF is immersed in a medium of given refractive index light striking the interface between the prism and the liquid will experience a critical angle effect, in which case the light is refracted or reflected. For both the internal and external illumination only part of the beam is reflected or refracted onto the detector, the remainder escaping or being reflected from the prism. A 512 element linear photodiode array is attached to one face of the prism and this array is used to measure the resulting transition from light to dark, the position of this transition, or cut-off, being linearly related to the refractive index of the liquid. The sensor covers the refractive index range 1.250 to 1.450 with a discrimination of 0.001. The external light source is provided so that an estimate can be made of the opacity of the ambient liquid, from a comparison of the illumination profile received from the internal and external sources. 2.3.8 Thermal Properties Sensor (THP) The main role of the THP is to measure the thermal conductivity and diffusivity of the ambient medium in the SSP cavity. Along with the Acoustic Properties Instrument (API), the THP is designed to sense properties of both liquid and gaseous media, using two separate sets of redundant hot wire sensors enclosed in cylindrical shields. By applying a known current for a fixed duration to the THP's sense wires in each of the four cylindrical canisters the wires are made to act as regulated heat sources. This method is covered in detail by Healy et al. (1976). In the close confines of the wires' shields the transient heat pulse thus generated is lost by conduction to the medium surrounding the wires at a rate that is determined by the thermal properties of the material. Measurements of the wires' resistance as a function of time before and after the heating pulse reveal the initial temperature of the medium and its thermal properties. Two diameters of platinum wire are used in the THP, the thinner wires (10 m diameter) are sized for the relatively low thermal conductivity of the atmosphere, and the thicker 25 m diameter wires are only driven when the Huygens probe has reached the surface. A THP measurement is made every minute throughout the atmospheric phase of the descent and will therefore provide a relatively fine record of the thermal properties of the atmosphere along Huygens' trajectory. 2.3.9 Tiltmeter (TIL) One of the important analyses to be carried out after arrival at Titan is the reconstruction of the probe's motion, i.e. its trajectory, attitude, swing and spin, as it falls through the atmosphere and then subsequently during any post-impact dynamics. Throughout Huygens' descent particular aspects of the probe's motion will be measured with varying precision by three separate experiments, Doppler Wind Experiment [RD-5], Huygens Atmospheric Structure Instrument (HASI), and SSP. Of these, TIL is the only device that provides unambiguous information about the Huygens probe's attitude with respect to the local vertical rather than its acceleration. Two inclinometers are arranged to form an orthogonal x-y pair inside the sensor housing which is attached to the SSP electronics box. During the probe's descent the TIL is sampled at a rate of 1 Hz. 2.4 Definition of SSP Operating Modes The SSP operating modes are defined as follows: M0: Checkout / Diagnostic mode - not used during the real descent M1: upper atmosphere mode M2: mid atmosphere mode M3: lower atmosphere mode M4: proximity mode M5: surface mode M6: extended surface mode M7: Checkout / Diagnostic mode - not used during the real descent A functional breakdown of SSP's sensors is given in Table 1. Atmospheric Modes Surface Modes Atmospheric Modes Surface Modes SENSOR SSP Mode 1 Upper Atmosphere SSP Mode 2 Mid Atmosphere SSP Mode 3 Lower Atmosphere SSP Mode 4 Proximity Mode SSP Mode 5 Post Impact SSP Mode 6 Extended Surface Mission ACC-I Sampled at 1Hz Sampled at 1Hz Sampled at 1Hz Monitor ACC-I Impact Buffer Readout ACC-I Impact Buffer Sampled at 1Hz ACC-E Monitor ACC-E Impact Buffer Readout ACC-E Impact Buffer REF Internal, external modes and dark scan every 3 minutes Single set of scans Internal, external modes and dark scan every 3 minutes THP Sampling in atmospheric mode Sampling in surface mode API-V Sampled at 1Hz (in alternate directions) API-S Sample in Atmospheric Mode Proximity Mode Sample in Surface Mode DEN Sampled at 1Hz throughout Modes 1 to 6 TIL 2 axes at 1Hz sampling rate 2 axes at 2Hz sampling rate PER Table 1 Functional breakdown of SSP sensors 3 Archive Format and Content 3.1 Format and Conventions 3.1.1 Deliveries and Archive Volume Format The individual logical archive volumes delivered always contain " the data from ALL sensors " the raw data, calibrated data and the calibration data and software The logical archive volumes will contain one data set per volume. 