PDS_VERSION_ID = PDS3 LABEL_REVISION_NOTE = "V1.0" RECORD_TYPE = STREAM OBJECT = TEXT NOTE = "Rosetta GIADA data during Commissioning 2 phase" PUBLICATION_DATE = 2011-03-04 END_OBJECT = TEXT END Rosetta GIADA data during Commissioning 2 phase 1. Introduction This volume contains Experiment Data acquired by GIADA during 'Commissioning 2' phase. More in detail it refers to the data provided during the following in-flight scenarios: 'Interference 1' held on 20/21/22-09-2004; 'Pointing 1' held on 23-09-2004; 'Pointing 2' held on 30-09-2004; 'Interference 2' held on 12/13/14-10-2004. It also contains documentation which describes the GIADA experiment. Aims of the Interference tests were to check interference induced by and/or suffered from GIADA with respect to other payload switch on/off and operations in different modes, according to the Interference scenario plan prepared by ESA. Interference Test n. 1 was divided in parts 1A (from 20 to 21 September 2004) and 1B (from 21 to 22 September 2004). The Interference scenario 1A was divided, for GIADA, in two sections: the first (INT1A_01_MAIN), in which GIADA was switched on Main I/F for approximately one and half hours, and the second (INT1A_02_MAIN), starting from the evening of 20 of September, in which GIADA was switched on Main I/F for about five hours. In the Interference scenario 1B, GIADA was switched on Main I/F for approximately nine hours starting from the afternoon of 21 of September. Data related to this scenario were further separated into parts INT1B_PART1 and INT1B_PART2 due to a more easy data processing and handling. Interference Test n. 2 was divided in parts 2A, 2B and 2C. GIADA Interference scenario 2A was executed on 12-13 October 2004 by switching on Main and Redundant I/Fs in sequence for about sixteen hours (INT2A_MAIN and INT2A_RED). In the Interference scenario 2B (INT2B_MAIN), GIADA was switched on Main I/F for about one and half hours starting from the afternoon of 13 of October. At last GIADA Interference scenario 2C was executed on 14 October 2004 by switching on Main I/F for approximately three and half hours (INT2C_MAIN). During the Interference tests GIADA was mainly operated in its nominal mode and calibration was repeated at different rates to acquire calibration and housekeeping data. MBS heating was also performed. The objective of the Pointing tests was to evaluate the behaviour of GIADA (and the other on board payloads) induced by the different angles of the sunlight. To this aim GIADA was put in Normal Mode in nominal operation conditions and calibration was repeated periodically to check calibration and housekeeping data. Pointing tests were performed on 23 and 30 September 2004, according to the Interference-Pointing scenario plan provided by ESA. In the Pointing Test n. 1 (perforfmed on 23 September 2004), the Rosetta S/C was manoeuvred to get sun light from GIADA –X axis and to change the angle of the sunlight with respect to the S/C +Z axis (which is along GIADA bore-sight) from 80 to 45 deg with steps of 5 deg. At the end of the Pointing Test n. 1, an unexpected Cover final position was found: Cover remained in the open position after the second close operation. Therefore a recovery procedure (POINT1_RECOVERY) was suddenly initiated by asking to ESOC-RMOC to run in-real time the following operations: - switch on GIADA by the nominal Power-ON OBCP; - wait few minutes and check the HK telemetry to control the status of the two Reed-switches indicating the open/close Cover position; - switch off GIADA by means of the Power-OFF OBCP with the embedded Close Cover OBCP; - verify the Cover closure by means of the received Cover report and HK telemetry report. At the end of this recovery procedure the Cover resulted successfully closed. In the Pointing Test n. 2 (perforfmed on 30 September 2004), the Rosetta S/C was manoeuvred to get sun light from GIADA –X axis and to change the angle of the sunlight with respect to the S/C +Z axis (which is along GIADA bore-sight) from 20 to 45 deg with steps of 5 deg. Data reported in the present volume are at CODMAC level = 2; therefore they are essentially in the form of physical quantities with units, when appropriate (e.g., voltages in Volts, temperature in Celsius deg), but not converted to yield data in scientific units (CODMAC level = 3). The data set organisation conforms to the Planetary Data System (PDS) Standards, Version 3.0, Jet Propulsion Laboratory (JPL) document JPL D-7669, according to the structure agreed with ESA and described in RO_GIA_OACUPA_IF_011_I3 (reported in DOCUMENTation dir). A general description of GIADA instrument is in RO_GIA_OACUPA_IF_011_I3. See also GIA_GAL_RP_518, GIA_GAL_RP_519, GIA-GAL-RP-520, GIA_GAL_RP_521 and GIA_GAL_RP_522 (reported in DOCUMENTation dir) for evaluations on GIADA behaviour during this mission phase. 2. File Formats See Sections 3 and 4 of RO_GIA_OACUPA_IF_011_I3 (reported in DOCUMENTation dir). 