Monthly Archives: February 2008

There are several ways to classify the wide variety of map projections. One of the most common classifications is by distortion characteristics: which properties of the Earth does the projection maintain? Which does it distort? Classification based on distortion characteristics … Continue reading →

A map projection is a way to represent the curved surface of the Earth on the flat surface of a map. A good globe can provide the most accurate representation of the Earth. However, a globe isn’t practical for many … Continue reading →

1759 First statements by Lambert (France) of principles underlying photogrammetry 1839 First ever photographs by Daguerre and Nepce, in France 1840 French used photos in making topographic maps. 1850’s Photographs important in documenting exploration of the U.S. West (through 1870’s). … Continue reading →

NDVI is the acronym for normalized difference vegetation index. It is a simple formula using two satellite channels. If one band is in the visible region (VIS, for example AVHRR band 1) and one is in the near infrared (NIR, … Continue reading →