2 logical archive volumes were identified: " Descent data " Selected laboratory data The descent dataset contains all data necessary for an analysis the SSP measurements. Laboratory data will be added on a best effort basis, provided they are considered helpful in the analysis. The SSP sensor housekeeping data and the SSP status data will always be archived similar to other sensor data within the appropriate data sets. 3.1.2 Data Set ID Formation The following data sets are foreseen: " HP-SSA-SSP-3-DESCENT-V1.0 3.1.3 Data Directory Naming Convention For all data sets the following directory naming scheme will be used: /DATA/{type}/{dpl}/{sensor}/filename, with " type = {DESCENT} " dpl = {RAW, CALIBRATED}, with dpl standing for data processing level " sensor = {ACCI, ACCE, APIS, APIV, DEN, HK, IMPACT, PER, REF, THP, TIL, STATUS} The calibration data will be archived in the CALIB directory below the root directory, as " /CALIB/SSP_CAL.ASC 3.1.4 File naming Convention The following file naming scheme will be used for all data sets: SSP_{sensor}_{mode}_{id}_{data processing level}_{spec}, with " sensor = {ACCI, ACCE, APIS, APIV, DEN, HK, IMPACT, PER, REF, THP, TIL, STATUS} " mode = {0, 1, 2, 3, 4, 5, 6, 7, 8, 123, 1236, 123456}, these modes represent the SSP mode as defined in [AD-3] " id= {0,1,2}, data type identifier as defined in [AD-3] " data processing level = {R, C}, for raw and calibrated data respectively " spec = {ATMOS, PROX, SURF, EXTD, IMPACT, METHAN, ETHAN, ….}, the specs give additional information on the mission phase or the laboratory conditions. 3.2 Standards Used in Data Product Generation 3.2.1 PDS Standards PDS Standard version 3.5 is used for the design of the SSP archive. 3.2.2 Time Standards The timing information used in all SSP data is derived from the Huygens Probe clock. This clock starts at zero (T0 as defined by the Probe's firing of the PDD) and has resolution of 2 milliseconds. The format used to represent SSP time is a REAL number consisting of seconds (integer part) and milliseconds (fractional part of the number) . Examples of the time format are given by the parameters: SC_CLOCK_START_COUNT and SC_CLOCK_STOP_COUNT. 3.2.3 Reference Systems TBD by the DTWG 3.2.4 Other Applicable Standards No other applicable standards are used. 3.3 Data Validation Science validation will be performed during data analysis. Descent data can be compared to laboratory tests. Dataset completeness will be verified manually at each revision of the dataset and reviewed before release to the public. Compliance of SSP datasets with PDS standards on structural as well as label level will be verified prior to ingestion using the PVV tool delivered by ESTEC (TBC). 3.4 Content 3.4.1 Volume Set The SSP team will aim to deliver three logical archive volumes. The volumes names and volume ids are the following (tbc): Volume Name Volume ID Data Set ID HUYGENS PROBE DESCENT SSP DATA RECORD UK_ESA_PSA_HP_1001 (tbc), as provided by PSA HP-SSA-SSP-3/4-DESCENT-V1.0 HUYGENS PROBE FLIGHT CHECK OUTS SSP DATA RECORD UK_ESA_PSA_HP_1002 (tbc), as provided by PSA HP-CRU-SSP-3/4-FLIGHT-CHECK-OUTS-V1.0 Table 2: Proposed SSP Data (or 'logical archive volumes') for PDS archive 3.4.2 Data Set Table 3 gives the definition of the data set name and data set id: Data Set ID Data Set Name HP-SSA-SSP-3/4-DESCENT-V1.0 HUYGENS SSP DESCENT RAW AND CALIBRATED DATA V1.0 Table 3: SSP Data sets description Table 4 describes the data types used for the raw data, data processing level 3 in the PDS standard. The raw data will contain the DN of the A/D converters from the individual sensors and for some of these DN, the data sets will contain the corresponding voltages in addition. DL is used to identify Detached Label. The IMPACT packets will be handled separately. For details of table sizes refer to the template labels in the next section. Sensor HP-SSA-SSP-3/4-DESCENT HP-CRU-SSP-3/4-FLIGHT-CHECK-OUTS