Ref.:HASI-ICD-UPD-001 Issue: 2 Rev.:2 Date: June 2006 Huygens-HASI To Planetary Science Archive [or NASA PDS] Interface Control Document __________________________________________________ Prepared by: Instrument Archive Responsible Francesca Ferri /CISAS-UPD Pier Francesco Lion Stoppato/CISAS-UPD ______________________________ Approved by: Principal Investigator Marcello Fulchignoni _______________________________________ Approved by: ASI Cassini/Huygens Manager Enrico Flamini Distribution List Recipient/Affiliation Address Role M. Fulchignoni/OBSPM Marcello.fulchignoni@obspm.fr HASI PI J.C. Zarnecki/PSSRI-OU j.c.zarnecki@open.ac.uk HASI CoIs (that provide hardware) A.M. Harri/FMI ari-matti.harri@fmi.fi M. Hamelin/CEPT hamelin@cetp.ipsl.fr F. Simoes/CEPT fernando.simoes@cetp.ipsl.fr K. Schungenschuh/IWF konrad.schwingenschuh@oeaw.ac.at I. Jerney/IWF irmgard.jernej@oeaw.ac.at R. Grard/ ESTEC/RSSD Rejean.grard@esa.int R. Trautner/ ESTEC-RSSD roland.trautner@esa.int H. Svedhem/ ESTEC/RSSD Hakan.svedhem@esa.int P. Falkner/ ESTEC/RSSD Peter.falkner@esa.int J.J. Lopez Moreno/IAA lopez@iaa.es HASI IPMO hasi@dim.unipd.it E. Flamini/ASI enrico.flamini@asi.it ASI representative O. Witasse/ESTEC-RSSD Olivier.witasse@esa.int Huygens PST DA responsible J. Zender/ESTEC-RSSD john.zender@esa.int ESA PSA responsible J-P. Lebreton jean-pierre.lebreton@esa.int Huygens PS Lyle Huber/NASA lhuber@nmsu.edu Huygens PDS DA responsible Change Log Date Sections Changed Reasons for Change 18 June 2003 First draft issue August 2003 Revised in accordance with the Huygens Data Archiving Plan: HUY-RSSD-PL-001 V. 1.0 (14 July 2003) January 2004 Update of Applicable and Reference Documents New document issues Issue 1 Update with data level classification as CODMAC February 2004 Definition of directories structure and data file format. Issue 1 Revision of proposed data products (content and format) within HASI team May 2004 Data filenames convention: shortened Too long >27.3 characters Issue 1.1 Removed LABEL directory December 2004 Revised after EAICD reviewer's report Issue 1.2 January 2006 Revised after [Huygens] Feedback on the Issue 2 HASI EAICD (mail by Olivier & Lyle on 12/10/2005) Very marginal modifications April 2006 Removed TDB ITEMS section New document revision to go with HASI DA data set Issue 2 Rev. 1 Data file naming convention changed section 3.1.4. PWA products defined and confirmed. Added timeline as during mission (Table 3b) and T0 transition in UTC (still TBC by the Project) section 4.3 Sample Labels eliminated Added in annex 3: Table 8: HASI timelines and events during Huygens mission at Titan and Table 9: HASI DPU Event description June 2006 Corrected PWA ACU data file format New document revision after (including burst mode) review of HASI DA data set Issue 2 Rev. 2 section 2.6.1 extended in order to include: - ASCII data calibration files per subsystem and/or reference for higher level product derivation Added ACC L4 product (descent trajectory) Table Of Contents 1. Introduction 20 1.1 Purpose and Scope 20 1.2 Contents 20 1.3 Applicable Documents 20 1.4 Reference Documents 20 1.5 Relationships to Other Interfaces 20 1.6 Intended Readership 20 1.7 Acronyms and Abbreviations 20 1.8 Contact Names and Addresses 23 1.8.1 HASI Contact persons 23 2. Overview of Process and Product Generation 24 2.1 Experiment Overview 24 2.2 Sensor Overview 27 2.2.1 ACC 27 2.2.2 TEM 27 2.2.3 PPI 27 2.2.4 PWA 28 2.3 Operational modes and measurements 28 2.3.1 ACC modes 30 2.3.2 TEM modes 30 2.3.3 PPI modes 30 2.3.4 PWA modes 31 2.3.5 HASI modes of operation 31 2.4 Pre-Flight Data Products 32 2.5 Sub-System Test 32 2.6 Instrument Calibrations 32 2.6.1 Other Files written during Calibration 32 2.7 In-Flight Data Products 32 2.8 Software 33 2.9 Documentation 33 2.10 Derived and other Data Products 33 3. Archive Format and Content 34 3.1 Format and Conventions 34 3.1.1 Deliveries and Archive Volume Format 34 3.1.2 Data Set ID Formation 34 3.1.3 Data Directory Naming Convention 34 3.1.4 Filenaming Convention 34 3.2 Standards Used in Data Product Generation 35 3.2.1 PDS Standards 35 3.2.2 Time Standards 35 3.2.3 Reference Systems 35 3.2.4 Other Applicable Standards 36 3.3 Data Validation 36 3.4 Content 36 3.4.1 Volume Set 36 3.4.2 Data Set 36 3.4.3 Directories 37 3.4.3.1 Root Directory 37 3.4.3.2 Calibration Directory 37 3.4.3.3 Catalog Directory 37 3.4.3.4 Index Directory 38 3.4.3.4.1 Dataset Index File, index.lbl and index.tab 38 3.4.3.4.2 Geometric Index File, geoindex.lbl and geoindex.tab 38 3.4.3.5 Browse Directory and Browse Files 38 3.4.3.6 Geometry Directory 38 3.4.3.7 Software Directory 38 3.4.3.8 Gazetter Directory 38 3.4.3.9 Label Directory 38 3.4.3.10 Document Directory 38 3.4.3.11 Extras Directory 38 3.4.3.12 Data Directory 38 4. Detailed Interface Specifications 39 4.1 Structure and Organization Overview 39 4.1.1 ACC subdirectory 39 4.1.2 TEM subdirectory 41 4.1.3 PPI subdirectory 41 4.1.4 PWA subdirectory 42 4.1.5 HK subdirectory 45 4.1.6 PROFILES (higher level products) 45 4.2 Data Product Design 46 Appendix 1: Data set organization (flow chart) 54 Appendix 2: Available Software to read PDS files 55 Appendix 3: Auxiliary Data Usage 55 Appendix 4: Example of Directory Listing of Data Set 57 1 Introduction 1.1 Purpose and Scope The purpose of this EAICD (Experimenter to (Science) Archive Interface Control Document) is two fold. First it provides users of the HASI instrument with a detailed description of the product and a description of how it was generated, including data sources and destinations. Secondly, it is the official interface between HASI team and ESA PSA (and NASA PDS). 