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GOES-16 Subpoint Correction for
McIDAS-X 2017.2

Summary

The GOES-R Series ABI servers in McIDAS-X 2017.2 have been modified to accommodate an upcoming change to the format of the GOES-16 files distributed in the GRB data stream. The updated servers work with the GOES-16 files being distributed now, as well as those that will be distributed after the data stream change.

The data stream change may occur "as soon as" 03 May 2018. For that reason, we recommend that sites that maintain servers containing netCDF-4 GOES-16 ABI data (mission-standard Level 1b files in netCDF-4 format, like those from NOAA CLASS or decoded from the GRB data stream using CSPP Geo) and users with that netCDF-4 data on their local workstation install the update as soon as feasible so the updated servers are in place before the data stream change occurs. All other users can skip this update.

Details and Instructions

Here is the 04 April 2018 notice about the upcoming data stream changes from NOAA NESDIS:

This is a heads up that ADR 540 will be deployed in the GOES-R Ground System soon by the PRO Team. ADR 540 fixes the nominal satellite subpoint longitude field in the metadata (from -75.0 to -75.2). Please note that the projection longitude values will not change as all products are generated on the fixed grid at 75W. Only the metadata field 'nominal_satellite_subpoint_lon' is changing to represent the actual satellite position at 75.2 W per the Algorithm Working Group (AWG) recommendation.

SSEC's testing of the ABI servers in McIDAS-X 2017.2 (the current release) using NOAA's test files show that the navigation of the images will be incorrect when displaying data from the updated netCDF-4 files. The updated servers (abinadir.cp and abinaget.cp) available here, when installed on McIDAS-X 2017.2 workstations, will work with the netCDF-4 files distributed in the GRB data stream (and available from NOAA CLASS) both before and after the NOAA change is implemented. The updated servers account for the correction in the nominal satellite subpoint (from 75°W to 75.2°W) in the metadata and contain a new variable, pro_lon, that is used in navigation calculations.

Continue with the instructions below to install the updated servers. Note: The instructions apply only to McIDAS-X workstations that are already running version 2017.2. If you are running an earlier version and want to apply this update, you will need to update to 2017.2 and then install these updates. McIDAS-X 2018.1 (planned for May 2018) will also contain these fixes.

Complete the following steps to download, compile and install the updated abinadir.cp and abinaget.cp servers for McIDAS-X version 2017.2.

  1. Log on to the workstation as mcidas.
  2. Change to the source directory for 2017.2 and make backup copies of the existing source files.
      Type: cd  ~mcidas/mcidas2017.2/src
      Type: cp  abinadir.cp  abinadir.cp.bak
      Type: cp  abinaget.cp  abinaget.cp.bak
  3. Download (e.g., right-click and select Save option) the following files to the ~mcidas/mcidas2017.2/src directory on your McIDAS-X workstation.
    File name Size Description
    abinadir.cp 58 KB updated to support GOES-16 file format changes due to addition of nominal subpoint in metadata
    abinaget.cp 120 KB updated to support GOES-16 file format changes due to addition of nominal subpoint in metadata
  4. Change to the ~mcidas directory and run the make option to force a compile of the updated modules (abinadir.cp and abinaget.cp) and their dependencies.
      Type: cd  ~mcidas
      Type: sh  ./mcidas2017.2.sh  make
  5. Run the install option to install the updated modules.
      Type: sh  ./mcidas2017.2.sh  install
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