Data Set Overview : There are multiple methods of performing radiometric correction,  distinguished by the RADIOMETRIC_CORRECTION_TYPE keyword. The most  common are TAMCAL, RACCAL, MIPLRAD, MIPLRAD2, and MIPLRAD3.  1. TAMCAL Method (SSI Team) This refers to radiometric correction of SSI instrument data only, performed by the SSI instrument team (Texas A&M University and University of Arizona) using their suite of software tools. It is the most precise correction method applicable to SSI data. There are 2 general types of SSI Radiometrically-corrected RDR products that are generated by the SSI instrument team: Radiance-calibrated and Radiance-factor calibrated. Additional details on the radiometric processing and calibration of SSI images can be found in the SSI Calibration Report.  1.1. Radiance-calibrated RDRs ('RAD', 'RAL')  The non-linearized RDRs are generated from EDRs. They have all of the major instrumental/environmental calibrations applied, such as bias removal, dark current removal, electronic shutter smear effect removal, flat field correction, and bad pixel repair. Then they have been scaled to absolute radiance units using pre-flight radiometric calibration coefficients. The units on these files are (W/m^2/nm/sr).  An analogous RDR file type exists for the linearized (geometrically-corrected) SSI RDR as well, and it is labeled with the 'RAL' product type identifier to correspond with the 'RAD' type. In addition, floating point versions of this RDR may also be generated.  1.2. Radiance factor-calibrated RDRs ('IOF', 'IOL')  The non-linearized RDRs are generated from EDRs or 'RAD' RDRs. They have all the major instrumental/environmental calibrations applied and have been scaled to absolute radiance units as described above, and then have been divided by the absolute radiance of the Sun at the top of the Martian atmosphere within the appropriate SSI bandpass, to generate radiance factor, or 'I over F' values, where I is the radiance from the Martian scene and pi * F is the radiance from the Sun at the top of the Martian atmosphere (or on the surface, as determined by reflectance calibration targets. Since the solar radiance in the same units as the Mars scene radiance was divided out, these files are unitless but typically have values in the range of 0.0 to 1.0 (for example, average bright Mars soils exhibit I/F ~ 0.35 at 750 nm and I/F ~ 0.05 at 410 nm).  As with the 'RAD' RDR type, there exists a linearized version of the IOF type of Radiometricallycorrected RDR, called 'IOL'. A floating point version of this RDR may also be generated.  2. RACCAL Method (RAC Team)  This refers to radiometric correction of RAC instrument data only, performed by the RAC instrument team (MPS) using their suite of RACCAL software tools. It is the most precise correction method applicable to RAC data. Note that radiometric correction of MECA-OM instrument data will be performed using the same tools employed for the RACCAL method.  The RAC/OM calibration steps performed by the RACSoft package are described below:  1. The bad pixel removal state replaces a number of pixels marked bad because of dust grains on the CCD or hot electron production. The bad pixels are replaced by an interpolated value based on the surrounding pixels.  2. The bias subtraction state subtracts the ADC digital offset from the image.  3. The RAC and the OM uses an electronic shutter where the image data is fast clocked to a covered aread on the CCD at the end of the exposure. During the fast clocking each row experiences addition light from other parts of the scene. The electronic shutter correction subtracts from row N the summed DN signal of row 0 to N-1 scaled by the time it takes to clock a row one step on the CCD.  4. The dark current correction subtracts an estimated mean value of dark current based on the temperature of the CCD. This simple scheme (as compared to the SSI) is used because the RAC and OM has a very low dark current production under Mars conditions.  