Earthdata Forum

Dear colleagues,
I would like to know whether there is an option in SeaDas to crop a level 3 mapped image file (in netCDF format) from MODIS by using the spatial information of a shapefile as a reference. The area of interest of my study is defined as a 200 nautical mile (~370.4 km) buffer zone around the coastal outline of La Réunion Island. All land (Mauritius) is excluded. I have a shapefile of the area of interest. The spatial subset function for cropping is not very helpful. Is there a way to indicate the boundaries of the shapefile as a reference for cropping?
I need to crop my files in order to analyze only what is inside my research area and would like to use the statistics tool in SeaDAS for that.
Your help is highly appreciated. Thanks a lot!

The Case Study on SeaDAS Video tutorials has an example creating a mask from a shapefile.  You may want to view the tutorial on masks first. For more than a couple images it is much faster to use the gpt command-line tool's StatisticsOp.  Run gpt StatisticsOP -h for the detailed usage.  You can find examples of gpt xml files on this forum and also the ESA STEP SNAP forum.

Yes, masking is what you are looking for not cropping.  Note that the Statistics tool has masking capabilities.  If it is imagery which you want to mask out, you can do this with the Valid Pixel Expresson.  Of note: SeaDAS 7.5 is coming very soon and has major improvements to the statistiscs tool (both GUI and GPT).

Danny

Dear both, that solved my problem - thank you very much!
What is the planned release date for version 7.5?

It seems to be in late March this year, but I'm not sure :)

Clipping a MODIS Level 3 (L3) file according to a Shapefile refers to the process of extracting a portion of the L3 data that falls within the boundaries of a specific geographic area defined in the Shapefile. The Shapefile is a vector data format that specifies geographic features, such as the outline of a region or country, using points, lines, and polygons.

To clip the MODIS L3 file, the Shapefile is used to define the extent of the area of interest and the L3 data is cropped to match this extent. This results in a new file that only contains data for the specific region defined by the Shapefile, which can be used for further analysis or visualization. Clipping can help to reduce the size of the data and make it more manageable, as well as allowing for more focused and efficient analysis of specific regions of interest.