1.2 Contents This document describes the data flow of the HASI instrument on Huygens from the S/C until insertion into the PSA [and/or PDS]. It includes information on how data were processed, formatted, labeled 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.. 1.3 Applicable Documents [AD1]PDS Standards Reference - Revised, October 30, 2002, Version 3.5, http://pds.jpl.nasa.gov/stdref [AD2]Huygens Data Archive Generation, Validation and Transfer Plan HUY-RSSD-PL-001, Issue 1.0, 14 July 2003 1.4 Reference Documents [RD1]HASI Experiment User Manual (Flight and Flight Spare models), HASI-MA-OG-002, Issue 3, 1 December 1998 (II/196.B.6) HASI_USER_MANUAL [RD2]HAS DPU Software User Requirements Document HASI-SP-OG-004, Issue 7, 7 Sep 1995 (II/179.B.1) HASI_SW_URD [RD3]Fulchignoni, Ferri et al The characterisation of Titan's atmospheric physical properties by the Huygens Atmospheric Structure Instrument (HASI) Space Science Reviews, 104, 395-431, 2002 (scientific paper) FULCHIGNONIETAL2002 [RD4]TEM data processing and calibration report HASI-RP-UPD-104 [RD5]PPI data processing and calibration report HASI-RP-UPD-105 [RD6]ACC data processing and calibration report HASI-RP-UPD-106 [RD7]PWA data processing and report HASI-PWA-FM-DOC-041.DOC 1.5 Relationships to Other Interfaces Documents that will be affected by this change will be noted on an as needed basis. 1.6 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 HASI data. 1.7 Acronyms and Abbreviations ACC Accelerometer sensor subsystem ACU Acoustic sensor AD Applicable Document ASI Agenzia Spaziale Italiana C1, C2 TEM 1 (TEM 2) Coarse sensor TM packets (TM formats #98 and #102) CDMS,U Control and Data Management System, Unit CEPT CNRS Observatoire de Saint Maur, France CISAS Centro Interdipartimentale Studi e Attivita Spaziali (CISAS) 'G. Colombo', UPD DBS Deployable Boom Subsystem DDB Descent Data Broadcast DPU Data Processing Unit Subsystem EAICD Experimenter to Archive Interface Control Document ELF Extremely Low Frequency EM Engineering Model ESA European Space Agency ESTEC European Science and Technologies Center F1, F2 TEM 1 (TEM 2) Fine sensor TM packets (TM formats #96 and #100) FM Flight Model FMI Finnish Meteorological Institute FS Flight Spare model HASI HUYGENS Atmospheric Structure Instrument HASI-I HASI PWA Interface boxes H/K Housekeeping H/W Hardware IAA Instituto de Astrofisica Andalusia, Granada, Spain I/F,i/f Interface IPMO Instrument Project Manager Office IWF Institut fur Weltraumforschung, Graz, Austria LESIA Laboratoire d'Environnement Spatial, Obs. Paris-Meudon, France LPCE Lab. de Phisique et Chimique de l'Environment, Orleans, France MCA Magnetic Coil Actuator device MI Mutual Impedance (experiment) MI-Rx MI receiver sensor MI-Tx MI transmitter sensor N/A Not Applicable OG Officine Galileo PDS Planetary Data System PI Principal Investigator PPI Pressure Profile Instrument PSA Planetary Science Archive PSSRI Planetary Space Science Research Institute, The Open University, UK PWA Permittivity, Wave and Altimetry package RAE Radar Altimeter (Proximity sensors) Extension elec. board (DPU s/s) RAU Radar Altimeter Unit RD Reference Document RP,REL RELaxation Probe sensor S/S, s/s Subsystem STUB STUB subsystem S/W Software T0 Mission Time for end of Probe Entry phase (descent device deployment begins) Tacc Mission time when HASI starts to acquire ACC sensors (Td1, Td1w) Mission time window for the first Boom deploy attempt (Td2, Teoff) Mission time window for the second Boom deploy attempt Tdata Mission time when HASI starts to acquire TEM and PRE sensors TdataH Mission time when Probe relay link with Cassini should be set Thigh Mission time when HASI change from MEDIUM to HIGH Normal Session Thasi Mission time when HASI is switched-ON during Titan Descent (before T0 transition) Tmid Mission time when HASI change from LOW to MEDIUM Normal Session Tradar Mission time when HASI starts to acquire Proximity sensors Tproximity Mission Time to start the Impact state when HASI in Back-up sub-mode TBD To Be Defined TEM TEMperature sensors (STUB s/s) Temp 1 Temperature sensor located inside of the Xservo sensor (ACC s/s) Temp 2 Temperature sensor located inside on the ACC mounting block (ACC s/s) TM Telemetry UPD Universita Padova VLF Very Low Frequency Xservo X axis Servo accelerometer sensor (ACC s/s) Xpiezo X axis Piezo accelerometer sensor (ACC s/s) Ypiezo Y axis Piezo accelerometer sensor (ACC s/s) Zpiezo Z axis Piezo accelerometer sensor (ACC s/s) Yvalue Data which is contained in the PPI NORMAL session TM packets 1.8Contact Names and Addresses CISAS - Universita di Padova - ITALY HASI IPMO hasi@dim.unipd.it phone: +390498276798 PSSRI Open University - UK J.C. Zarnecki j.c.zarnecki@open.ac.uk for ACC FMI - Finnish Meteorological Institute Geophysical