Data Set Overview:MARSIS Level 1b data products consist of the data produced by theinstrument reconstructed from the scientific telemetry, sorted byinstrument state and data type, and provided with spacecraft position,velocity and attitude information.Parameters:MARSIS data are organized into groups of echoes called frames. A framecontains one or more echoes, with or without on-board processing. Eachecho, depending on the kind of processing it underwent, is recordedeither as a time series of signal samples, or as the complex spectrumof the signal itself produced by means of a FFT. Scientific data in aframe are complemented by a set of ancillary data, produced by theinstrument and recording parameter values used in pulse transmission,echo reception and on-board processing.Processing:Level 1b processing starts by cleaning, merging and time-ordering thepackets. Duplicate data are deleted, missing packets are padded out,and the data are organised by orbits. Data are then sorted byinstrument data types and instrument modes, and provided withspacecraft position, velocity and attitude information.MARSIS Level 1b processing orders data in a useful way for theintended users (i.e. radar scientists) and applications (i.e. quicklook to monitor hardware performance and higher-level processing),altering and manipulating them as little as possible to avoid the riskof introducing errors and, at the same time, including all necessaryinformation from all relevant sources. Level 1b data are inscientifically useful form, i.e. individual spectra, but they areuncalibrated.Data:The list of EDR data Products is:E_AIS Active Ionosphere Sounding data frames with geometryinformationE_CAL Data frames acquired in Calibration mode with geometryinformationE_RXO Data frames acquired in Receive Only mode withgeometry informationE_SSx_ACQ_CMP On-board-processed Subsurface Sounding data inAcquisition state, with geometry informationE_SSx_TRK_CMP On-board-processed Subsurface Sounding data inTracking state, with geometry informationWhere 'x' stands for a number between 1 and 5.EDR Data Products consist of two binary files, each of which containsa PDS binary TABLE object, and a single detached PDS label describingtheir structure. The first file, called Frame file (FRM) contains theinstrument data proper, exactly in the same format (bit by bit) asthey were produced by the instrument. Each frame corresponds to arecord in the file, which is also a row in the PDS binary TABLE objectinto which frames are organised.The second file constituting an EDR is called a Geometry file (GEO),and contains one record, corresponding to one line of the PDS binaryTABLE object into which data are organised, for every frame in thecorresponding FRM file. Columns of the table contains the values ofparameters describing the geometry of observation for thecorresponding frame.Ancillary Data:No Ancillary data are provided.Coordinate System:Locations on the surface of Mars are expressed in planetocentriccoordinates. Longitude increases to the East and is comprised in therange 0 - 360 degrees.Software:MARSIS data products can be read by the PDS software NASAView, whichreads a PDS label and displays the associated image or table.Media/Format:The standard distribution format for the data is transfer throughInternet from the Planetary Science Archive of ESA, which can beaccessed at the following URL:http://www.cosmos.esa.int/web/psa/psa-introductionConfidence Level Overview:This data set contains all data for the Mars Express MARSIS for theinterval described above. Every effort has been made to ensure thatall data returned by the spacecraft is included and that processing isaccurate.Review:The MARSIS EDR data have been reviewed internally by the Mars ExpressMARSIS team prior to release to the PDS. The data set has been alsopeer reviewed by the PSA.Data Coverage and Quality:All data in the stated interval are included, to the best of ourknowledge and attempts to determine completeness. The instrument wasoperated only briefly during cruise for periodic instrument health.The late deployment of the MARSIS antenna allowed the start of scienceoperations only six months before the end of the nominal mission.Data quality in a data product label is indicated through theDATA_QUALITY_ID element, and measures the integrity of the telemetrystream from the instrument. The permitted values of DATA_QUALITY_IDare the following:-1: percentage of corrupted data not available 0: no corrupted data 1: less than 2% corrupted data 2: less than 5% corrupted data 3: less than 10% corrupted data 4: more than 10% corrupted dataLimitations:There are no known limitations at this time.

Data quality in a data product label is indicated through the DATA_QUALITY_ID element, and measures the integrity of the telemetry stream from the instrument.