Digital Elevation Mapping for EOS/AM-1 -------------------------------------- The DEM Science Working Group and JPL have produced a draft update of "DEM Auxiliary Datasets Preparation Plan: Digital Elevation Mapping Support to the EOS/AM-1 Platform". The executive summary, invitation for comments, and information to request the full written report is attached. Your comments and input are requested by March 3, 1997. David Goodrich IDS Representative on the DEM Science Working Group Executive Summary The purpose of this document is to provide a Plan for assuring the availability of global Digital Elevation Models (DEMs), associated derived products (e.g. slope; land/water mask, etc.), and software access tools necessary to support the EOS AM-1, TRMM, and Landsat mission's standard product generation. This Plan: 1) Identifies the EOS/AM-1 platform DEM and associated derived/auxiliary products requirement; 2) Provides recommendations for incorporating DEM's into the EOSDIS Core System (ECS) in a timely manner that meets ECS schedules; and 3) Provides a schedule for the development and preparation of DEMs prior to the EOS/AM-1 Platform Launch. The preliminary schedule is provided as Table 6-1. Appendix I provides an overview of the elevation postings and resolution, and Appendix J provides a summary of acronyms used in this document. Signatories of this Plan commit to its implementation on a best effort basis. Based on the DEM requirement discussions in Section 4 and Appendix A, global DEM and DEM/Auxiliary datasets with resolutions of 1 km and 100m should be adequate to support all identified requirements. From the discussions in Secion 5 and Appendix B, it is apparent that the only 100% world-wide database that will be available for unrestricted EOS use by the launch of the AM-1 platform is a 1km resolution DEM. The most complete 100m resolution DEM, which currently comprises 65% of the world's land area, was created by the Dept. of Defense (DOD), but requires special permission (expected in early 1997; with restriction) for general EOS use. An additional 6% of the world is available at 100m resolution for individual instrument team purchase from foreign National Mapping Agencies. In the remaining 35% of the world for which 100m DOD data is not available, DEM dataset preparers have used lower resolution "fill" data. The only significant unrestricted 100m and 30m resolutions DEMs available by AM-1 launch cover the continental USA with 100% and 60% completeness, respectively. The recently approved NASA/DOD Shuttle Radar Topography Mission (SRTM) is expected to provide geographically and topographically consistent world-wide 100m DEMs (+/- 60 degrees Latitude) by early 2000. Other Earth mapping programs are also expected to provide similar resolution DEMs in the Polar (60-90 degrees) regions. However, as any number of unforeseen events could mitigate the SRTM and Polar mission DEM products, EOS users should not assume their potential availability until mission completion and actual production begins, probably in late 1999. Invitation for Comments The purpose of this document is to identify the Digital Elevation Model (DEM) and related auxiliary dataset requirements for all EOS AM-1 platform instruments, and provide a plan that insures the highest quality DEM files available at the time they are needed. As the second draft of the Plan, this document has been extensively updated based on previous comments, recent trade studies, and various events. However, it is expected that there will still be some omissions, discrepancies, misrepresentations and errors. These errors can not be corrected without review. Your comments are requested by March 3, 1997. Thank You for your assistance. If you desire to review the Plan, the full report may be obtained from Thomas L. Logan, Ph.D. NASA/Jet Propulsion Laboratory M/S 168/527 4800 Oak Grove Drive Pasadena, California 91109 e-mail: Tom.Logan@jpl.nasa.gov ph. 818-354-4032 fax 818-354-8982 Review comments should also be forwarded directly to Dr. Tom Logan. _________________________________________________________________ David C. Goodrich USDA-ARS-SWRC Ph. 520-670-6381 (ext. 175) 2000 E. Allen Rd. Fax 520-670-5550 Tucson, AZ 85719 e-mail: goodrich@tucson.ars.ag.gov _________________________________________________________________