HP-CAL-SSP-3-LABORATORY ACC-E DL + table(column,time series) 5 (impact) Same as 'HP-SSA-SSP-3/4-DESCENT' N/A DL + table(column,time series) 1,2,3 (stimulus) ACC-I DL+ table 5 Same as 'HP-SSA-SSP-3/4-DESCENT' N/A DL + table 1,2,3,5,6 API-S DL + table (mode 2,3) DL + table (mode 4,5) DL + table (mode 6) Same as 'HP-SSA-SSP-3/4-DESCENT' N/A API-V DL + table ( n x 3 ) (all modes) Same as 'HP-SSA-SSP-3/4-DESCENT' N/A DEN DL + table (all modes) Same as 'HP-SSA-SSP-3/4-DESCENT' N/A HK DL + table Same as 'HP-SSA-SSP-3/4-DESCENT' N/A IMPACT DL + table Same as 'HP-SSA-SSP-3/4-DESCENT' N/A PER Dl + table (all modes) Same as 'HP-SSA-SSP-3/4-DESCENT' N/A REF DL+ table (all modes) Same as 'HP-SSA-SSP-3/4-DESCENT' N/A STATUS DL + table (TBD) Same as 'HP-SSA-SSP-3/4-DESCENT' N/A THP DL + table Same as 'HP-SSA-SSP-3/4-DESCENT' N/A TIL DL + table Same as 'HP-SSA-SSP-3/4-DESCENT' N/A Table 4: SSP data types and presentation to the PDS archive - data processing level 3 3.4.3 Directories Directories are defined in Table 6 Top-Level Directory Structure for a SSP data volume ROOT AAREADME.TXT description of volume contents ERRATA.TXT overview of anomalies and errors VOLDESC.CAT description of the contents of the logical volume CATALOG CATINFO.TXT text description of the directory contents MISSION.CAT PDS catalog object for Mission INST.CAT brief description of the SSP Sensors INSTHOST.CAT brief description of the Instrument Host DATASET.CAT brief description of the reduced data PERSON.CAT description of key persons involved in SSP TARGET.CAT brief description of the targets of the mission REFERENCE.CAT References used in catalogue files SOFT.CAT Obsolete CALIB SSP_CAL.* Calibration file DOCUMENT DOCINFO.TXT description of the content of the Document Directory SSP_EAICD.PDF contains the SSP EAICD SSP_SUM.PDF Software user manual for SSP = [AD-3] Others [RD-4], PHD_GHAFOOR, PHD_LORENZ, …. INDEX INDEX.LBL detached PDS label to describe INDEX.TAB INDEX.TAB PDS table, listing all data files included in the volume INDXINFO.TXT N/A DATA (each data file is described in the accompanying detached PDS label) {type} RAW {sensor} {file} Data file Where " type = { DESCENT} dpl = {RAW, CALIBRATED}, sensor = {ACC, ACCE, APIS,APIV, DEN, HK, IMPACT, PER, REF, STATUS, THP, TIL} Table 6: Overview of the SSP data volume structure Root Directory CALIB Directory The calibration data will be archived in the CALIB directory below the root directory, as " /CALIB/SSP_CAL.ASC for the sensors ACC, ACCE, APIS, APIV, DEN, HK, IMPACT, PER, REF, STATUS, THP, TIL Data from the HP-CRU-SSP-3/4-FLIGHT-CHECK-OUTS data set will be provided and added to the delivery of the descent data sets on a best effort basis. The calibration information will not be updated in this data set. A note will be put in the catalog files to explicitely warn future users of this fact and point them to the calibration information that will be delivered with the descent data set that might have been updated and improved. CATALOG Directory This directory contains catalog files. INDEX directory This directory contains index files and labels. Browse Directory and Browse Files Not envisaged. Geometry Directory N/A SOFTWARE Directory N/A GAZETTER Directory N/A. Label Directory N/A DOCUMENTS Directory Will contain the documents necessary for analysing SSP data. This directory will contain at least the following documents: " On-board Software User Guide [AD-3] " EID-B [AD-5] " SP-1177, SSP [RD-4] " Publication in scientific journals The format of the documentation may vary and may be very old. Reformatting is done on a best effort basis. The conversion to ASCII format will also be done on a best effort basis. Documents that cause a format problem will be provided as they are (i.e. in pdf, TIFF or Word .doc format) in the extras directory. Important images and diagrams will be converted to PNG or JPG format. EXTRAS Directory Digital images of test equipment, sensors etc will be put on this directory. Types and sizes is TBD. DATA Directory see section 3.1.3 Pre-Flight Data The following pre-flight data are available: Pre-Flight Data Status Expected Data Volume Laboratory data Selected data will be archived TBD Campaign data Not available n/a EMC data Included in laboratory data n/a In-Flight Data In-Flight Data Status Expected Data Volume In-flight check-outs will be archived 14 * ~50Mbytes Descent trajectory Will be archived < 1MByte 3.4.4 Derived and other Data Products N/A 4 Detailed Interface Specifications Data will be received by PSSRI as described in [AD-4]. Datasets will be ingested into the PSA using the interfaces described in [AD-6]. Dataset integrity will be verified using the tools provided by ESOC (TBC). 