topic Re: Define projected coordinate system for MODIS data when area spans 3 utm zones in Geoprocessing Questions

Define projected coordinate system for MODIS data when area spans 3 utm zones

EimearCleary — Thu, 20 Aug 2015 08:06:27 GMT

I'm trying to download and reproject NDVI data to cover Papua New Guinea. However, PNG and the tiles I've downloaded from reverb (Reverb | ECHO ), span 3 UTM zones (UTM 54, 55 & 56). One Modis tile, for example, spans UTM 54 & 55 so I don't know which UTM zone to choose to reproject to.

Has anyone encountered a similar problem or have any idea about a different projected coordinate system I could use for PNG?

I'm using Modis Reproject Tool to convert MODIS files from hdf to geotiff.

Any advice is greatly appreciated.

Thanks!

Re: Define projected coordinate system for MODIS data when area spans 3 utm zones

MelitaKennedy — Thu, 20 Aug 2015 18:22:17 GMT

You could use zone 55. Some transverse Mercator algorithms are only designed for 6-9 degrees from the central meridian, which you're hitting. The algorithm in ArcGIS can support your data's width. However, you're going to see bigger distance and area distortions outside the default zone width of 6 degrees.

You could instead use Mercator (set the standard parallel to -7 or -8, or a conic projection like Lambert, but it would be a custom definition.

Melita