CCSD3ZF0000100000001NJPL3IF0PDSX00000001 PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 80 OBJECT = TEXT PUBLICATION_DATE = 1994-08-01 NOTE = "MAGELLAN FMAP CUMULATIVE RELEASE NOTES" END_OBJECT = TEXT END COMMENTS ON MAGELLAN FMAP CD-ROMS 1. Purpose of This Document This document is a cumulative summary of comments concerning the Magellan FMAP data set published on CD-ROMs. It contains comments on all the FMAP CD-ROMs published to date. Comments include information of interest to users of the data and notes about any known errors on the CD-ROMs. 2. FMAP Validation Each FMAP product is checked for errors in format and content by a series of programs written at the USGS. In addition, all image files are visually inspected for corrupted data. The results from each volume validation follow. 3. FMAP Volume Validation Results 3.1 Comments on Volume MG_1164, Version 1 This is the first FMAP CD-ROM to be produced. The FMAP products were checked for science quality and no errors or anomalies are reported. Also, no errors are reported from checks using the PDS Label Verifier and Table Browser utilities. However, the files on this volume were not validated by the most recent version of the PDS Data Dictionary. 3.2 Comments on Volume MG_1179, Version 1 The MAP_RESOLUTION keyword value has been changed in the INDEX.TAB, CUMINDEX.TAB, and image labels. Instead of it being an integer value, it is now a real value with four decimal place accuracy. This was done to satisfy the following relationship: (2 * pi * radius / MAP_SCALE)/360 = MAP_RESOLUTION The MAP_RESOLUTION keyword value for volumes MG_1134, MG_1149, MG_1150 MG_1164, and MG_1165 is in error and must be corrected before using. 3.3 Comments on volume MG_1232, Version 1 There are three image files which are missing from directory FL42S042. The three missing images are 47S043.IMG, 47S045.IMG, and 47S047.IMG. These images were omitted because there is no left look coverage in these areas. 3.4 Comments on volume MG_1233, Version 1 There are two image files which are missing from directory FL42S054. The two missing images are 47S049.IMG and 47S055.IMG. These images were omitted because there is no left look coverage in these areas. 3.5 Comments on Volume MG_XXXX, Version 1 The FMAP CD-ROM volume set does not fully comply with PDS map projection standards. The line_projection_offset and sample_projection_offset keywords in the Image_Map_Projection Object of the FMAP products are set opposite to the way they are defined in the Planetary Science Data Dictionary (PSDD). The following equations for converting from lat/lon to line/sample (listed in the DSMAP.CAT file) are also in error: line = INT(LINE_PROJECTION_OFFSET - lat*MAP_RESOLUTION + 1.0) sample = INT(SAMPLE_PROJECTION_OFFSET - (lon - CENTER_LONGITUDE)*MAP_RESOLUTION*cos(lat) + 1.0) The correct equations are as follows: line = INT(LINE_PROJECTION_OFFSET - lat*MAP_RESOLUTION) sample = INT(SAMPLE_PROJECTION_OFFSET + (lon - CENTER_LONGITUDE)*MAP_RESOLUTION*cos(lat)) The value of 1.0 does not need to be added to either equation because the line_projection_offset and sample_projection_offset have already been translated to a (1,1) origin as defined in the PSDD. The equations were originally taken from the MDIM CD-ROM volume set which were not translated to a (1,1) origin. The equation for calculating the sample had a sign change because the direction of positive longitude is East instead of West as it was in the MDIM products. A software patch has been included on this disk to correct the line_ projection_offset and sample_projection_offset keywords on FMAP products. The name of the program is PATCH and it is stored in the SOFTWARE directory. There is a version included for each of the platforms supported by this disk. PATCH is a command line driven program and can be run in either of the two following ways: patch from to patch from The from parameter is the name of an input FMAP image. The to parameter is the name of the output FMAP image with corrected label information. If you do not specify an output image file name, then the program will correct the labels in the input image file. You would probably only want to use both from and to parameters if you are correcting labels of images directly off of the CD-ROM. Please refer to the SOFTINFO.TXT file in the SOFTWARE directory for information on compiling and linking this program for different operating systems. The same commands used to compile and link the software described in that text file were used to create the executeable versions of the PATCH program. 3.6 Comments on Volume MG_1184, version 1. There are 9 image files which are missing from directory FL05n330. The missing images include 01N325, 01N327, 01N329, 03N325, 03N327, 03N329, 05N325, 05N327,05N329. These images were omitted because there is no left look covering these ares.