4.1 Data Product Design Descent data products will be tables of 2 to 1129 colums, depending on the type of SSP sensor, with detached labels. Calibration data will be delivered in tables or as PDF documents. 4.2 Sample Labels Sample labels in this document are subject to revision once processing software has been completed. 4.2.1 ACCE - Data Label 1 PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 72 FILE_RECORDS = 512 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_ACCE_057_1_R_IMPACT.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_ACCE_057_1_R_IMPACT.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_ACCE_057_1_R_IMPACT.LBL" PRODUCT_CREATION_TIME = 2005-02-01T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR START_TIME = 2005-01-14T11:38:10.4600 STOP_TIME = 2005-01-14T11:38:10.5111 SPACECRAFT_CLOCK_START_COUNT = 8869.7600 SPACECRAFT_CLOCK_STOP_COUNT = 8869.8111 NATIVE_START_TIME = 8869.7600 NATIVE_STOP_TIME = 8869.8111 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.2 ACCE - Data Label 2 PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 2132 FILE_RECORDS = 3 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_ACCE_123_2_R_ATMOS.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_ACCE_123_2_R_ATMOS.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_ACCE_123_2_R_ATMOS.LBL" PRODUCT_CREATION_TIME = 2005-02-01T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR START_TIME = 2005-01-14T09:11:22.7100 STOP_TIME = 2005-01-14T10:35:20.7060 SPACECRAFT_CLOCK_START_COUNT = 62.0100 SPACECRAFT_CLOCK_STOP_COUNT = 5100.0060 NATIVE_START_TIME = 62.0100 NATIVE_STOP_TIME = 5100.0060 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.3 ACCI - Data Label 1 PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 72 FILE_RECORDS = 512 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_ACCI_057_1_R_IMPACT.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_ACCI_057_1_R_IMPACT.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_ACCI_057_1_R_IMPACT.LBL" PRODUCT_CREATION_TIME = 2005-02-07T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR /* EDR for RAW, RDR for calibrated data, tbc */ START_TIME = 2005-01-14T11:38:10.4700 STOP_TIME = 2005-01-14T11:38:11.4920 SPACECRAFT_CLOCK_START_COUNT = 8869.7700 SPACECRAFT_CLOCK_STOP_COUNT = 8870.7920 NATIVE_START_TIME = 8869.7700 NATIVE_STOP_TIME = 8870.7920 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.4 ACCI - Data Label 2 PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 1452 FILE_RECORDS = 1 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_ACCI_1_2_R_ATMOS.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_ACCI_1_2_R_ATMOS.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_ACCI_1_2_R_ATMOS.LBL" PRODUCT_CREATION_TIME = 2004-10-07T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR START_TIME = 2005-01-14T09:11:16.0000 STOP_TIME = 2005-01-14T09:11:16.0000 SPACECRAFT_CLOCK_START_COUNT = 55.3000 SPACECRAFT_CLOCK_STOP_COUNT = 55.3000 NATIVE_START_TIME = 55.3000 NATIVE_STOP_TIME = 55.3000 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" ACCI - Data Label 3 PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 102 FILE_RECORDS = 10998 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_ACCI_1236_0_R_ATMOS.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_ACCI_1236_0_R_ATMOS.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_ACCI_1236_0_R_ATMOS.LBL" PRODUCT_CREATION_TIME = 2005-02-07T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR /* EDR for RAW, RDR for calibrated data, tbc */ START_TIME = 2005-01-14T09:11:22.0440 STOP_TIME = 2005-01-14T12:47:28.5880 SPACECRAFT_CLOCK_START_COUNT = 61.3440 SPACECRAFT_CLOCK_STOP_COUNT = 13027.8880 NATIVE_START_TIME = 61.3440 NATIVE_STOP_TIME = 13027.8880 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.5 APIS - Data Label 1 PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 572 FILE_RECORDS = 4615 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_APIS_23_0_R_ATMOS.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_APIS_23_0_R_ATMOS.