converting Dimensions

Use this Forum to find information on, or ask a question about, NASA Earth Science data.
Post Reply
kunal.bali9
Posts: 4
Joined: Tue Sep 26, 2017 9:32 am America/New_York
Answers: 0

converting Dimensions

by kunal.bali9 » Tue Sep 26, 2017 11:56 am America/New_York

Hello,

I have a file with filename MAIACTAOT.h00v02.20000570505.hdf, having the dimensions as

        YDim = 1200;
        XDim = 1200;
The data is only of Indian region. But I don't know the exact coordinates.
Now I need to convert into the latitude and Longitude coordinates. Could anyone please let me know that how can I do that?
please let me know step by step because I am new in SeaDas.

Thank You

Regards
Kunal Bali

Tags:

gfireman
Posts: 64
Joined: Thu Jan 07, 2010 2:59 pm America/New_York
Answers: 0

converting Dimensions

by gfireman » Tue Sep 26, 2017 2:14 pm America/New_York

Where did you get this file?  Doesn't look like one of ours.
The "h00v02" part of the filename suggests it's in a sinusoidal tile grid, as described here.  Except tile "h00v02" doesn't exist, over India or anywhere on the planet.

kunal.bali9
Posts: 4
Joined: Tue Sep 26, 2017 9:32 am America/New_York
Answers: 0

converting Dimensions

by kunal.bali9 » Wed Sep 27, 2017 1:18 am America/New_York

Thanks for the reply.
Somebody has created the 1km aerosol data from MODIS. So, we have collected the data from him (of Indian region). But there is no any proper documentation regarding those file format. I could send one sample file but here, I am not able to attach the file with size more than 1 MB. I have a file with a size of between 1 to 2 MB.

gnwiii
Posts: 713
Joined: Fri Jan 29, 2021 5:51 pm America/New_York
Answers: 2
Has thanked: 1 time

converting Dimensions

by gnwiii » Wed Sep 27, 2017 7:30 am America/New_York

Have you tried compressing the hdf files (e.g., using bzip2)?  That may get you below 1MB.  if not, it would be useful to know if you use SeaDAS (6 or 7) or some other software to work with the data.

Several types of files often use the .hdf extension.  "file MAIACTAOT.h00v02.20000570505.hdf may give:  "Hierarchical Data Format (version 4) data" or "Hierarchical Data Format (version 5) data".  If you are lucky there may be metadata that mentions the map projection details. 

To get started, the most useful thing short of the complete file would be the file metadata in ASCII form.   If you have GDAL, try "gdalinfo <filename>", but note that GDAL often gives bogus corner coordinates for hdf files.  If you have the NASA OCSSW Processing System Installed, use "ncdump_hdf -h <filename>" for version 4,  "h5dump -H <filename>" for version 5.   You should be able to get the same information using  HDFview (version 4 and 5) , MATLAB's  hdfinfo (version 4) or h5info (version 5) and many others.

kunal.bali9
Posts: 4
Joined: Tue Sep 26, 2017 9:32 am America/New_York
Answers: 0

converting Dimensions

by kunal.bali9 » Thu Sep 28, 2017 1:03 am America/New_York

Thanks for the reply and suggestions.
The given file is HDF-4 version. I have compressed the file (804K) but it is not uploading here, showing as an error. So I have attached screenshot of the file.
let me know how can I upload or is there any alternative email address where can I upload the file.

gnwiii
Posts: 713
Joined: Fri Jan 29, 2021 5:51 pm America/New_York
Answers: 2
Has thanked: 1 time

converting Dimensions

by gnwiii » Thu Sep 28, 2017 9:21 am America/New_York

The file is HDF-EOS and does contain the CRS information.   Can you generate a map using Panoply?  If not, the files may not be correct.  SeaDAS 7 has some support for NASA OBPG HDF-EOS files, but I gather it doesn't handle the geolocation for your particular files.  Since your file isn't a NASA OBPG (e.g., SeaDAS 7) product, you need to look elsewhere for software.  The place to look is HDFEOS.org, in particular, the example "zoo".  Another option is to convert your files to GEOTIFF using HEG or to NetCDF-CF using HDF4 CF.

kunal.bali9
Posts: 4
Joined: Tue Sep 26, 2017 9:32 am America/New_York
Answers: 0

converting Dimensions

by kunal.bali9 » Tue Oct 03, 2017 4:46 am America/New_York

I AM ABLE TO GENERATE A MAP USING PANOPLY.

please see the attached file.

Post Reply