# Coordinate system of a MODIS file to be introduced in GDAL for transformation

I am working on MODIS data using GDAL. When I extract coordinate system information of the files I got this: Coordinate System is: PROJCS["unnamed", GEOGCS["Unknown datum based upon the custom spheroid", DATUM["Not specified (based on custom spheroid)", SPHEROID["Custom spheroid",6371007.181,0]], PRIMEM["Greenwich",0], UNIT["degree",0.0174532925199433]], PROJECTION["Sinusoidal"], PARAMETER["longitude_of_center",0], PARAMETER["false_easting",0], PARAMETER["false_northing",0], UNIT["Meter",1]] Origin = (2223901.039533000000000,0.000000000000000) Pixel Size = (926.625433139166600,-926.625433139166720)

I have to transform the coordinate system of my other files into this coordinate system. But the problem is that I don't know how to introduce this coordinate system to my program. I can't find EPSG or Proj4 for it. Any solution or alternative?

I would not recommend using the MODIS sinusoidal projection in analysis. It would be prudent to project your MODIS data to something a bit more tractable. You can request MODIS in a projected geographic (lat/long) coordinate system on the MODIS Golbal Subsets site .

That said I have used this as my CRS for MODIS "+proj=sinu +R=6371007.181 +nadgrids=@null +wktext"

• thank you Jeffery. But I need to download the data from ftp website automatically using a Python program. I need the data stream for my spatial database. I don't think I could do it with the website you introduced. Another question is that if I choose to reproject the data to a well-known coordinate system, does it have significant resampling errors? or I can ignore it? – f.ashouri Nov 2 '12 at 9:49

You can get all the supported coordinate reference system (CRS) used by many GIS applications both on the the desktop environment (ArcGIS, QGIS, Python, GDAL command line, GRASS etc. ) and web, from Spatial Reference. A quick search for MODIS Sinusoidal from the website, will show you all the supported CRS example as shown below:

• Well Known Text as HTML
• Proj4
• OGC WKT
• JSON
• GML
• ESRI WKT
• .PRJ File
• USGS
• MapServer Mapfile | Python
• Mapnik XML | Python
• GeoServer
• PostGIS spatial_ref_sys INSERT statement
• Proj4js format

You can simply copy the text or import files provided on the website to your favourite GIS software application.