Research Division - FINLAND A.M. Harri ari-matti.harri@fmi.fi for PPI For PWA: CEPT, S. Maur, France M. Hamelin hamelin@cetp.ipsl.fr F. Simoes simoes@cept.ipsl.fr IWF, Graz, Austria K. Schungenschuh konrad.schwingenschuh@oeaw.ac.at ESTEC/RSSD, The Netherlands, R. Trautner roland.trautner@esa.int H. Svedhem Hakan.svedhem@esa.int for RAU P. Falkner Peter.falkner@esa.int IAA, Granada, Spain J.J. Lopez Moreno lopez@iaa.es 1.8.1 HASI Contact persons Francesca Ferri, CISAS Univ. Padova, Italy, francesca.ferri@unipd.it, phone:+390498276798/6858 Alessio Aboudan, CISAS Univ. Padova, Italy, alessio.aboudan@unipd.it, phone +390498276838 Giacomo Colombatti, CISAS Univ. Padova, Italy , giacomo.colombatti@unipd.it phone: +390498276848 HASI IPMO, CISAS Univ. Padova, Italy, hasi@dim.unipd.it, phone:+390498276798 Principal Investigator: Marcello Fulchignoni, LESIA, Obs. Paris-Meudon- Univ Paris VII, France, Marcello.fulchignoni@obspm.fr, phone : +331450777539 Interface with the PSA/PDS will be managed only by the HASI team at CISAS-UPD. 2 Overview of Process and Product Generation 2.1 Experiment Overview HASI is a multisensor package which has been designed to measure the physical quantities characterizing Titan's atmosphere during the Huygens probe entry, descent and at the surface. The HASI experiment is divided into four subsystems [RD3]: the accelerometers (ACC); the deployable booms system (DBS); the stem (STUB) carrying the temperature sensors, a Kiel probe pressure sampling inlet, an acoustic sensor and the data processing unit (DPU). The HASI subsystems, their acronyms, the institutions responsible for the management (together with the providers) and the elements included are summarised in Table 1. Figure 1. Table 1 : HASI subsystems The scientific measurements are performed by four sensor packages: the accelerometers (ACC), the temperature sensors (TEM), the Pressure Profile Instrument (PPI) and the Permittivity, Wave and Altimetry package (PWA) (see Table 2). In figure 1 the block diagram of the HASI experiment on the Huygens probe in descent configuration. The location of the different subsystems and sensors within the Huygens probe is reported in fig. 2. Figure 2 HASI experiment block diagram Figure 3 Table 2 :HASI sensor packages Figure 4 HASI subsystem accommodation on the Huygens probe experiment platform 2.2 Sensor Overview 2.2.1 ACC The Accelerometer subsystem (ACC) is placed at the centre of mass of the descent module of the Probe. It consists of one highly sensitive single axis accelerometer (Xservo) and three piezoresistive accelometer (X, Y, Z piezo), their conditioning electronics and two temperature sensors (Temp1 and Temp2) used for thermal compensation. The Xservo accelerometer output is amplified providing two channels (HIGH and LOW gain). Each channel has a switchable range (fine and coarse resolution) which is set autonomously (FINE range set at startup and swithched on COARSE prior saturation or anyhow after Tdata (T0+10s)). Xservo channel selection is performed autonomously by checking the measured value against a setable threshold. 7 channels and relevant sampling: - Xservo LOW gain at 100 Hz - Xservo HIGH gain at 100 Hz - Xpiezo at 50 Hz - Ypiezo at 50 Hz - Zpiezo at 50 Hz - Temp 1 (Tservo) at 1.5625 Hz - Temp 2 (Tpiezo) at 1.5625 Hz Values are arithmetically averaged by the HASI onboard S/W to produce lower sampling rates. 2.2.2 TEM HASI temperature sensors are two redundant dual element platinum resistance thermometers (TEM) mounted on the STUB in order to be appropriatelly located and oriented with respect to the gas flow during the measurements. Each TEM has a primary sensor (fine, F) directly exposed to the air flow and a secondary sensor (coarse, C) which is annealed in glass of the supporting frame and is used as spare unit in case of damage on the primary sensor. Temperature measurement is performed by monitoring the resistance of TEM sensors; the resistance of each TEM sensor is measured by a four wire configuration. Temperature measurements can be performed in HIGH and LOW resolution range (60-110K for HIGH and 100-330K for LOW resolution ) by switching HIGH and LOW gain channel. The range selection is performed by HASI S/W calculating the rough resistor value and comparing against a setable threshold. 4 sensors: - TEM1 fine (F1) - TEM1 coarse (C1) - TEM2 fine (F2) - TEM2 coarse (C2) 2.2.3 PPI The Pressure Profile Instrument includes sensors for measuring the atmospheric pressure during descent and surface phase. The atmospheric flow is conveyed through a Kiel probe, mounted on the STUB tip, inside the DPU where the transducers and related electronics are located. The PPI sensors are 6 reference sensors (for housekeeping) and 18 transducers. The transducers are silicon capacitive absolute pressure sensors (Barocap, 8 P), temperature capacitive sensors (Thermocap, 3 T) and Constant (C) and reference (R) sensors (high stability capacitor, respectively 7 C used for housekeeping and 6 R used in the pressure measurements) The sensors are organized in three blocks each having eight frequency output channels. The three blocks corresponds to different pressure sensibility range: low pressure 0-400 hPa block 3, sensor 3.7P , 3.8P and 3.3T medium pressure 0-1200 hPa block 1, sensor 1.1P, 1.6P , 1.8P and 1.3T high pressure 0-1600 hPa block2, sensor 2.1P, 2.7P, 2.8P and 2.3T In total there are: 24 frequency channels: 1.1P 2.1P 3.1C 1.2R 2.2R 3.2R 1.3T 2.3T 3.3T 1.4C 2.4C 3.4C 1.5R 2.5R 3.5R 1.6P 2.6C 3.6C 1.7C 2.7P 3.7P 1.8P 2.8P 3.8P and 2 housekeeping voltages (HKV0 and HKV1 for housekeeping). 