How does satellite imagery improve estimates of crop area?
Satellite imagery has two uses: • to stratify land into land use strata, • to improve estimates of land cover. The first use of stratification has already been discussed. This question will deal with the use of digital satellite imagery to improve estimates of land cover and to reduce survey error. The AF is a perfect tool to provide representative ground data for statistical calibration for atmospheric and growth state. In general, an AF makes estimates of populations based on small samples of segments. Satellite imagery covers an entire population (all sampling units) but the information is not perfect. That is, one has reflected energy at 704 km above sea level for all sampling units in the population. One must use the reflected energy in the satellite imagery in order to reduce the sampling error of the estimates. With AF methods, one has actual ground observations. One uses reflected energy from known fields in order to calibrate the reflected energy. We then classify the entire s