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_APIS_23_0_R_ATMOS.LBL" PRODUCT_CREATION_TIME = 2005-02-01T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR START_TIME = 2005-01-14T09:20:20.7860 STOP_TIME = 2005-01-14T11:10:19.5860 SPACECRAFT_CLOCK_START_COUNT = 600.0860 SPACECRAFT_CLOCK_STOP_COUNT = 7198.8860 NATIVE_START_TIME = 600.0860 NATIVE_STOP_TIME = 7198.8860 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.6 APIS - Data Label 2 PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 2772 FILE_RECORDS = 654 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_APIS_4_0_R_PROX.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_APIS_4_0_R_PROX.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_APIS_4_0_R_PROX.LBL" PRODUCT_CREATION_TIME = 2005-10-07T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR /* EDR for RAW, RDR for calibrated data, tbc */ START_TIME = 2005-01-14T11:10:20.8040 STOP_TIME = 2005-01-14T11:40:44.2180 SPACECRAFT_CLOCK_START_COUNT = 7200.1040 SPACECRAFT_CLOCK_STOP_COUNT = 9023.5180 NATIVE_START_TIME = 7200.1040 NATIVE_STOP_TIME = 9023.5180 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.7 APIS - Data Label 3 PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 12782 FILE_RECORDS = 92 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_APIS_6_0_R_EXTD.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_APIS_6_0_R_EXTD.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_APIS_6_0_R_EXTD.LBL" PRODUCT_CREATION_TIME = 2005-10-07T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR START_TIME = 2005-01-14T11:41:21.1360 STOP_TIME = 2005-01-14T12:46:26.9380 SPACECRAFT_CLOCK_START_COUNT = 9060.4360 SPACECRAFT_CLOCK_STOP_COUNT = 12966.2380 NATIVE_START_TIME = 9060.4360 NATIVE_STOP_TIME = 12966.2380 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.8 APIV - Data Label PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 82 FILE_RECORDS = 12132 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_APIV_123456_0_R_ATMOS.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_APIV_123456_0_R_ATMOS.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "HP-SSP-DEN-M123456-R.LBL" PRODUCT_CREATION_TIME = 2005-02-01T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR START_TIME = 2005-01-14T09:20:20.7060 STOP_TIME = 2005-01-14T12:47:09.2600 SPACECRAFT_CLOCK_START_COUNT = 600.0060 SPACECRAFT_CLOCK_STOP_COUNT = 13008.5600 NATIVE_START_TIME = 600.0060 NATIVE_STOP_TIME = 13008.5600 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.9 DEN Data Label PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 72 FILE_RECORDS = 12640 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_DEN_123456_0_R_ATMOS.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_DEN_123456_0_R_ATMOS.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_DEN_123456_0_R_ATMOS.LBL" PRODUCT_CREATION_TIME = 2005-02-01T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR START_TIME = 2005-01-14T09:11:21.4840 STOP_TIME = 2005-01-14T12:46:33.0760 SPACECRAFT_CLOCK_START_COUNT = 60.7840 SPACECRAFT_CLOCK_STOP_COUNT = 12972.3760 NATIVE_START_TIME = 60.7840 NATIVE_STOP_TIME = 12972.3760 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.10 HK - Data Label DS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 1092 FILE_RECORDS = 638 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_HK_123456_0_R_ATMOS.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_HK_123456_0_R_ATMOS.LBL" DATA_SET_ID = "HP-SSA-SSP-3-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_HK_123456_0_R_ATMOS.LBL" PRODUCT_CREATION_TIME = 2005-02-01T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR START_TIME = 2005-01-14T09:11:21.1060 STOP_TIME = 2005-01-14T12:47:46.9940 SPACECRAFT_CLOCK_START_COUNT = 60.4060 SPACECRAFT_CLOCK_STOP_COUNT = 13046.2940 NATIVE_START_TIME = 60.4060 NATIVE_STOP_TIME = 13046.2940 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.11 IMPACT Data Label PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 812 FILE_RECORDS = 8 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_IMPACT_5_0_R_SURF.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_IMPACT_5_0_R_SURF.