2.2.4 PWA The PWA sensors are 6 electrodes and an acoustic transducer. The electrodes are mounted on the deployable booms system (DBS), 3 electrodes on each boom - transmitter TX (ring-shape), receiver RX (ring-shape), and relaxation probe RP (disk-shape)-, and can operate in different modes. The two RP electrodes are independent relaxation probes with different sensitivity. The two transmitters and two receivers are part of the mutual impedance probe (active mode). Furthermore, when the transmitters are off, the receivers located at the tip of the booms operate as an antenna (passive mode). The relaxation probes measure ion conductivities and the mutual impedance probe is sensitive to electron conductivity only. The passive mode operation allows the detection of electromagnetic waves in the ELF-VLF range. The acoustic sensor (ACU) is mounted on the STUB for detecting sound waves to correlate with acoustic noise, turbulence and meteorological events. The radar return signals of the Huygens Proximity Sensor, containing information on surface properties and altitude, are processed also by HASI. The radar signal is converted to 10KHz and filtered by the Radar Altimeter Extension (RAE) board and passed to the PWA A/D converter and signal processor. The radar input signals in HASI/PWA are the blanking signal and the analogue intermediate frequency signal (echo signal). The PWA signal processor performs FFT, digital integration and data packetising and controls the data acquisition. The spectrum and altitude information of the radar return signal are added to the HASI data stream. Data products: PWA-ACU Acoustic (High and Low gain) (Descent 2 and 3; Surface) PWA-RP Relaxation probe (Descent 2 and 3) PWA-MI Mutual Impedance (Descent 2 and 3; Surface) PWA-AC_VLF AC Field VLF range (Descent 2, Descent 3; Surface) (High and Low gain) PWA-AC_ELF AC Field ELF range (Descent 2, Descent 3; Surface) (High and Low gain) PWA-LGH Lightning (Descent 2 and 3; Surface) PWA-RAU Radar (Descent 3) 2.3 Operational modes and measurements HASI mission phases ENTRY from higher than 1270 km (~1900 km) to 170 km; Tacc=Probe-ON +21min 30s to T0 (expected at 28 min) DESCENT from Tdata=T0+10s to surface DESCENT 1st state from Tdata to TdataH=T0+2min 30s DESCENT 2nd state from TdataH to Tradar=T0+32min DESCENT 3rd state from Tradar to last km (~T0+2h12min) IMPACT state from last km to surface (~T0+2h14min) SURFACE state from ACC impact detection to link loss Figure 5 Table 3 :HASI timeline, probe events and related dynamic conditions during the Huygens mission as expected. (as from Huygens engineering profile for recommended Yelle's atmosphere model as in EIDpartC, reviewed by Alcatel in 1997) 2.3.1 ACC modes For the acceleration there are two types of data: 'raw' data and statistics data (obtained from average of 100 Hz sampling, on-board processing). Channels readouts are summed in order to get the following sampling rate: ACC Xservo 3.125 Hz in ENTRY; from Tacc till T0+10 s 4.167 Hz till T0+32 min 1.754 Hz last km (~132 min) Impact detection and in Surface state ACC X, Y, Z piezo 1.6129 Hz in ENTRY and last km and in Surface state Statistics 0.1 Hz always, except in impact detection ACC Servo & piezo Temperature 0.097 Hz always, except in impact detection Impact trace (0.5 s before & 5.5 s after impact) X piezo 200 Hz Y piezo 200 Hz transmitted after Timpact Z piezo 200 Hz p.s. NO ACC data are transmitted during impact phase 2.3.2 TEM modes All 4 TEM sensors are sampled every 5 s. The measurement sequence is the following: F1,C1, F2, C2. Sampling rate: 1 Temperature point every 1.25s (0.8 Hz) but same sensor sampled every 5s (0.2Hz) IMPACT STATE only F1 and F2 are sampled 1 Temperature point every 1.25s (0.8 Hz) but same sensor sampled every 2.5s (0.4Hz) 2.3.3 PPI modes Table 4 : PPI modes DDB time HASI time PPI normal session T0+10s Tdata A Low pressure T0+75m Tpmed B Medium p sampling start T0+105m Tphigh C High p sampling start Two pressure values every 2.3 s are produced. PPI channels polling tables for normal and health check session are reported in PPI calibration report [RD5]. 2.3.4 PWA modes Figure 6 Table 5: PWA modes 2.3.5 HASI modes of operation Figure 7 Table 6: HASI operation modes ACC statistics average on samples @400 Hz ACC PIEZO special buffer at 200 Hz, from Timpact-0.5s to Timpact+5.5s ACC no data transmitted during impact phase (except for impact detection trace) TEM F1, C1, F2, C2 (F: fine, C: coarse); impact phase F1, F2 (only fine) PPI measurement sequence provide 2 pressure point every 2.3s A: low pressure range, B: medium pressure range, C: high pressure 2.4Pre-Flight Data Products We do not currently plan to include pre-flight data products. 2.5Sub-System Test We do not plan to include any subsystem tests. 