Satellite images are taken by reconnaissance satellites that orbit the Earth at a relatively low altitude, between 300 to 600 miles (or 480 to 970 km). As the majority of today's satellites are custom made in order to accommodate particular needs of the designer, there is no standard on which photo imagery is based on …
The Ku band (Kurtz-under band) is primarily used for satellite communications, particularly for editing and broadcasting satellite television. This band is split into multiple segments broken down into geographical regions, as the ITU (International Telecommunication Union) determines. The Ku band is a portion of the electromagnetic spectrum in the microwave range of frequencies ranging from …
VSAT (Very Small Aperture Terminal) is basically a two-way satellite ground station with a less than 3 meters tall (most of them are about 0.75 m to 1.2 m tall) dish antenna stationed. The transmission rates of VSATs are usually from very low up to 4 Mbit/s. These VSATs’ primary job is to access the …
An LNB (Low Noise Block aka LNC- Low Noise Converter) is used for communications (broadcast) satellite reception. The LNB is usually affixed either in or on the satellite dish. The LNB’s purpose is to utilize the super heterodyne effect and amplify and convert a wide block (band) of frequencies. This helps compensate the signal loss …
Medium Earth Orbit (MEO) refers to a satellite which orbits the earth at an altitude below 22,300 miles (geostationary orbit) and above the altitude of Low Earth Orbit (LEO) satellites. Medium Earth Orbit represents a series of tradeoffs between geostationary orbit (GEO) and Low Earth Orbit (LEO). Medium Earth Orbit enables a satellite provider to …
Forward Error Correction (FEC) is a type of error correction that involves encoding a message in a redundant way, which allows the receiver to reconstruct lost bits without the need for retransmission. How Forward Error Correction Works FEC works by adding “check bits” to the outgoing data stream. Adding more check bits reduces the amount …
Satellite images were initially the exclusive realm of military and government agencies. They then became commercially available at very steep prices. Technology has now improved to the point where satellite images are available so inexpensively that they are now provided for free online. Free Satellite Images on the Web The best and by far the …