Data Set Overview : This dataset contains data from COSIMA instrument in the Rosetta spacecraft. The set covers the substrate history from the calibration period of the instrument starting 2002-05-29 up to the end of the escort phase 3 2015-10-20. See the MISSION.CAT for a more detailed operations description. During the calibration period the instrument was operated with several software versions and for test purposes the operations were not always nominal. The substrate histories are anyway considered to be complete. During the first commissioning period from 2004-03-02 to 2004-06-06 the substrates from the target holder #D8 covering the dust inlet was stored. During the second commissioning period from 2004-09-06 to 2004-10-16 the first ever in space secondary ion mass spectra were generated. These can be found from the substrate #1C2 data. During the passive payload checkouts (PC) no science data was generated. The target holder #C2 was to be lifted to test the target manipulator unit. This failed in PC1 and PC3 due to hardware anomaly. Due to spacecraft telemetry problem, this history is not available from PC2 either. Test images from empty COSISCOPE slot were taken in all payload checkouts. All the substrates were also imaged in space to be used later as initial reference images. During the active checkouts the main operational concentration was to heal the baddly behaving ion emitter A. During those operations some spectra was acquired, but without intention to generate really scientifically usable background spectra from the substrates. During the prelanding phase, the COSIMA instrument was commissioned. The TOF-SIMS related voltage settings were optimised and COSISCOPE focused using the D8 substrates. From 2014-08-11 onward dust collection and the TOF-SIMS analysis was carried out with the D0 substrates. The TOF-SIMS measurements were done on selected dust particles on all D0 substrates. The particles coordinates were established manually from the COSISCOPE images. The substrate coordinate system applied for the TOF-SIMS has some extra offsets due to mechanical tolerances, particle heights and ion paths being different for positive and negative SIMS. These offsets can only be established by analysing the TOF-SIMS and image data. As of 2014-10-23 the ion optics was not operable anymore within the nominal operation parameter settings and the TOF-SIMS and the spectra got scientifically useless. The TOF-SIMS data during the 2014-10-23 - 2015-03-10 period is more or less instrument test data. Some of the tests were done across particles and the data may be usable, but the spectra are out of the nominal parameter range, containing shadow peaks and instrument effects. While the instrument was tested with different ion optics parameter setups, the CF substrates were exposed first time to collect dust on 2014-12-12. The particle collection worked nominally. The C7 substrates were exposed for the first time on 2015-02-14. From middle of the March 2015 a parameter setup was established, that recovered the TOF-SIMS part of the instrument. Searching for a new ion path optimum was a slow process, as there was the potential of permanent damage due to Indium deposition on ion optics. The SIMS was carried out mainly with C7 and CF. D1 was exposed on 2015-04-10 and CD on 2015-05-30. CD, CF and D1 were analysed by TOF-SIMS during May 2015 and CF and D1 in the June 2015. In July 2015 C7 was measured again, while CD was exposed for particle collection and TOF-SIMS up to October. D2 was exposed on 2015-10-11. Parameters : The primary measured parameter is the time of flight mass spectrum of a grain, ion events collected for 131072 time bins, each 1.953125 ns in length. For data selection purposes, three individual time windows can be selected for each generated spectrum. In addition or instead, a peak list separating the organic and inorganic peaks can be generated. For quantitive analysis and gain optimisation, instead of individual time bins, a sum of events in three time windows can be collected. These are called scans in the COSIMA system. Grains in the substrate are searched from the COSISCOPE images. Although COSISCOPE can generate the grains list on board, most of the grain analysis is done manually on ground from the images. Processing : The spectrum time of flight ion data is mass calibrated with the same procedure as is used in space for the peak data. The calibration should be used only as rude starting point and for scienctific analysis each calibration must be checked. The housekeeping data covering the data aqcuisition period is calibrated to physical units and statistically analyzed were applicable to support the evaluation of the data quality. Data : COSIMA generates the following PDS products history ------- The substrate history product contains information about substrate storage and expose periods, cleaning and heating actions, COSISCOPE camera images and grains lists and any spectra taken. The history starts from the moment substrates were installed in the COSIMA flight instrument. The product files have the naming convention CS_YXX_SUBSTRATE_HISTORY.TAB, where the Y is either 1 for top, 2 for middle and 3 for bottom substrate. The XX is target holder number in the range C1 to D8, counting in hexadecimal number base. Note that although there is an action