Data Set Overview :  Surface Normal for Slopes ------------------------- While the Surface Normal for Slopes product is not archived, it is an intermediate product used as an input to the Solar Energy products, so it is described once here for brevity.  The Surface Normal for Slopes is a unit vector indicating the surface normal for each pixel. It is derived from the XYZ product by fitting a plane over a rover-sized patch in physical space for every image pixel in the input stereo images. The surface normal is then computed (in Site frame) as the normal to the plane fit.  Note that the Surface Normal for Slopes is not the same as the UVW product. While it uses fundamentally the same algorithm, the UVW product is based on a RAT-sized patch and is intended for use with IDD operations, while the surface normal used in slope calculations is based on a rover-sized patch and is intended for use with rover driving. Also, the Slopes version is in Site frame, while the UVW product is expressed in Rover frame.  The symbols Nx, Ny, and Nz are used below to indicate the x,y,z components of the unit vector for slopes.   Solar Energy Map RDR -------------------- The Solar Energy Map RDR is a single-band floating-point image that represents for each pixel the amount of solar energy that would be received by the rover if it were located at the point represented by that pixel. It is expressed as a dimensionless number between 0 and 1, with 1 representing maximum energy. It is computed as the dot product between the Surface Normal for Slopes vector and the Sun Angle:  energy : [cos SA, 0, -cos(90 degrees - SA)] dot [Nx, Ny, Nz]  The Sun Angle is an approximation, usually to the nearest degree. It is a single number indicating the maximum elevation of the sun at local noon. This number is changed periodically (on the order of a few weeks)to follow the movements of the sun during operations, and it differs for Spirit and Opportunity. The Sun Angle used in the calculation is not stored in the label. Therefore the Solar Energy product should be used as a guideline indicating relative amounts of available energy rather than as a calibrated insolation value.  A value of 0.0 is used to indicate lack of data. This can be ambiguous in the rare cases that the computed energy value is exactly 0.0.   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.   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.   Media/Format : The data set will initially be delivered and kept online. Upon Mission completion, the Hazcam Operations RDRs will be delivered to PDS on DVD.

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