TYPES OF REMOTE SENSING SENSORS PDF DOWNLOAD!
Remote Sensor Types. Remote sensor types are the platforms that acquire imagery or other measurements of the earth's surface. They can be satellite-, aircraft-, or ground-based. Most Remote Sensing Methods can be applied to more than one sensor type and sometimes many types. Overview. Remote sensing instruments are of two primary types—active and passive. Active sensors, provide their own source of energy to illuminate the objects they observe. An active sensor emits radiation in the direction of the target to be investigated. There are several types of sensors that are used in remote sensing satellites. These sensors vary according to the purposes for which they are used. Main type.
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For example, the moon is a natural satellite, whereas man-made satellites include those platforms launched for remote sensing, communication, and telemetry location and navigation purposes.
Salient feature of some important satellite platforms. Passive sensors detect the reflected or emitted electro-magnetic radiation from natural sources, while active sensors detect reflected responses from objects which are irradiated from artificially generated energy sources, such as radar.
Each is divided further in to non-scanning types of remote sensing sensors scanning systems.
Passive vs Active Sensors in Remote Sensing
Cloud cover over a given area or object makes it necessary to repeat the collection of said location. In order to create sensor-based maps, most remote sensing systems expect to extrapolate sensor data in relation to a reference point including distances between types of remote sensing sensors points on the ground.
This depends on the type of sensor used. For example, in conventional photographs, distances are accurate in the center of the image, with the distortion of measurements increasing the farther you get from the center.
Another factor is that of the platen against which the film is pressed can cause severe errors when photographs are used to measure ground distances. The step in which this problem is resolved is called georeferencingand involves computer-aided matching of points in the image typically 30 or more points per image which is extrapolated with types of remote sensing sensors use of an established benchmark, "warping" the image to produce accurate spatial data.
- Sensors Used in Remote Sensing
- Types of Sensor
- Passive vs Active Sensors in Remote Sensing - GIS Geography
- Remote Sensors
As of the early s, most satellite images are sold fully georeferenced. In addition, images may need to be radiometrically and atmospherically corrected.
Radiometric correction Allows avoidance of radiometric errors and distortions. The illumination of objects on the Earth surface is uneven because of different properties of the relief.
This factor is taken into account in the method of radiometric distortion correction.
Remote sensing - Wikipedia
Topographic correction also called terrain correction In rugged mountains, as a result of terrain, the effective illumination of pixels varies considerably. In a remote sensing image, the pixel on the shady slope receives weak illumination and has a low radiance value, in contrast, the pixel on the sunny slope receives strong illumination and has a high radiance value.
For the same object, the pixel radiance value on the shady slope will be different from that on the sunny slope. Additionally, different types of remote sensing sensors may have similar radiance values.
Remote Sensor Types 
These ambiguities seriously affected remote sensing image information extraction types of remote sensing sensors in mountainous areas. It became the main obstacle to further application of remote sensing images.
The purpose of topographic correction is to eliminate this effect, recovering the true reflectivity or radiance of objects in horizontal conditions. It is the premise of quantitative remote sensing application.
Atmospheric correction Elimination of atmospheric haze by rescaling each frequency band so that its minimum value usually realised in water bodies corresponds to a pixel value of 0. Sounder —An instrument that measures vertical distributions of atmospheric parameters such as temperature, pressure, and composition from multispectral information.
Spectrometer —A types of remote sensing sensors that is designed to detect, measure, and analyze the spectral content of incident electromagnetic radiation.