entry in the table, the spectrum, image or housekeeping data may be marked as missing, usually due to telemetry downlink problems. spectrum -------- The spectrum is generated by bombing the comet grains collected on the substrate by indium ions. The seconday ions are measured by time of flight mass spectrometer. The spectrometer collects individual ion arriving times to an array of 131072 bins, each 1.953125 nanosecond in size. From accumulated ion data, peaks are detected and from the assumed mass scale and detected peak positions a mass is given to each time bin. This calibration is automatic and the user must check the scale for real use. The position given as X and Y does not necessarily match the X and Y established on the substrate image due to mechanical and ion path reasons and differs for the positive and negative data. This offset can only be solved by analysing the TOF-SIMS data. The spectrum can be divided in time to at most tree different subspectrums to reduce the amout of data to be transmitted. The product files have the naming convention CS_YXX_YYYYMMDDTHHMMSS_SP_Z.TAB, where the Y is either 1 for top, 2 for middle and 3 for bottom substrate. The XX is target holder number in the range C1 to D8, counting in hexadecimal number base. The YYYYMMDDTHHMMSS gives the start year, month, day, hour, minute and second. The Z is P for positive and N for negative ion spectrum. peaks ----- Generated as the spectrum, but the spectrum mass scale is established onboard COSIMA. The list of 300 first organic and inorganic peaks is transmitted. For higher masses, the total of count hits for a mass range is given. For the definition of the peak separation see the EAICD document. The product files have the naming convention CS_YXX_YYYYMMDDTHHMMSS_PK_Z.TAB, where the Y is either 1 for top, 2 for middle and 3 for bottom substrate. The XX is target holder number in the range C1 to D8, counting in hexadecimal number base. The YYYYMMDDTHHMMSS gives the start year, month, day, hour, minute and second. The Z is P for positive and N for negative ion spectrum. scan ---- Used for instrument calibration, gain optimisation or when moving over the substrate, to make a measurement matrix. Produces total sum of the event counts over three possible time windows. The product files have the naming convention CS_YXX_YYYYMMDDTHHMMSS_SCAN.TAB, where the Y is either 1 for top, 2 for middle and 3 for bottom substrate. The XX is target holder number in the range C1 to D8, counting in hexadecimal number base. The YYYYMMDDTHHMMSS gives the start year, month, day, hour, minute and second. The Z is P for positive and N for negative ion spectrum. heat ---- The substrate can be heated to clean it or to analyse volatile dust. The product contains the heating curve. The product files have the naming convention CS_YXX_YYYYMMDDTHHMMSS_HEAT.TAB, where the Y is either 1 for top, 2 for middle and 3 for bottom substrate. The XX is target holder number in the range C1 to D8, counting in hexadecimal number base. The YYYYMMDDTHHMMSS gives the start year, month, day, hour, minute and second. The Z is P for positive and N for negative ion spectrum. clean ---- The single substrate position can be cleaned by the Indium ion beam. The product contains the emitter tip current housekeepin statistics. The product files have the naming convention CS_YXX_YYYYMMDDTHHMMSS_SCAN.TAB, where the Y is either 1 for top, 2 for middle and 3 for bottom substrate. The XX is target holder number in the range C1 to D8, counting in hexadecimal number base. The YYYYMMDDTHHMMSS gives the start year, month, day, hour, minute and second. The Z is P for positive and N for negative ion spectrum. Note that so far this have never been done in with the COSIMA. spectrum housekeeping --------------------- There's three kind of housekeeping information. First, the minimum, maximum, mean and standard deviation of the analog data, temperatures, voltages and currents, is calculated for the period of the measurement. Second, the used time to digital converter timing for the ion beam chopper, bunchers and ion optics is given. Third, the time to digital converter temperature calibration for the delay line is given. The calibration is needed to adjust the delay line so, that the 16 bin hardware event counter gets even bin distribution over the sampling period. The product files have the naming convention of either CS_YXX_YYYYMMDDTHHMMSS_S_HK.TAB for spectrum, CS_YXX_YYYYMMDDTHHMMSS_SCHK.TAB for scan or CS_YXX_YYYYMMDDTHHMMSS_CLHK.TAB for cleaning, where the Y is either 1 for top, 2 for middle and 3 for bottom substrate. The XX is target holder number in the range C1 to D8, counting in hexadecimal number base. The YYYYMMDDTHHMMSS gives the start year, month, day, hour, minute and second. grains ------ The grain list is taken by the COSISCOPE camera from the substrate surface. The orientation of the substrate is calculated from the reference dots on target holder. The binding box of the substrate feature is given in substrate coordinates, which has origo at lower left corner and is 10000 times 10000 micrometers. The grain quality, based on the brightness is given as relative number from 0-255. The product files have the naming convention CS_YXX_YYYYMMDDTHHMMSS_GR__.TAB, where the Y is either 1 for top, 2 for middle and 3 for bottom substrate. The XX is target