MISR L1 and L2 Product Generation Resumes with New Data Product Format

Nov. 6, 2023, 1:53 p.m.

Project: MISR

The change in Terra orbit altitude in October 2022 required a major update to the generation of MISR L1 and L2 products because the spacecraft orbit tracks are no longer tied to a fixed set of 233 WRS-2 paths. L1 and L2 products from October 14, 2022 (orbit 121388) and later will be processed with the updates. Current orbits beginning with 126974 are now publicly available, and past orbits will become available as fill-in processing proceeds.

The products are distributed in NetCDF-4 format, which is compatible with many visualization software tools, including NASA’s Panoply, as well as with common modules in programming languages. Extensive testing shows that product quality is statistically similar to that obtained when the orbit tracks aligned with the WRS-2 paths. Because the map projections are now done dynamically, geographic coverage in v30 has in general improved.

For the time being, products generated prior to orbit 121388 remain unchanged and retain their version numbers. This will be revisited when data from the entire mission are reprocessed to incorporate future product refinements.

For v30 products, the current Browse and Orbit-Path Correspondence tools return incorrect results and will need to be updated. In addition, visualization tools that expect stacked block format (e.g., MINX) will need to be re-released. These updates are in process.

Additional details are available in a set of Powerpoint slides

These and all MISR product offerings are available from NASA’s Atmospheric Science Data Center.

Information about these products and details about product quality are available on the MISR project page

  • Although block number is still used for reference, the customized “stacked block” product structure is eliminated.
  • An improved digital elevation model is used.
  • Filenames retain numerical orbit and path identifiers, with path numbers corresponding to the WRS-2 path closest to the actual orbit track. Because the projected data are not necessarily aligned with the WRS-2 path, the Space Oblique Mercator swath has been widened to avoid truncation of data at the swath edges.
  • All products in the new format are versioned as v30.

Related URLS: https://asdc.larc.nasa.gov/project/MISR