3. Data Set Contents The files on this volume are organized in a directory tree as described in RO_GIA_OACUPA_IF_011_I3 (reported in DOCUMENTation dir). We recall here that GIADA is formed by 3 detection devices: GDS (Grain Detection System), IS (Impact Sensor) and MBS (Micro Balance Sensors), guided and controlled by ME (Main Electronics). We recall that GIADA may operate in four different operative modes. These modes can be selected autonomously by the S/C control system, as well as by means of ground TCs. Different operational modes correspond to different active subsystems, so allowing to measure different quantities, as it follows: Mode Name Active subsystems (nominal) Measured quantities SAFE ME None NORMAL ME, GDS, IS, 5 MBSs Dust flux and fluence Grain Scattering properties Momentum of single grains Velocity of grains Mass of single grains FLUX ME, 5 MBSs Dust flux and fluence COVER ME, Cover or Frangibolt None In each Mode different sensors may also be switched ON/OFF separately by proper TC. While scientific data are acquired in NORMAL or FLUX Modes only, Housekeeping data are acquired in all Modes. We recall that GIADA is a "dust event driven" experiment, so that no scientific data are collected until arrival to the comet. Therefore, during Rosetta Cruise Phase no scientific event is recorded. Actually, some "scientific events" are recorded by GDS and IS, but they are not real dust events and must be neglected. In-flight calibration and housekeeping data are collected and reported in the data set. They are relevant to follow the behaviour and health status of the GIADA experiment and must be used in comparison with data obtained during on ground and other in-flight tests (see other relevant data sets). Under the DATA sub-directory, different sub-sub-directories are present of four main classes. First class: directories containing actual scientific data related to dust monitoring. They are labelled with the acronym of the GIADA sub-system. GDS+IS, GDS and IS directories contain "scientific data" related to "single grain detections" by: GDS_IS (when a grain is detected by GDS and IS in sequence: this is the "nominal" detection of a grain by GIADA); GDS (when a grain is detected by GDS, but the grain momentum is too small to activate the detection by the IS or it does not reach at all the IS); IS (when a grain is detected by the IS, but it was not able, e.g. too small, to activate the optical detection by GDS). If no grain is detected by the relevant sub-system the corresponding directory is not present in the data set. MBS directory contains the periodic reading of each of the five microbalances. Second class: directories containing data acquired for periodic calibration of sub-systems. They are labelled with the acronym of the GIADA sub-system followed by _CAL. Third class: directories containing housekeeping (HK) and instrument status data for instrument health control and verification of behaviour in function of issued commanding sequences. HK_DATA contains HK data acquired periodically, independently on scientific operation of GIADA. These data guarantee a control of GIADA. It also contains a record of GIADA status in terms of operative parameters that are set at the switch on and can be modified by Telecommand during operation. HK_SCI contains HK data recorded contextually to acquisition of "scientific events". These data are useful, for example, to check behaviour of scientific signals with operative conditions (e.g. temperature) and instrument status (e.g.: laser illumination) at the time of event detection. Fourth class: MBS_HEAT contains data acquired when MBS's are heated (this operation is not automatic and is triggered by a suitable Telecommand). This procedure can be activated to try to remove deposited (mainly volatile) material from the sensors in case they should become saturated. Practically, the run of this process is also useful to analyse (periodically) the behaviour of the frequency vs. temperature for each MBS. Under each sub-sub-directory just described, the data are organised in a further lower level according to the date of acquisition and to the kind of test performed on GIADA. Data reported in CALIB sub-dir are of two classes: ENG_CAL: contains data (for Main and Red Interface) for polynomial laws to convert digital numbers (ADC counts) into engineering data with units. Both these data formats are reported in the different data files. SCI_CAL: contains data for transformation of engineering data into scientifically relevant data. These data are not present in the volume. Further details about the data content are reported in the *INFO.TXT files present in each sub-dir. 4.Data Quality At each GIADA switch ON, a careful data analysis is performed to validate data quality with respect to previous on-ground and in-flight switch-on. This check is based on comparison of GIADA housekeeping data and analysis of operation conditions. The quality of GIADA data is identified based on this analysis. The approach is different for data sets at CODMAC 2 or 3 levels and for housekeeping or scientific data. For data at CODMAC 2 level, the data quality convention is as shown below: ID => DESC => Comment 1 => GOOD => All HK and SCI data in the TAB file are good 2 => SPURIOUS EVENTS PRESENT => When only some spurious data are present in the TAB 3 => BAD => A large amount of spurious data is present in the TAB N/A=> N/A => The file contains reference information/data which are not HK or SCI data 5.Errata and Disclaimer A cumulative list of anomalies and errors is maintained in the file ERRATA.TXT at the root directory of this volume, if needed. Although considerable care has gone into making this volume, errors are both possible and likely. Users of the data are advised to exercise the same caution as they would when dealing with any other unknown data set. Reports of errors or difficulties would be appreciated. Please contact one of the persons listed herein. 5. Whom to Contact for Information For questions concerning this data volume, data products, documentation and GIADA in general: Luigi Colangeli INAF - Osservatorio Astronomico di Capodimonte Via Moiariello n. 16 80131 Napoli (Italy) Electronic mail address: giada@na.astro.it, colangeli@na.astro.it Pasquale Palumbo Universita' "Parthenope" Via A. De Gasperi n. 5 80133 Napoli (Italy) Electronic mail address: giada@na.astro.it, palumbo@na.astro.it