2.6Instrument Calibrations Calibration and data processing will be detailed in the HASI subsystem calibration reports: TEM calibration report [RD4] PPI calibration report [RD5] ACC calibration report [RD6] PWA report [RD7] Calibration reports will contain all the information (Transfer functions, lookup table, algorithm to convert engineering data to science products) for processing and calibrate the data derived from the different HASI sensor packages. 2.6.1 Other Files written during Calibration ASCII calibration data files are also provided within the CALIB directory per subsystem containing information on data conversions and calibration parameters (e.g. formulae, coefficients). When necessary, also ASCII files containing information on higher level products derivation are provided. In general for the description of the methods of data analysis clear reference to scientific papers or documents are indicated either in calibration reports or in references. 2.7 In-Flight Data Products The following data products are processing level 2 (raw data converted into engineering units) 3 and 4 (and elaborated in scientific units), converted in ASCII. The HASI data products are listed in table 7, the size of each product is stated just for reference and it is a minimum estimation on the base only of level 2 data. Figure 8 Table 7: HASI data products 2.8 Software No software will be provided (data will be provided in ASCII form so as the calibration documents) 2.9 Documentation Documentation will be provided to give instructions to how to use the calibration data (calibration report) and converting data from engineering units to science product. ASCII documents will be provided; in case of images and drawing WORD and/or PDF document will be provided. 2.10 Derived and other Data Products Any derived data products will be completed on the best effort basis, as time and funding permit. 3 Archive Format and Content 3.1 Format and Conventions 3.1.1 Deliveries and Archive Volume Format The individual logical archive volumes delivered will contain: Data from ALL sensors (including housekeeping) Raw data (e.g. data in engineering units), converted and calibrated data (namely engineering data converted into scientific data) as well calibration data The logical archive volumes identified at the moment are: Titan mission 3.1.2 Data Set ID Formation Data set ID complaiant with PDS standard will be indicated as follow (acronyms meaning is reported within <>): HP-SSA-HASI-dpl-MISSION-V1.0 ----- Level 2 is data converted in engineering units; Level 3 converted to scientific units, Level 4 is high scientific product. *see ANNEX I of [AD2] should be complaint with CODMAC PROCESSING LEVELS (see chapter 6 B [AD1] 3.1.3 Data Directory Naming Convention For all the data sets, the subdirectories will be named according to the data products, in the /data directory with the following naming scheme: /data/{subsystem}/filename, with subsystem={ACC, PPI, TEM, PWA, HK} The calibration data will be archived in the /calib directory below the root directory, as: /calib/{subsystem}/filename, with subsystem={ACC, PPI, TEM, PWA, HK} 3.1.4 Filenaming Convention The following filename scheme is used for all the data files. HASI_L{data processing level}_{subsystem}{mission phase}_{datatype}.{extension} data processing level {2, 3, 4} according to CODMAC processing level[AD1, AD2] subsystem {ACC, TEM, PPI, PWA, DPU} mission phase {E = entry , D = descent, S = surface} when applicable sensor data type {SERVO, SERVOSTD, SERVOT, PIEZO, PIEZOSTD, PIEZOT, PIEZOIMP}; {FINE1, COARSE1,...}; {NSA,HCA, HK, NSA11P, NSA13T, ...}; {RP, AC_ELF, AC_VLF, ACU, LGH, MIP, RAU} extension {LBL = label, TAB = table} Max filename length 27.3 3.2 Standards Used in Data Product Generation 3.2.1 PDS Standards PDS Standard Reference version 3.5, http://pds.jpl.nasa.gov/stdref was used for the design of the HASI archive. 3.2.2 Time Standards The time reference (Mission Time) is given by the Huygens timer provided to the instrument in the DDB by the CDMS. HASI receives a DDB information every 2 s and is synchronized every 125 ms by the BCP (BroadCast Pulse) signal. In preT0 (entry phase), time is referenced to Huygens probe power on (S0); after entry time is referenced to T0 (arming time of the Descent Device Deployment System pyros) [ref. to EIDA; table 3]. HASI marks each telemetry packets with a timestamp relevant to the DDB time when the first source data contained in the packet data field is created. Timestamp resolution is a BCP count (125 ms); the resolution on this time value is 1 LSB = 1ms. Time relevant to each data value contained in the telemetry packet is computed starting from the timestamp, according to their position within the packets and from the sampling rate (constant). Conversion from DDB time (Mission Time) to UTC time will be provided by HPOC. The format for time that HASI intends to use is UTC time YYYY-MM-DDThh:mm:ss.xxx (e.g. 2005-01-25T12:09:09.999) and I8 (8-digit integer number) [ms] DDB time h:mm:ss.xxx or I8 (8-digit integer number) [ms] (spacecraft clock time) (DDB time starts at Probe ON and is reset to 0 at T0) signed "-" for preT0 Native time I8 (8-digit integer number) [ms] (Elapsed time from T0) signed: "-" for preT0 N.B. Conversion time from DDB to UTC time provided by HPOC (could be changed). For this data set the following value has been used: To transition at UTC time 9:10:20.828 (corresponds to 33020828 milliseconds starting from 2005-01-14T00:00:00.000 UTC.) T0 transition happened at DDB time 4:28:47.875 (16127875 ms) corresponding to UTC time 9:10:20.828 (information provided by HPOC and contained in the Huygens HK parameter S2013E_H3B) 3.2.3 Reference Systems The reference system for HASI is the Huygens probe system axes. The official trajectory reconstruction is the result of a common effort, produced by the Huygens Descent Trajectory Working Group (DTWG) and archived within the Huygens DTWG data set. Huygens reference system: Titan centric coordinates (as defined by DTWG) ([AD2]). 