DATA_SET_DESCRIPTION |
Data Set Overview:JIRAM Level 1b data products consist of the data producedby the instrument reconstructed from the scientific telemetry,sorted by instrument state and data type, and providedwith spacecraft position, velocity and attitude information.Any other spacecraft telemetry relevant for calibration andprocessing (e.g. temperature of the receiver) is also be included.JIRAM data consist of two parts: the first contains ancillary dataproduced by instrument and used to interpret scientific data, thesecond is science data.The scientific products are spectra or images that are downloadedform the S/C in data packets or sub-frames.Packets are then recombined by IOT in image or a number ofspectra as function of the used submode.Data organized in submodes are not compressed.Compression on the data is possible to reduce the data volume.Lossy compression is possible on imager data; the images can bereduced to JPEG format. The lossy compression reduces the images datavolume of a factor 6.Lossless compression can be applied to spectra.The lossless compression would produce a compression of a variablefactor that depends on the datum itself. The factor is about 1.5 onaverage.For each Data Set JIRAM team will deliver a spreadsheet containingauxiliary information.In each spreadsheet all products are ordered by acquisition time.This file will give an overview on the data set acquisition.Data:The 'JUNO MOON JIRAM EXPERIMENT DATA RECORD V1.0' Data Setcontains scientific telemetry generated by the instrument,edited to remove duplications, zero-padded for missingpackets, and correlated with geometric information needed to locateobservations in space and time. No other kind of processing isapplied to the data.Coordinate System:Locations on the surface of JIRAM are expressed in planetocentriccoordinates. Longitude is comprised in the range 0 - 360 degrees.Data Quality: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: complete data 0: incomplete data
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CONFIDENCE_LEVEL_NOTE |
Confidence Level Overview :JIRAM status and capabilities have been tested on October 9, 2013 duringthe Juno's Earth flyby when the instrument targeted the Moonfor about half an hour.Beyond the scientific value of the observation, this has been so farthe first and unique occasion during the cruise phase to verify the executionof the science observing sequences as they will be operated at Jupiter.The imager has been able to capture the Moon region straddlingthe terminator in L and M astronomic bands.Some surface features are recognizable and have been mapped withthe support of the geometric information available for JIRAM data.Spectral pixels acquired in parallel with the M image have beenused to retrieve temperature and spectral emissivity of the sounded region. Data Coverage and Quality :During the Juno's Earth fly-by, on October 9, 2013, instruments wereswitched ON the for their status and responsivities checking.While the S/C was moving towards the Earth, JIRAM was active,targeting the Moon, since 13:05 up to 13:50 UTC about.Throughout this time period the spacecraft moved along its counterclockwiseSun orbit passing between Earth (on the left) and Moon (on the right).In the pass geometrical configuration, the Sun was approximatelyin the opposite direction of the spacecraft motion versus and the Moon,at the Juno's closest approach, was divided in two halves by the terminator.In this configuration JIRAM's telescope swept the body that appearedas entering in the image plane from the left and crossingit towards the right side.132 images both for science and calibrations both in L and M bandswith an equivalent amount of spectral measurements have beenproduced in this 45-minutes acquisition.Among those targeting the Earth's satellite, some of them have beenchosen for a preliminary analysis.There is not any particular reason in the choice as in the short periodof observations the sounded region at the terminator practicallydid not experience variations. Data Coverage and Quality : All data in the stated interval are included, to the best of our knowledge and attempts to determine completeness.
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