A vegetation index (also called a vegetative index) is a single number that quantifies vegetation biomass and/or plant vigor for each pixel in a remote sensing image. The index is computed using several spectral bands that are sensitive to plant biomass and vigor. The most common vegetation index is the normalized difference vegetation index (NDVI). NDVI compares the reflectance values of the red and near-infrared regions of the electromagnetic spectrum using the following formula: NDVI=NIR-RED/NIR+RED NIR is the pixel’s reflectence …
What are GPS differential corrections?
Every time a GPS receiver calculates its position, there is some amount of error inherent in the calculated position. Errors can be introduced from a number of sources (e.g., GPS clock errors, atmospheric conditions, the distribution of GPS satellites) over which the GPS user has little control.
Differential correction is a commonly used technique to reduce the systematic errors that decrease the accuracy of GPS positions. All differential correction techniques use correction data from a GPS base station to improve …
What is a spectral signature in remote sensing?
Features on the Earth reflect, absorb, transmit, and emit electromagnetic energy from the sun. Special digital sensors have been developed to measure all types of electromagnetic energy as it interacts with objects in all of the ways listed above. The ability of sensors to measure these interactions allows us to use remote sensing to measure features and changes on the Earth and in our atmosphere. A measurement of energy commonly used in remote sensing of the Earth is reflected energy …
Adventures of the Map@Syst Geocoin
Map@Syst Geocoin Participation
Response to the Map@Syst geocoin was overwhelmingly positive! The geocaching community stepped forward and responded to the call to collectively participate in spreading the word about eXtension resources.
Over 125 coins were sent to 12 countries! Coins are traveling quickly from Cache to Cache. Several have specific goals and missions assigned by the community. We would like to highlight some of the coin travels here and share some of the coin stories.
If you want to see …