3.2.4 Other Applicable Standards N/A 3.3 Data Validation HASI data products will be validate internally within the HASI team by interactions with the HASI CoIs, responsible for the different subsystems. The final validation will be performed by the HASI PMO at CISAS - UPD under the PI supervision and endorsement by Italian Space Agency (ASI). 3.4 Content 3.4.1 Volume Set N/A 3.4.2 Data Set Data are organized in directories for each HASI subsystems (ACC, PPI, TEM, PWA, HK) within these directories data files relevant to the different measurements and derived parameters are contained. Data directory and filename conventions are stated in section 3.1. Data set id name: HP-SSA-HASI-2-3-4-TITAN-V1.0 ref. 3.1.2 HP-SSA-HASI-2-3-4-TITAN-V1.0 _____________________________________|_________________________________ | | | | | | Data Calib Catalog Index Label Document | | |-ACC |-ACC | | |-TEM |-TEM | | |-PPI |-PPI | | |-PWA |-PWA | | |-HK |-HK |-PROFILES See ANNEX 1. Figure 9 Table8: HASI data products 3.4.3 Directories 3.4.3.1 Root Directory Root Directory will be / HP-SSA-HASI-2/3/4-TITAN-V1.0/. 3.4.3.2 Calibration Directory Calibration directory will be /CALIB/. Subdirectories will be divided for HASI subsystems: /ACC /TEM /PPI /PWA /HK These directories will contain the calibration reports and data. 3.4.3.3 Catalog Directory The Catalog Directory will contain the following files: MISSION.CAT (to be provided by the project) INSTRUMENTHOST.CAT (to be provided by the project) INSTRUMENT.CAT containing a description of the instrument DATASET.CAT containg a description of the dataset and relevant information REFERENCE.CAT containing a list of scientific papers PERSONNEL.CAT containing list and coordinates of personnel involved TARGET.CAT containg the name of the target SOFT.CAT not applicable, but requested by PDS CATINFO.TXT 3.4.3.4 Index Directory 3.4.3.4.1 Dataset Index File, index.lbl and index.tab 3.4.3.4.2 Geometric Index File, geoindex.lbl and geoindex.tab N/A 3.4.3.5 Browse Directory and Browse Files N/A 3.4.3.6 Geometry Directory N/A 3.4.3.7 Software Directory N/A We do not foresee any software to be archived. 3.4.3.8 Gazetter Directory N/A 3.4.3.9 Label Directory N/A 3.4.3.10 Document Directory Within this directory will be contained documents useful and relevant to data processing and analysis. Documents are provided in PDF format. Documents are divided into directory: EAICD USER_MANUAL: containing HASI technical documents: HASI_USER_MANUAL HASI Experiment User Manual (Flight and Flight Spare models), HASI-MA-OG-002, Issue 3, 1 December 1998 (II/196.B.6) [RD1] HASI_SW_URD HAS DPU Software User Requirements Document HASI-SP-OG-004, Issue 7, 7 Sep 1995 (II/179.B.1) [RD2] PUBLICATIONS: containing HASI general description papers and publication of the preliminary results and reference for HASI subsystems: 3.4.3.11 Extras Directory N/A HASI home page at CISAS-UPD http://cisas.unipd.it/hasi/ IWF HASI-PWA web site http://saturn.iwf.oeaw.ac.at/iwfmag/cassini/index.htm 3.4.3.12 Data Directory This directory contains all the data products of HASI (at different processing level) organized in subdirectories containing different data files. Subdirectories are divided for HASI subsystems plus a directory for higher level products (PROFILES): /ACC /TEM /PPI /PWA /HK /PROFILES Within these directories data files relevant to different sensors, mission phase, measured parameters etc. will be contained. The filename (as from section 3.1.4) will help for understanding the content of the file. 4. Detailed Interface Specifications 4.1 Structure and Organization Overview /HP-SSA-HASI-2/3/4-TITAN-V1.0/data directory will be organized in subdirectories. Subdirectories will be divided for HASI subsystems plus a directory for higher level products (PROFILES): /ACC /TEM /PPI /PWA /HK /PROFILES Filename convention as from section 3.1.4: HASI_L{data processing level}_{subsystem}{missionphase}_{datatype}.{extension} data processing level {2, 3, 4} according to CODMAC processing level[AD1, AD2] subsystem {ACC, TEM, PPI, PWA, DPU} mission phase {E = entry , D = descent, S = surface} when applicable sensor data type {SERVO, SERVOSTD, SERVOT, PIEZO, PIEZOSTD, PIEZOT, PIEZOIMP}; {FINE1, COARSE1,....}; {NSA,HCA, HK, NSA11P, NSA13T, ....