5. The flatfield correction divider the image by the relevant flatfield for the given focus motor step.  6. The OM calibration is finished after the flat field correction since good absolute calibration data is not available for the OM.  7. The final step of the RAC calibration is to divide the image by the absolute calibration constant for the given focus motor step. The calibration constant is given by the ground absolute calibration at focus motor step 306 (near infinite focus) and a correction factor derived for the change in instantaneous field of view between focus step 306 and the active focus step.  3. MIPLRAD, MIPLRAD2, MIPLRAD3 Methods These refer to radiometric correction of any camera instrument data  systematically performed by MIPL (OPGS at JPL) to meet tactical time  constraints imposed by Arm Planners. The resulting rad-corrected RDRs are integrated into terrain mesh products used for RA trench  digging. For SSI and RAC instrument data, these methods are less  precise than the TAMCAL and RACCAL methods previously discussed. The  MIPL radiometrically-corrected RDR filenames carry the product type  designators RAD (non-linearized) or RAL (linearized). MIPLRAD, MIPLRAD2, and MIPLRAD3 are first-order corrections only and  should be considered approximate. All three apply the following  corrections: dark current, temperature-compensated responsivity,  exposure time, binning correction, and flat field. The result is  calibrated to physical units for PHX of W/m^2/nm/sr. The actual  algorithm and equations used for the three MIPLRAD's are in the data  product SIS [ALEXANDERETAL2008]. In all cases, ALL_CAPITALS serve to  denote keyword names in the PDS label. The only difference between the three MIPLRAD methods is in the dark  current calculation that is used. MIPLRAD uses a dark current  calculation developed by Adam Shaw at the University of Arizona.  MIPLRAD2 (the default) uses a calculation developed by Mark Lemmon at  Texas A&M University. MIPLRAD3 uses the Lemmon calculation with a  simplification for efficiency (described in the data product SIS). Dark current applies only to SSI. RAC dark current is assumed to be 0  in all three methods. More information is found in ALEXANDERETAL2008, LEMMONETAL2007, and LEMMONETAL2008.  Processing : Phoenix SSI RDRs are considered Level 3 (Calibrated Data equivalent  to NASA Level 1-A), Level 4 (Resampled Data equivalent to NASA Level  1-B), or Level 5 (Derived Data equivalent to NASA Level 1-C, 2 or 3).  The RDRs are to be reconstructed from Level 2 edited data, and are  to be assembled into complete images that may include radiometric  and/or geometric correction. Phoenix SSI instrument EDRs and RDRs will be generated by JPL's  Multimission Instrument Processing Laboratory (MIPL) as part of the  OPGS subsystem of the Phoenix GDS. RDRs will also be generated by  the SSI science instrument team at the SOC facility at the  University of Arizona, as well as at its home institution, Texas  A&M. RDR data products will be generated by, but not limited to, MIPL  using the Mars Suite of VICAR image processing software at JPL, and  the SSI science instrument team using TAMCAL and RACCAL software at  the SOC facility at the University of Arizona and at the team's home  institution at Texas A&M Univerisity. The RDRs produced will be  'processed' data. The input will be one or more Camera EDR or RDR  data products and the output will be formatted according to the data  product SIS [ALEXANDERETAL2008]. Additional meta-data may be added by the software to the PDS label. Data : RDR products generated by MIPL will have a VICAR label wrapped by a PDS label, and their structure can include the optional EOL label after the binary data. RDR products not generated by MIPL may contain only a PDS label. Or, RDR products conforming to a standard other than PDS, such as JPEG compressed or certain Terrain products, are acceptable without a PDS header during mission operations, but may not be archivable. The RDR data product is comprised of radiometrically decalibrated and/or camera model corrected and/or geometrically altered versions of the raw camera data, in both single and multi-frame (mosaic) form. Most RDR data products will have PDS labels, or if generated by MIPL (OPGS), dual PDS/VICAR labels. Non-labeled RDRs include JPEG compressed products and the Terrain products. Software : The MIPL Mars Program Suite was used to generate these RDRs, as well as the TAMCAL and RACCAL software suites. Media/Format : The data set will initially be delivered and kept online. Upon Mission completion, the SSI Operations RDRs will be delivered to PDS  on DVD.

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