ABSTRACT
Several common projection systems used in digital remote sensing of natural resources include the Mercator Projection, the Transverse Mercator Projection, and the Space Oblique Mercator Projection. There are three common coordinate systems used in the United States for satellite remote sensing of natural resources: geographic coordinates, Universal Transverse Mercator coordinates, and State Plane coordinates. Ground control points are locations that can be delineated on a satellite image and on a corresponding map coordinate system. In fact, surveyors use very expensive Global Positioning System (GPS) receivers and differential positioning to record locations with an accuracy tolerance of less than 1 cm. There are several limitations of using GPS in determining ground control location map coordinates. Cubic convolution resamples pixels as a weighted average of the 16 nearest original data values; therefore it takes much longer to rectify an image with cubic convolution resampling when compared with nearest neighbor or bilinear interpolation resampling.