}; {RP, AC_ELF, AC_VLF, ACU, LGH, MIP, RAU} extension {LBL = label, TAB = table} 4.1.1 ACC subdirectory The following files are inserted in this subdirectory (naming convention as from section 3.1.4). In what follow it is reported the file name and a schematic structure of the content of the table: ref. to [RD6] ENTRY PHASE ENGINEERING DATA (level 2): HASI_L2_ACCE_SERVO.TAB/LBL Time [ms] voltages [V] gain [high/low] range [fine/coarse] HASI_L2_ACCE_SERVOSTD.TAB/LBL Time [ms] voltages [V] gain [high/low] range [fine/coarse] HASI_L2_ACCE_SERVOT.TAB/LBL Time [ms] temperature [V] HASI_L2_ACCE_Piezo.TAB/LBL Time [ms] Xpiezo [V] Ypiezo [V] Zpiezo [V] HASI_L2_ACCE_PiezoSTD.TAB/LBL Time [ms] Xpiezo [V] Ypiezo [V] Zpiezo [V] HASI_L2_ACCE_PIEZOT.TAB/LBL Time [ms] temperature [V] ENTRY PHASE SCIENTIFIC DATA (level3): HASI_L3_ACCE_SERVO.TAB/LBL Time [ms] acceleration [m/s2] HASI_L3_ACCE_SERVOSTD.TAB/LBL Time [ms] acceleration [m/s2] HASI_L3_ACCE_SERVOT.TAB/LBL Time [ms] temperature [K] HASI_L3_ACCE_Piezo.TAB/LBL Time [ms] Xpiezo [m/s2] Ypiezo [m/s2] Zpiezo [m/s2] HASI_L3_ACCE_PiezoSTD.TAB/LBL Time [ms] Xpiezo [m/s2] Ypiezo [m/s2] Zpiezo [m/s2] HASI_L3_ACCE_PIEZOT.TAB/LBL Time [ms] temperature [K] DESCENT PHASE: (same structure that in ENTRY, for Piezo only statistic data will be measured) HASI_LX_ACCD_SERVO.TAB/LBL HASI_LX_ACCD_SERVOSTD.TAB/LBL HASI_LX_ACCD_SERVOT.TAB/LBL HASI_LX_ACCD_PiezoSTD.TAB/LBL HASI_LX_ACCD_PiezoT.TAB/LBL LEVELX with X=2 & 3 SURFACE PHASE: (during impact Piezo sensors acquired at 100 Hz frequency) HASI_LX_ACCS_PiezoIMP.TAB/LBL (same structure that DESCENT, for Piezo only statistic data will be measured) HASI_LX_ACCS_SERVO.TAB HASI_LX_ACCS_SERVOSTD.TAB HASI_LX_ACCS_SERVOTEM.TAB HASI_LX_ACCS_PiezoSTD.TAB HASI_LX_ACCS_PiezoT.TAB LEVELX with X=2 & 3 Higher level products (LEVEL4) Acceleration profile of the Huygens probe relevant to entry phase Velocity of the Huygens probe expressed in Titan centric coordinates (ref section 3.2.3) or vertical velocity as derived from trajectory reconstruction Altitude as derived from trajectory reconstruction Density profile relevant to entry phase as derived from acceleration profile [RD3, RD6] using Huygens probe characteristics and aerodynamic database. HASI_L4_ACCE_acc_VEL.TAB Time [ms] Altitude [m] acceleration [m/s2] VX [m/s] VY [m/s] VZ [m/s] HASI_L4_ACCE_density.TAB Time [ms] Altitude [m] density [kg/m3] HASI_L4_ACCD_ALT_VEL.TAB Time [ms] Alt [m] 1sigma alt [m] Vertical velocity[m/s] 1sigma velocity[m/s] 4.1.2 TEM subdirectory The following files are expected to be inserted in this subdirectory (naming convention as from section 3.1.4). In what follow it is reported the file name and a schematic structure of the content of the table: ref to [RD4] HASI_L2_TEMX_Y.TAB/LBL Time [ms] VF[V] 0VF[V] VR [V] 0VR [V] gain[high/low] 0VRMEAN [V] 0VFMEAN [V] HASI_L3_TEMX_Y.TAB/LBL Time [ms] Resistance [ohm] temperature [K] with X = D, S with Y = FINE1, COARSE1, FINE2, COARSE2 Higher level products (LEVEL4) refer to [RD4] Corresponding to temperature values corrected for instrumental response effects and dynamical effects. HASI_L4_TEM_Temperature.TAB Time [ms] Altitude [h] temperature [K] +/-uncertainty [K] Ref sensor Including also temperature data recorded at surface after landing for almost half an hour. 4.1.3 PPI subdirectory The following files are inserted in this subdirectory (naming convention as from section 3.1.4). In what follow it is reported the file name and a schematic structure of the content of the table: ref to [RD5] ENGINEERING DATA (level2): HASI_L2_PPI_X.TAB/LBL Time [ms] Channel type Counter with X = NSA, NSB, NSC, HCA, HCB NS = normal session HC = health check HASI_L2_PPID_HK.TAB/LBL Time [ms] HK voltage 1 [Volt] HK voltage2 [Volt] SCIENTIFIC DATA (level 3): Scientific data for normal session will divided with respect to measurement channel. HASI_L3_PPI_XYP.TAB/LBL Time [ms] Pressure [Pa] with X = NSA, NSB, NSC with Y = 11, 16, 18, 21, 27, 28, 37, 38(corresponding to PPI channel ref2.2.3) HASI_L3_PPID_XYT.TAB/LBL Time [ms] Temperature [K] with X = NSA, NSB, NSC with Y = 13, 23, 33 (corresponding to temperature channel) Higher level products (LEVEL4) corresponding to total and ambient pressure, descent velocity, and altitude profiles has reconstructed by PPI team starting from total pressure measurements (using real gas and hydrostatic equilibrium) [RD5] HASI_L4_PPI_pressure_Vel.TAB Time [ms] Ref sensor tot pres [Pa] ambient pressure [Pa] Alt [m] vel [m/s2] Including also pressure data recorded at surface after landing for almost half an hour. 4.1.4 PWA subdirectory The following files are inserted in this subdirectory (naming convention as from section 3.1.4). In what follow it is reported the file name and a schematic structure of the content of the table: Figure 10 Legend: x - is 2 or 3. Level 2 tables will be delivered in LSB (Least Significant Bit), as converted from Telemetry Data File. Level 3 tables will be delivered in SI units. NOTE: As calibration data is model dependent, PWA team will not be able to provide level 4 data at the present stage, not only electron and ion density but also conductivity profiles. RelaxationProbe HASI_L2_PWAD23_RP.TAB/LBL Time[ms] InitialVoltage RelaxationValue1 ... RelaxationValue97 0=>0V 1=>+5V 2=>-5V VLF Field HASI_L2_PWAD2_AC_VLF.TAB/LBL Time[ms] GainMode SpectralLineL1 ... SpectralLineL32 0=>Low 180Hz 11340Hz 1=>High HASI_L2_PWAD3_AC_VLF.TAB/LBL