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Up Topic SeaDAS / SeaDAS 6.x - General Questions / Seadas 6.2 image display issue (locked)
- By Lide Date 2011-08-02 17:25
1. We have a custom L2 hdf file with longitude and latitude information in it to display in SeaDAS. Both the image data and geolocation data start scan lines from north to south and pixels from west to east. Seadas 6.2 detected the image as generic L2 file and display the image upside-down and left-right-reversed, while the lon and lat is not. Then the landmask will be misplaced by seadas.

2. We then modified the hdf file to trick seadas into thinking it's a MODIS file, it then display both image and lon/lat upside-down and left-right-reversed. The landmask is in place but the whole image is reversed in both directions.

Result 2 seems understandable but result 1 is very weird. I think Seadas should provide users an option how they want their image to be displayed.

Lide
- By sean Date 2011-08-02 18:17
Lide,

SeaDAS' primary purpose is to display and manipulate data products produced by the OBPG.
Recognizing that users may have a desire to display custom products, several years ago we
implemented the 'Generic HDF' option.  Unfortunately, it is not perfect - as you discovered.
The situation you describe, however, should have been handled within the current load routine.
There is an option to reverse the lat/lon arrays - often necessary as IDL reads the data from bottom
up, not top down...Did you check the box in the GUI (or use the img_reverse keyword on the
command line implementation?)

As we are currently actively developing the next version of SeaDAS, there will be no effort
put into improving the current version's ability to navigate generic user created HDF  files.

I apologize if this answer is unsatisfactory to you, but our staff and time are limited.

Regards,
Sean
- By Lide Date 2011-08-03 12:12
thanks for the reply, sean. I have just figured out the display reverse is controlled by hdf_get_ctldata.pro and sdp_read_seamodis.pro under idl_lib. I have modified them to let seadas correctly display the image.
Up Topic SeaDAS / SeaDAS 6.x - General Questions / Seadas 6.2 image display issue (locked)



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