This way of transferring from one coordinate system to another works with any map projection supported by IDL. Since UTM coordinates are nothing more than projected meters. IDL> Print, mapCoord.Inverse(491539.11, 4494148.3)Ĭonverting from one coordinate system to the other is as simple as that. To go from UTM coordinates to latitude/longitude, you simple use the inverse transformation in a similar way. Suppose, you want the UTM coordinates for Fort Collins. Then, if you want to convert latitude/longitude to UTM coordinates, you simply perform a forward map transformation, using the Forward method of the map coordinate object. You simply do this, where myGeoTiffFile is a string variable containing the name of your GeoTiff file. If you are working with an image, and the image is in a GeoTiff file, then creating the map coordinate object is even easier. Or, if you have IDL 8 or higher, like this. In other words, the same UTM coordinate will give slightly different latitude and longitude values, depending upon the ellipsoid you are using to calculate these values. Will be determined by the datum or ellipsoid you use. This is normally WGS84 for satellite data. Use the correct ellipsoid for the data you are working with. So, to create a map projection space using this UTM zone, you would create the map coordinate object like this. You can find the UTM zone in this area like this. Fort Collins is atĤ0.6 degrees North and 105.1 degrees West. Suppose, for example, you wanted to convert from UTM coordinates to latitude/longitude coordinates in the area of Fort Collins, Colorado. But, if you have a latitude and longitude value, you can use the Coyote Library routineĬgUTMZone to return the correct zone number. Normally, the only hard thing about this is knowing what UTM zone you want. The only "trick" (if there is one), is to set up the UTM map projection space correctly. You can set the map projection up with Map_Proj_Init and then use Map_Proj_Forward and Map_Proj_Inverse to do the transformations, or you can simply use the cgMap object from the Coyote Library, which will do the transformations for you with its Forward and Inverse methods. This is simply a forward (lat/lon to UTM) and/or inverse (UTM to lat/lon) transformation of a map projection. NOTE: A different (more thorough and harder to understand) treatment of this topic can be foundĪNSWER: You don't need software to do this. I'm going crazy looking all over the Internet for software to do this. Then, I want to be able to convert an east/north UTM coordinate into a latitude/longitude coordinate. QUESTION: Do you have any software to convert backĪnd forth between UTM and latitude/longitude coordinates? I want to specify a latitude and longitude and have it converted to an east and north UTM coordinate. Coyote's Guide to Traditional IDL GraphicsĬonverting Between UTM and Latitude/Longitude Coordinates.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |