Factors to consider when selecting remote sensing products include spatial resolution, spectral resolution, radiometric resolution, and temporal resolution.
Spatial resolution refers to the size of the smallest object that can be detected in an image. The basic unit in an image is called a pixel. One-meter spatial resolution means each pixel image represents an area of one square meter. The smaller an area represented by one pixel, the higher the resolution of the image.
Spectral resolution refers to the number …
Where can I find free aerial imagery?
Aerial imagery can be very useful in the classroom, public meetings, and land management planning and for general historical purposes. Aerial photography is one type of geospatial data that may require a large monetary investment. However, there are sources from which you may be able obtain aerial imagery for your area free of charge.
Most states have participated in national and statewide imagery programs since the middle 1990s (some have been involved even longer). Many of these states provide free …
How can I obtain an aerial or satellite image for my area?
Historic aerial photography (in some cases dating back to the 1930s) is often available from the Natural Resources Conservation Service (NRCS) regional/local office or the Farm Service Agency (FSA) office. Recently acquired aerial photography can often be obtained from your local government (city/county government) office. Contact the local government GIS coordinator. Most cities and larger towns have someone responsible for GIS. If not, then often the planning department, assessor’s office, or engineering department is a good place to get started.…