Finally got CF geostationary projections working, thanks to Tom Rink at SSEC. Click on image to see the big picture:
Here's a picture from another program for comparison (thanks to Randy Horne):
CF geostationary projection now in CDM
29 August 2014
Hi John,
I've been trying out this support for geostationary projection, and I've had success with GOES data (which I specify in the grid variable with sweep\_angle\_axis = "x"). But I haven't had success with Himawari 8 data (sweep\_angle\_axis = "y"). It looks like the pixel locations are just a bit off when computed by the CDM grid mapped projection code. I haven't looked at the code, but do you know if the sweep angle axis functionality is implemented? It does't seem to matter which axis I specify in my Himawari data, I get the same issue.
If it's needed, I put a test dataset at the URL. It contains mostly empty data variables, except the l2p\_flags data which has a land mask as one of the flags. That's how I've been checking accuracy, by comparing against know coastline data. I made a PNG file in the same directory to give you an idea of what I'm seeing when I overlay coastline data, it's over New Zealand and I see an offset of about 5 pixels from the land mask data. It seems the issues in the projection occur diagonally far away from the satellite sub-point lat and lon.
Peter
Posted by Peter Hollemans on October 23, 2018 at 03:55 PM MDT #