holder number in the range C1 to D8, counting in hexadecimal number base. The YYYYMMDDTHHMMSS gives the start year, month, day, hour, minute and second. Note that there are calibration images and thus calibration grain lists, which can be identified from a fixed pattern, typically with 103 detected grains. Note that consecutive grain lists may have different content due to variations in the mechanical positioning and illumination. image ----- The image take by the COSISCOPE camera. The image has 1024*1024 pixels resolution with 10 bit brightness information. The PDS product uses 16 bits for brightness storage. The product files have the naming convention CS_YXX_YYYYMMDDTHHMMSS_IM_Z.LBL, where the Y is either 1 for top, 2 for middle and 3 for bottom substrate. The XX is target holder number in the range C1 to D8, counting in hexadecimal number base.The YYYYMMDDTHHMMSS gives the start year, month, day, hour, minute and second. The Z is P for right (plus) side and M for left (minus) side led illumination. The LBL file points to simlarly named FIT file, where the FIT refers to the FITS image standard. FITS (Flexible Image Transport System) format is defined in 'Astronomy and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359 Note that there are calibration images, which can be identified from a fixed squares pattern. COSISCOPE housekeeping ---------------------- For the COSISCOPE housekeeping the operating temprature mimimum, maximum, mean and standard deviation is calculated for the operation time period. In addition, the COSISCOPE operation setup parameters are given. Also the subsrate orientation information is given and the mask used to pick up subimages. The product files have the naming convention CS_YXX_YYYYMMDDTHHMMSS_G_HK.TAB, where the Y is either 1 for top, 2 for middle and 3 for bottom substrate. The XX is target holder number in the range C1 to D8, counting in hexadecimal number base.The YYYYMMDDHHMMSS gives the start year, month, day, hour, minute and second. Ancillary Data : Other data required to interpret this data, especially if it is not included in the dataset (for example, laboratory calibration values) Coordinate System : COSIMA substrates are exposed 3 at a time to the +Z side of the spacecraft. The dust funnel has a 13 * 20 degree field of view for a distinct dust particle. ^ | direction of | flight | ^ +Xcosima (down-track) | | --- +---------|---------+ ^ | | | | | | | | | | | | | | | | 13 deg | x-------------> +Ycosima (cross-track) | | +Zcosima | | | | | | | V | | --- +-------------------+ | 20 deg | Boresight (+Z axis) |<----------------->| is into the page | | The distance from the funnel inlet to the exposed (10+1+10+10)mm*10mm substrates is 162 mm. The dimensions of the funnel inlet are 58mm*40mm. ------------- ----------------- ^ ------------ 20 5 v <------------------ 162 -----------------> 5 ^ ------------ 20 ----------------- v ------------- ------------- ----------------- ^ ------------ 29 16 v <------------------ 162 -----------------> 16 ^ ------------ 29 ----------------- v ------------- No S/C geometry is calculated for the data. The substrates have a coordinate system, defined in micrometers from 0-10000 in X and Y direction, starting from the lower left corner. There's a second coordinate system, named XM substrate in the FITS-file, which tries to compensate on the mechanical and ion path difference from the COSISCOPE to the TOF-SIMS analysis position. The spectrum position given as X and Y does not necessarily match the X and Y established as XM substrate coordinates. This offset is different for positive and negative spectra and can only be solved by analysing the TOF-SIMS data. Software :All the data can be used by PDS tools or any ASCII reading software. Media/Format : The data is delivered as PDS standard compliant electronic files.

Confidence Level Overview : The data have been automatically processed from raw data. Care should be taken in spectrum analysis, the housekeeping values for operating voltages should be checked for possible anomalies. Some of the operations during the calibration were really outside of normal instrument operation. The mass scale of the specra is automatically calculated on board COSIMA and is not valid for scientific analysis. The spectrum measurement XY position on the substrate has an offset due to ion path and mechanical position inaccuracy. It's also different for positive and negative spectra. Review : The dataset review is available from the RO-EST-RP-3461, ROSETTA Science Archive 1st Delivery Review Report for Orbiter instruments (15 March 2007). This covers the dataset v1.0, where there was no spectrum mass scale. Data Coverage and Quality : The data covers the COSIMA flight model operations from the flight substrate delivery 2002-05-29 to the end of the escort phase 3 2015-10-20. The production of the substrates is not part of the substrate history. Regardless of the several anomalies in the instrument operations during the calibration period, the substrate histories are complete. Limitations : Housekeeping data outside spectral measurements and COSISCOPE operations is not delivered. This would include indium ion emitter history and target manipulator operations. Though vital to the instrument operations, they are not needed in the scientific interpretation of the COSIMA data.