Time[ms] GainMode SpectralLineL1 ... SpectralLineL14 0=>Low 720Hz 10080Hz 1=>High HASI_L2_PWAS_AC_VLF.TAB/LBL Time[ms] GainMode SpectralLineL1 ... SpectralLineL14 0=>Low 720Hz 10080Hz 1=>High Mutual Impedance Probe HASI_L2_PWAD23_MIP.TAB/LBL Figure 11 HASI_L2_PWAS_MIP.TAB/LBL Figure 12 Lightning HASI_L2_PWAD23_LGH.TAB/LBL Time[ms] Freq-L[Hz] Bw-L[Hz] L1 ... L40 Freq-M[Hz] Bw-M[Hz] L1 ... L40 Freq-H[Hz] Bw-H[Hz] L1 ... L40 HASI_L2_PWAS_LGH.TAB/LBL Time[ms] Freq-L[Hz] Bw-L[Hz] L1 ... L40 Freq-M[Hz] Bw-M[Hz] L1 ... L40 Freq-H[Hz] Bw-H[Hz] L1 ... L40 Freq-x=>FrequencyLow,Medium,High Bw-x=>BandwidthLow,Medium,High L1-L40=>SpectralLineL1-L40 ELF Field HASI_L2_PWAD2_AC_ELF.TAB/LBL Time[ms] SpectralLineL1 ... SpectralLineL16 6Hz 96Hz HASI_L2_PWAD3_AC_ELF.TAB/LBL Time[ms] SpectralLineL1 ... SpectralLineL8 10.5Hz 94.5Hz HASI_L2_PWAS_AC_ELF.TAB/LBL Time[ms] SpectralLineL1 ... SpectralLineL8 10.5Hz 94.5Hz Acoustic HASI_L2_PWAD3_ACU.TAB/LBL Time [ms] L1 ... L14 burst f Low burst wd Low L1 ... L10 Burst f High Burst wd High L1 ... L10 HASI_L2_PWAS_ACU.TAB/LBL Time [ms] L1 ... L14 burst f Low burst wd Low L1 ... L10 Burst f High Burst wd High L1 ... L10 Burst f => Burst frequency Low and High Burst bd => Burst Bandwidth Low, High L1-L10 and L1-L14 => Spectral Line L1-L10 and L1-L14 Radar HASI_L2_PWAD3_F52_RAU.TAB /LBL Time [ms] L1 [Hz] ... L52 [Hz] L1 [Hz] ... L52 [Hz] 1 + 2 x 52 columns 1x HASI_L2_PWAD3_F26_RAU.TAB /LBL Time [ms] L1 [Hz] ... L26 [Hz] L1 [Hz] ... L26 [Hz] 1 + 4 x 26 columns 2x HASI_L2_PWAD3_F13_RAU.TAB /LBL Time [ms] L1 [Hz] ... L13 [Hz] L1 [Hz] ... L13 [Hz] 1 + 8 x 13 columns 4x HASI_L2_PWAD3_F0_RAU.TAB /LBL Time [ms] T1 [ms] ... T104 [ms] 1 + 104 columns LEVEL 3 To be defined (TBD) 4.1.5 HK subdirectory The following files will be inserted in this subdirectory (naming convention as from section 3.1.4). In what follow it is reported the file name and a schematic structure of the content of the table: HASI_L2_DPU_TEMP.TAB/LBL Time [ms] Voltage [V] HASI_L3_DPU_TEMP.TAB/LBL Time [ms] Temperature [K] HASI_L2_DPU_EVENT.TAB/LBL Time [ms] Event 4.1.6PROFILES (higher level products) The following files are expected to be inserted in this subdirectory (naming convention as from section 3.1.4). In what follow it is reported the file name and a schematic structure of the content of the table: These data files are relevant to higher level products deduced from HASI direct and/or derived measurements. The atmospheric vertical profile in terms of pressure, temperature, and density as derived from accelerometric data during entry and direct pressure and temperature during the descent. HASI_L4_Atmo_profile_ENTRY.TAB Time [ms] Altitude [m] pressure [Pa] temperature [K] density [kg/m3] HASI_L4_Atmo_profile_descen.TAB Time [ms] Altitude [m] pressure [Pa] temperature [K] density [kg/m3] Trajectory in terms of vertical velocity and altitude profiles HASI_l4_velocity_profile.TAB Time [ms] Altitude [m] velocity [m/s] Ref sensor HASI_l4_altitude_profile.TAB Time [ms] Altitude [m] Ref sensor N.B. The TIME reported in the first column is the mission time (DDB time) expressed in milliseconds [ms] starting from Probe switch on, reset to 0 at T0. 4.2 Data Product Design Data files as included in the different subdirectories of the DATA directory are listed as for the data products defined in table 7. For each file it is reported numbering, filename, type, no of columns, a brief description of the content and the relevant mission phase. ACC engineering and scientific data Figure 13 ACC higher level products Figure 14 TEM engineering and scientific data Figure 15 TEM higher level products Figur 16 PPI engineering and scientific data Figure 17 PPI higher level products Figure 18 PWA engineering and scientific data Figure 19 HASI_HK Figure 20 PROFILES (higher level products) Figure 21 Appendix 1: Data set organization (flow chart) Figure 22 Appendix 2: Available Software to read PDS files N/A Appendix 3: Auxiliary Data Usage Figure 23 Table 8 HASI timelines and events during Huygens mission at Titan Figure 24 Table 9 HASI DPU Event description Appendix 4: Example of Directory Listing of Data Set HP-SSA-HASI-2/3/4-MISSION-V1.0 \DATA \ACC HASI_L2_ACCE_SERVO.TAB/LBL HASI_L2_ACCE_SERVOSTD.TAB/LBL HASI_L2_ACCE_SERVOTEM.TAB/LBL HASI_L2_ACCE_PIEZO.TAB/LBL HASI_L2_ACCE_PIEZOSTD.TAB/LBL HASI_L2_ACCE_PIEZOTEM.TAB/LBL HASI_L3_ACCE_SERVO.TAB/LBL HASI_L3_ACCE_SERVOSTD.TAB/LBL HASI_L3_ACCE_SERVOTEM.TAB/LBL HASI_L3_ACCE_PIEZO.TAB/LBL HASI_L3_ACCE_PIEZOSTD.TAB/LBL HASI_L3_ACCE_PIEZOTEM.TAB/LBL HASI_L2_ACCD_SERVO.TAB/LBL HASI_L2_ACCD_SERVOSTD.TAB/LBL HASI_L2_ACCD_SERVOTEM.TAB/LBL HASI_L2_ACCD_PIEZOSTD.TAB/LBL HASI_L2_ACCD_PIEZOTEM.TAB/LBL HASI_L3_ACCD_SERVO.TAB/LBL HASI_L3_ACCD_SERVOSTD.TAB/LBL HASI_L3_ACCD_SERVOTEM.TAB/LBL HASI_L3_ACCD_PIEZOSTD.TAB/LBL HASI_L3_ACCD_PIEZOTEM.TAB/LBL HASI_L2_ACCS_PIEZOIMP.TAB/LBL HASI_L3_ACCS_PIEZOIMP.TAB/LBL HASI_L2_ACCS_SERVO.TAB/LBL HASI_L2_ACCS_SERVOSTD.TAB/LBL HASI_L2_ACCS_SERVOTEM.TAB/LBL HASI_L2_ACCS_PIEZOSTD.TAB/LBL HASI_L2_ACCS_PIEZOTEM.TAB/LBL HASI_L3_ACCS_SERVO.TAB/LBL HASI_L3_ACCS_SERVOSTD.TAB/LBL HASI_L3_ACCS_SERVOTEM.TAB/LBL HASI_L3_ACCS_PIEZOSTD.TAB/LBL HASI_L3_ACCS_PIEZOTEM.TAB/LBL HASI_L4_ACCE_acc_VEL.TAB HASI_L4_ACCE_density.TAB