Satellite+communication

**Satellite Communication**

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Remote sensing is the //**acquisition of information of an object or phenomenon**//, by the use of //**either recording or real-time sensing device(s) that are wireless**//, or not in physical or intimate contact with the object (such as by way of aircraft, spacecraft, satellite, buoy, or ship). In practice, remote sensing is the //**stand-off collection through the use of a variety of devices for gathering information on a given object or area**//.
 * Remote sensing devices **

[|Magnetic Resonance Imaging (MRI),] Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to visualize detailed internal structures. MRI makes use of the property of Nuclear magnetic resonance (NMR) to image nuclei of atoms inside the body. To take an MRI image, the patient lies on a movable bed. The bed enters a strong magnetic field and then certain atoms in the patient's body make special signals. The MRI scanner detects those special signals. The MRI scanner then sends the signal information to the computer, and the computer creates an image of the inner body by using the signal information.

[|Positron Emission Tomography (PET),]

Positron emission tomography (PET) is //**a nuclear medicine imaging technique**// which produces //**a three-dimensional image or picture of functional processes in the body**//. The system detects //**pairs of gamma rays emitted indirectly by a positron-emitting radionuclide**// (tracer), which is introduced into the body on a biologically active molecule. Three-dimensional images of tracer concentration within the body are then //**constructed by computer analysis**//. In modern scanners, //**three dimensional imaging is often accomplished with the aid of a CT X-ray scan**// performed on the patient during the same session, in the same machine.



[|X-radiation (X-RAY)]

Radiography is the use of X-rays to //**view a non uniformly composed material such as the human body**//. By utilizing the physical properties of the ray //**an image can be developed displaying clearly, areas of different density and composition**//. [|Space] Probes

 In modern usage, the term generally refers to the use of imaging sensor technologies including: //**instruments found in aircraft and spacecraft**// as well as those used in electrophysiology, and is distinct from other imaging-related fields such as medical imaging. A probe is a spacecraft that //**travels through space to collect science information**//. Probes do not have astronauts. //**Probes send data back to Earth for scientists to study**//.


 * Satellite imagery **

Satellite imagery consists of photographs of Earth or other planets made by means of artificial satellites. Satellite images have many applications in meteorology, agriculture, geology, forestry, biodiversity conservation, regional planning, education, intelligence and warfare. Images can be in visible colours and in other spectra.

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DISADVANTAGES

Because the total area of the land on Earth is so large and because resolution is relatively high, satellite databases are huge and image processing (creating useful images from the raw data) is time-consuming. Depending on the sensor used, weather conditions can affect image quality: for example, it is difficult to obtain images for areas of frequent cloud cover such as mountain-tops. Commercial satellite companies do not place their imagery into the public domain and do not sell their imagery; instead, one must be licensed to use their imagery. Thus, the ability to legally make derivative products from commercial satellite imagery is minimized. Privacy concerns have been brought up by some who wish not to have their property shown from above


 * Tagging **

Electronic tagging, or ET, is the process of attaching a device to something to track its location and status. The device can come in several forms: bracelet, anklet, dog tag, or microchip. ET is most commonly used in farming to track livestock and other animals. It can also be used to track people, usually by police, for criminals under house arrest. The device's functionality is based around the use of GPS and RFID (radio frequency identification).