WHAT IS UTM?
Universal Transverse Mercator (UTM) Projection. A global map projection especially useful for navigation because it preserves angles and compass headings. Area and distance distortions are small. FORMATS: NITF vs. GeoTIFF Although there are many types of imagery formats, the most common now are NITF and GeoTIFF. NITF data contains Rational Polynomial Coefficients (RPCs) in the header file. This allows an end-user to photogrammetrically process in an appropriate software package (SOCET SET, ERDAS Photogrammetry module, etc.). Users can then orthorectify if so desired. GeoTIFF is a very simple stepwise assigning of coordinate values based on a single pixel. Usually the upper left coordinate is assigned a UTM value, knowing the pixel size as 1 or 4 meters, the software assigns a value to each pixel. Users can NOT orthorectify imagery in this format. TIO can reformat data into other formats if needed, for example, GeoTIFF data can be converted and exported as ERDAS Imagine “.
The Uniform Transfer Method (UTM) is not the fifth mechanism. Rather, UTM unifies and simplifies the way in which the four mechanisms are implemented. For example, consider an application that uses UTM to implement primary transfer. To add support for a UTM clipboard transfer, the application programmer need only write a little extra code. That is because UTM makes it easy for the different data transfer mechanisms to share code. As of Motif Release 2.0, all widgets and applications that implement data transfer should use UTM for that implementation. As of Motif Release 2.0, the Motif toolkit implements data transfer exclusively through UTM.
UTM is an acronym for Universal Transverse Mercator, a coordinate system that covers the Earth. The Earth is divided into 60 zones that include 6° of longitude and 8° of latitude. Each zone is divided into a 1 km by 1 km square grid. Coordinates are reported by zone, then easting and northing with respect to the reference grid.