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_IMPACT_5_0_R_SURF.LBL" PRODUCT_CREATION_TIME = 2005-02-01T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR START_TIME = 2005-01-14T11:38:10.4700 STOP_TIME = 2005-01-14T11:38:10.4700 SPACECRAFT_CLOCK_START_COUNT = 8869.7700 SPACECRAFT_CLOCK_STOP_COUNT = 8869.7700 NATIVE_START_TIME = 8869.7700 NATIVE_STOP_TIME = 8869.7700 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.12 PER Data Label PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 122 FILE_RECORDS = 1332 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_PER_123456_0_R_ATMOS.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_PER_123456_0_R_ATMOS.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_PER_123456_0_R_ATMOS.LBL" PRODUCT_CREATION_TIME = 2005-02-01T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR START_TIME = 2005-01-14T09:11:31.1380 STOP_TIME = 2005-01-14T12:47:43.7180 SPACECRAFT_CLOCK_START_COUNT = 70.4380 SPACECRAFT_CLOCK_STOP_COUNT = 13043.0180 NATIVE_START_TIME = 70.4380 NATIVE_STOP_TIME = 13043.0180 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.13 REF Data Label PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 10282 FILE_RECORDS = 182 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_REF_123456_0_R_ATMOS.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_REF_123456_0_R_ATMOS.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_REF_123456_0_R_ATMOS.LBL" PRODUCT_CREATION_TIME = 2005-02-01T00:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR START_TIME = 2005-01-14T09:20:21.6980 STOP_TIME = 2005-01-14T12:45:46.7800 SPACECRAFT_CLOCK_START_COUNT = 600.9980 SPACECRAFT_CLOCK_STOP_COUNT = 12926.0800 NATIVE_START_TIME = 600.9980 NATIVE_STOP_TIME = 12926.0800 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.14 THP - Data Label PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 142 FILE_RECORDS = 13260 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_THP_123456_0_R_ATMOS.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_THP_123456_0_R_ATMOS.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_THP_123456_0_R_ATMOS.LBL" PRODUCT_CREATION_TIME = 2005-11-18T14:14:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR START_TIME = 2005-01-14T09:11:22.4740 STOP_TIME = 2005-01-14T12:47:16.8150 SPACECRAFT_CLOCK_START_COUNT = 61.7740 SPACECRAFT_CLOCK_STOP_COUNT = 13016.1150 NATIVE_START_TIME = 61.7740 NATIVE_STOP_TIME = 13016.1150 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" 4.2.15 TIL Data Label PDS_VERSION_ID = PDS3 /* FILE CHARACTERISTICS DATA ELEMENTS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 122 FILE_RECORDS = 16668 /* DATA OBJECT POINTER IDENTIFICATION ELEMENTS */ ^TABLE = "SSP_TIL_123456_0_R_ATMOS.TAB" /* INSTRUMENT AND DETECTOR DESCRIPTIVE DATA ELEMENTS */ FILE_NAME = "SSP_TIL_123456_0_R_ATMOS.LBL" DATA_SET_ID = "HP-SSA-SSP-3/4-DESCENT-V1.0" DATA_SET_NAME = "HUYGENS DESCENT RAW AND CALIBRATED DATA" PRODUCT_ID = "SSP_TIL_123456_0_R_ATMOS.LBL" PRODUCT_CREATION_TIME = 2005-11-23T14:00:00 MISSION_NAME = "CASSINI-HUYGENS" INSTRUMENT_HOST_NAME = "HUYGENS PROBE" INSTRUMENT_HOST_ID = HP MISSION_PHASE_NAME = "DESCENT" PRODUCT_TYPE = EDR START_TIME = 2005-01-14T09:11:25.4700 STOP_TIME = 2005-01-14T12:47:39.7260 SPACECRAFT_CLOCK_START_COUNT = 64.7700 SPACECRAFT_CLOCK_STOP_COUNT = 13039.0260 NATIVE_START_TIME = 64.7700 NATIVE_STOP_TIME = 13039.0260 PRODUCER_ID = "HP_SSP_OU" PRODUCER_FULL_NAME = "AXEL HAGERMANN" PRODUCER_INSTITUTION_NAME = "OPEN UNIVERSITY, PSSRI" TARGET_NAME = "TITAN" The following table gives the definition of the data_quality_flag: (TBC) DATA QUALITY FLAG RAW DATA CALIBRATED DATA 1 Good N/A 2 Poor N/A 4.3 Data Product design All data products will be stored in tables that comprise both voltages and A/D counts in separate columns within the same table. Each row of data contains a time stamp (in seconds after T0), other relevant information like instrument mode and dataset ID (as outlined in [AD-3]) and the measurements. As the data products are very similar in structure we refrain from a complete list for all sensors and modes and only give a few examples. All data will be ordered as contained in the data packets and set out in [AD-3], except for the conversion into voltages which will be added in extra columns. Deviations will be identified in the labels. The following list of product designs is not extensive. A complete list of all object definition is unnecessary as all products are similar. In the following, we detail the Data products of ACCE, ACCI and REF 4.3.1 Data Product Design Example - ACCE Sensor 4.3.1.1 Data Object Definition ACCE_MODE057_TABLE The ACCE data packets consist of one time-tagged time series of 512 values that represent the ACCE impact event. The data is represented as time (s), ACCE measurements (raw ADC counts), ACCE (V). The third column ACCE(V) is directly reduced from the digital numbers (raw ADC counts) by: Voltage = DN / 256.0 * (VOLTAGE_MAX - VOLTAGE-MIN), with VOLTAGE_MAX =+5V and VOLTAGE_MIN=0 V . /* DATA OBJECT DEFINITION */ /* DATA OBJECT DEFINITIION FOR THE ACCE_MODE057_Table */ OBJECT = TABLE NAME = ACCE_MODE057_Table INTERCHANGE_FORMAT = ASCII ROWS = 512 COLUMNS = 6 ROW_BYTES = 72 DESCRIPTION = "ACC-E table" OBJECT = COLUMN COLUMN_NUMBER = 1 NAME = ACCE_SAMPLE_TIME DATA_TYPE = ASCII_REAL START_BYTE = 1 BYTES = 20 DESCRIPTION = "Nominal sample time" UNIT = SECONDS END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 2 NAME = ACCE_MODE DATA_TYPE = ASCII_INTEGER START_BYTE = 21 BYTES = 10 DESCRIPTION = "SSP Mode" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 3 NAME = ACCE_ID DATA_TYPE = ASCII_INTEGER START_BYTE = 31 BYTES = 10 DESCRIPTION = "ACC-E ID" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 4 NAME = ACCE_SEQUENCE DATA_TYPE = ASCII_INTEGER START_BYTE = 41 BYTES = 10 DESCRIPTION = "Sequence no of current sample" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 5 NAME = ACCE_VAL DATA_TYPE = ASCII_INTEGER START_BYTE = 51 BYTES = 10 DESCRIPTION = "8 bit value" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 6 NAME = ACCE_VOLT DATA_TYPE = ASCII_REAL START_BYTE = 61 BYTES = 10 DESCRIPTION = "Acc-E voltage" UNIT = VOLTS END_OBJECT = COLUMN END_OBJECT = TABLE END 4.3.1.2 Data Object Definition ACCE_MODE123_TABLE The ACCE_MODE123_DN_SERIES is used for the data acquired during instrument modes 1, 2 and 3. There are 3 time series in total that will be archived in one file. The length of each time series is 110 values. /* DATA OBJECT DEFINITION */ /* DATA OBJECT DEFINITIION FOR THE ACCE_MODE123_ID2_Table */ OBJECT = TABLE NAME = ACCE_MODE123_ID2 INTERCHANGE_FORMAT = ASCII ROWS = 3 COLUMNS = 212 ROW_BYTES = 2132 DESCRIPTION = "ACC-I compressed impact signature" OBJECT = COLUMN COLUMN_NUMBER = 1 NAME = ACCE_SAMPLE_TIME DATA_TYPE = ASCII_REAL START_BYTE = 1 BYTES = 20 UNIT = SECONDS DESCRIPTION = "Nominal sample time" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 2 NAME = ACCE_MODE DATA_TYPE = ASCII_INTEGER START_BYTE = 21 BYTES = 10 DESCRIPTION = "SSP Mode" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 3 NAME = ACCE_ID DATA_TYPE = ASCII_INTEGER START_BYTE = 31 BYTES = 10 DESCRIPTION = "ACCE datastream packet ID" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 4 NAME = ACCE_MAX_SIG DATA_TYPE = ASCII_INTEGER START_BYTE = 41 BYTES = 10 DESCRIPTION = "8 bit maximum value" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 5 NAME = ACCE_MAX_POS DATA_TYPE = ASCII_INTEGER START_BYTE = 51 BYTES = 10 DESCRIPTION = "offset of peak from start of signature" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 6 NAME = ACCE_PRE_MAX_POS DATA_TYPE = ASCII_INTEGER START_BYTE = 61 BYTES = 10 DESCRIPTION = "offset of leading 1/2 max point from start" END_OBJECT = COLUMN ...ETC... 4.3.1.3 Data Object Definition ACCE Calibrated Data N/A 4.3.2 Data Object Definition Example - ACCI sensor The ACCI data packets consist of one time-tagged time series of 512 values that represent the ACCI impact event. The data is represented as time (s) and ACCI measurements as raw ADC counts and voltages. 4.3.2.1 Data object definition ACCI_MODE057_TABLE /* DATA OBJECT DEFINITION */ /* DATA OBJECT DEFINITIION FOR THE ACCI_MODE057_Table */ OBJECT = TABLE NAME = ACCI_MODE057_Table INTERCHANGE_FORMAT = ASCII ROWS = 512 COLUMNS = 6 ROW_BYTES = 72 DESCRIPTION = "ACC-I table" OBJECT = COLUMN COLUMN_NUMBER = 1 NAME = ACCI_SAMPLE_TIME DATA_TYPE = ASCII_REAL START_BYTE = 1 BYTES = 20 DESCRIPTION = "Nominal sample time" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 2 NAME = ACCI_MODE DATA_TYPE = ASCII_INTEGER START_BYTE = 21 BYTES = 10 DESCRIPTION = "SSP Mode" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 3 NAME = ACCI_ID DATA_TYPE = ASCII_INTEGER START_BYTE = 31 BYTES = 10 DESCRIPTION = "ACC-I ID" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 4 NAME = ACCI_SEQUENCE DATA_TYPE = ASCII_INTEGER START_BYTE = 41 BYTES = 10 DESCRIPTION = "Sequence no of current sample" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 5 NAME = ACCI_VAL DATA_TYPE = ASCII_INTEGER START_BYTE = 51 BYTES = 10 DESCRIPTION = "12 bit value" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 6 NAME = ACCI_VOLT DATA_TYPE = ASCII_REAL START_BYTE = 61 BYTES = 10 DESCRIPTION = "Acci voltage" END_OBJECT = COLUMN END_OBJECT = TABLE END 4.3.2.2 Data Object Definition of ACCI_MODE1236_TABLE The ACCI sensor is sampled continuously at 500Hz through the mission. One set of values in these data packets consist of Mean, Variance, and Maximum values taken over 200 ACCI samples . The data is represented by 7 columns as: TIME (s), ACCI_MEAN (raw ADC counts), ACCI_MEAN (V), ACCI_VAR (raw ADC counts), ACCI_VAR (V), ACCI_MAX (raw ADC counts), ACCI_MAX (V). The voltages ACCI (V) values are reduced from the digital numbers (raw ADC counts) by: Voltage = DN / 4096 * (VOLTAGE_MAX - VOLTAGE-MIN), with VOLTAGE_MAX = +5V and VOLTAGE_MIN= -5 V. 4.3.2.3 Data Object Definition of ACCI Calibrated Data N/A 4.3.3 Data Product Design - APIS Sensor 4.3.3.1 Data Object definition of APIS-MODE23_TABLE The APIS sensor operates from mode2 to the end of mission. The acoustic return signal is formed by 1000 samples measured at 1 millisecond interval. In modes 2 and 3, the data is reduced by selecting a window from the1000 sample acoustic return signal 40th sample to 560th sample and sending an average of 20 samples as 1 value (called bin). Therefore one return signal is represented by 26 such bins. The data is represented by 4 columns as: time (s), bin number, APIS (raw ADC counts), APIS (V). The third column ACCI(V) is directly reduced from the digital numbers (raw ADC counts) by: 4.3.3.2 Data Product Design of APIS-MODE4_TABLE The APIS sensor operates from mode2 to the end of mission. The acoustic return signal is formed by 1000 samples measured at 1 millisecond interval. In mode 4, the data is reduced by transmitting the 60 samples around the peak as uncompressed, and further 140 samples are averaged by 4 with remaining samples averaged by 20. Therefore one return signal is represented by 136 such bins. The data is represented by 5 columns as: time (s), bin number, APIS (raw ADC counts), APIS (V), APIS_PEAK_POS. 4.3.3.3 Data Object definition of APIS-MODE6_TABLE The APIS sensor operates from mode2 to the end of mission. The acoustic return signal is formed by 1000 samples measured at 1 millisecond interval, in surface mode (6), the sensor output is taken from 10 pulses separated by 1 second listening interval. In mode 6, the data is reduced by transmitting 10x50 bins (where each bin contains average value of 20 samples) = 500 bins and also the highest return signal is transmitted as mode4 (i.e. compression centred on the peak). The data is represented by 5 columns as: time (s), bin number, APIS (raw ADC counts), APIS (V), APIS_PEAK_POS. 4.3.3.4 Data Object definition of APIS Calibrated Data N/A 4.3.4 Data Product design, DEN, HK, PER, THP, TIL Data products of DEN, PER, REF and THP do not differ greatly from those presented the previous sections. Data objects will be separated into modes as implemented in the flight software of the individual sensors (cf. [AD-4]). All data will be of the type OBJECT=TABLE, INTERCHANGE_FORMAT=ASCII. 4.3.5 Data Product Design - REF Sensor Ref sensor information contains the complete photodiode array read-out in A/D counts and voltages at every timestep. This results in a 1027 column table. 4.3.5.1 Data Object definition of APIS-MODE23_TABLE /* DATA OBJECT DEFINITION */ /* DATA OBJECT DEFINITIION FOR THE REF_MODE123456_Table */ OBJECT = TABLE NAME = REF_MODE123456_Table INTERCHANGE_FORMAT = ASCII ROWS = 182 COLUMNS = 1027 ROW_BYTES = 10282 DESCRIPTION = "REF table" OBJECT = COLUMN COLUMN_NUMBER = 1 NAME = REF_SAMPLE_TIME DATA_TYPE = ASCII_REAL START_BYTE = 1 BYTES = 20 DESCRIPTION = "Nominal sample time " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 2 NAME = SSP_MODE DATA_TYPE = ASCII_INTEGER START_BYTE = 21 BYTES = 10 DESCRIPTION = "SSP Mode" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 3 NAME = REF_ILLUMINATION DATA_TYPE = ASCII_INTEGER START_BYTE = 31 BYTES = 10 DESCRIPTION = "REF illumination mode" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 4 NAME = REF_SAMPLE DATA_TYPE = ASCII_INTEGER START_BYTE = 41 BYTES = 10 DESCRIPTION = "REF value" END_OBJECT = COLUMN […] 5 Appendix: Available Software to read PDS files N/A 6 Appendix: Auxiliary Data Usage TBD 7 Appendix: Example of Directory Listing of Data Set Please refer to section 3.4.