Data Set Overview : The MIPLRAD method refers to radiometric correction systematically performed by MIPL (OPGS at JPL) to meet tactical time constraints imposed by rover planners, since these RDRs are integrated into terrain mesh products used for traverse planning. The method can apply to any of the camera instruments. In the operations environment for the Prime and Extended Missions, MIPL's radiometrically-corrected RDR filename carries the product type designator of RAD for the non-linearized case and RAL for the linearized case. However, in the PDS archive volume, the MIPL radiometrically-corrected RDR carries the product type MRD for the non-linearized case and MRL for the linearized case. Though there is no difference in image content between the operational and archived versions of MIPL's radiometrically-corrected RDR, the distinction in their filenames is made to identify all RAD and RAL product types in the PDS archive volumes as being unique to the Athena Pancam team's radiance correction process. As a special note, two bugs pertaining to MIPL's radiometric correction process were discovered during the preparation of data for PDS archival, which was after the MER Prime Mission and well into the Extended Mission. The problems involved on-board flat-field removal and temperature determination. For the purposes of this discussion, the term MIPLRAD refers to the original implementation used during Prime Mission and approximately through the first two months of Extended Mission, while MIPLRAD2 represents the corrected implementation used thereafter. Both MIPLRAD and MIPLRAD2 are valid values for RADIOMETRIC_CORRECTION_TYPE. The differences are described below. Note that all RAD/RAL/RSD/RSL types of RDRs have been reprocessed with MIPLRAD2, limiting the number of MIPLRAD-processed products in the PDS archive volume to a subset of mosaics which were generated before MIPLRAD2 was implemented. Note also that no mosaics were generated from on-board flat-field images using MIPLRAD, so the only difference in the archive data is the temperature issue. MIPLRAD is a first-order correction only and should be considered approximate. MIPLRAD first backs out any onboard flat field that was performed. It then applies the following corrections: flat field, exposure time, temperature-compensated responsivity. The result is calibrated to physical units for MER of W/m^2/nm/sr. The actual algorithm and equations used for MIPLRAD are shown below. Each correction is applied in sequence, to every pixel: 1. If on-board flat-fielding has been applied, it is backed out according to the parameters in FLAT_FIELD_CORRECTION_PARM, which defines ff(x,y). MIPLRAD incorrectly multiplied by ff(x,y) rather than divided, causing the on-board flat field to be doubled rather than removed. MIPLRAD2 correctly divides by ff(x,y) as follows: output(x,y) : input(x,y) / ff(x,y) 2. For the flat-field adjustment, the x and y coordinates are adjusted based on downsampling and subframing to find the corresponding pixel in the flat field, then the DN is divided by the flat field value: output(x,y) : input(x,y) / flat_field(x',y') 3. Exposure time is then removed. Exposure time comes from EXPOSURE_DURATION, converted to seconds: output(x,y) : input(x,y) / exposure_time 4. The temperature responsivity is removed next. The temperature comes from the first element of INSTRUMENT_TEMPERATURE and the parameters R0, R1, and R2 come from the flat field parameter file, and are different per instrument. The actual temperature formula is as follows: output(x,y) : input(x,y) * (R0 + R1*temp + R2*temp*temp) For MIPLRAD, the temperature is simply the first element of INSTRUMENT_TEMPERATURE. For MIPLRAD2, the temperature is dependent on the instrument. The temperature used for each instrument is determined using the following general rules (from the MER thermal team): a) Use the CCD temp of said camera, if it exists. b) Use the CCD temp of neighboring camera (left/right partner), if available. c) Use the CCD temp of similar camera (i.e., Navcam/Pancam). d) Use CCD temperature from any camera. e) Use the electronics temperature of said camera. f) Use the electronics temperature of similar camera. Rules e and f are a last resort in view of the fact that MER operates warmup heaters inside the electronics (during nighttime and early morning) that raise camera electronics temperatures above CCD temperatures. Thus any CCD temperature is at higher priority than any electronics temperature measurement. The most significant consequence of this is that the MI CCD is the best available proxy for all four Hazcam CCDs. A value of 0.0 is ignored as a no-reading value, and a value greater than or equal to 50.0 (degrees C) is interpreted as a broken sensor. Either value causes that temperature to be ignored and the next one on the list tested. If none of the values is valid, a default of 0.0 degrees C is used. Processing : MER Camera Payload 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. MER Camera Payload EDRs and RDRs will be generated by JPL's Multimission Image Processing Laboratory (MIPL) under the OPGS subsystem of the MER GDS. RDRs will also be generated by the Athena Pancam Science and Microscopic Imager Science Teams under the SOAS subsystem of the GDS. RDR data products will be generated by, but not limited to, MIPL using the Mars Suite of VICAR image processing software at JPL, the Athena Pancam Science Team using IDL software at Cornell University and JPL, and the Microscopic Imager Science Team using ISIS software at USGS (Flagstaff) and JPL. 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 this SIS. Additional meta-data may be added by the software to the PDS label. There may be multiple versions of a MER Camera RDRs. 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. The MIPLRAD method is a radiometric correction performed by MIPL (OPGS) at JPL. It can apply to any of the camera instruments, but only the RAD (and RAL) type is generated. MIPLRAD first backs out any onboard flat field that was performed. It then applies the following corrections: flat field, exposure time, temperature-compensated responsivity. The result is calibrated to physical units for MER of W/m^2/nm/sr. MIPLRAD is a first-order correction only and should be considered approximate. Software : The MIPL Mars Program Suite was used to generate these RDRs. Media/Format : The data set will initially be delivered and kept online. Upon Mission completion, the Microscopic Imager Operations RDRs will be delivered to PDS on DVD.

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