Satellite Imagery
We supply imagery from a wide range of suppliers, including space agencies, traditional industry-leading commercial organizations and innovative companies, covering respectively the highest resolution imagery available from space, and imagery from new super-sampling constellations of satellites. While we supply traditional visible imagery we also offer radar imagery that can be used to observe the surface during night and cloudy conditions, and other advanced sensors that have been designed for the most advanced applications.
Geomap offers access to imagery from more image suppliers than anyone else, at no extra cost to you through using our services, providing you with access to a very wide range of competitively priced image types and resolutions.
Specifications
Spatial Resolution
The spatial resolution specifies the pixel size of satellite images covering the earth surface.
Low Resolution Satellite Imagery
Low resolution satellite imagery is a great option for those needing imagery of large areas, such as states, provinces or entire countries. These sensors offer complete world coverage at a low cost per square kilometer, making it an excellent choice for those needing a simple base map. While this imagery is a bit too coarse to identify individual buildings, one can still generally see changes in landscapes, roads, and bodies of water.
Medium Resolution Satellite Imagery
Geomap offers a large archive of satellite imagery collected between 1.5 meter–5 meter resolution. Each provider of these resolutions has multiple sensors in each satellite constellation, and each satellite collects large areas within one image. As such, one has the best chance of finding recent data of his or her area from a satellite in this product suite. A massive archive with full world coverage exists as well.
High Resolution Satellite Imagery
Geomap offers an extensive selection of the highest resolution satellite imagery commercially available. Our vast archive includes imagery from all leading providers. With so many different options available, we can offer high resolution imagery for nearly any place on Earth. Resolutions for the sensors in this section range between 0.3 meter (the highest commercially available) to 1 meter.
Spectral Resolution
In the first instance, a sensor's spectral resolution specifies the number of spectral bands in which the sensor can collect reflected radiance. But the number of bands is not the only important aspect of spectral resolution. The position of bands in the electromagnetic spectrum is important, too.
High spectral resolution: - 220 bands
Medium spectral resolution: 3 - 15 bands
Low spectral resolution: - 3 bands
Resolution Trade-Off
The different spatial, temporal and spectral resolutions are the limiting factor for the utilization of the satellite image data for different applications.
Unfortunately, because of technical constraints, satellite remote sensing systems can only offer the following relationship between spatial and spectral resolution: a high spatial resolution is associated with a low spectral resolution and vice versa.
That means that a system with a high spectral resolution can only offer a medium or low spatial resolution.
Therefore, it is either necessary to find compromises between the different resolutions according to the individual application or to utilize alternative methods of data acquisition.
The trade-off may result in two different solutions:
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To lay emphasis upon the most important resolution, in direct dependency to the application, with the acceptance of low attendant resolutions at the same time, or
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To lay no emphasis on one specific resolution and at the same time the acceptance of a medium spectral, temporal and spatial resolution.
