Types of orbits

 • What is companding ? Companding  refers to a technique for compressing and then expanding (or decompressing) an analog or  digital  signal. It is a combination of the words "compressing" and "expanding." • Types of companding : There are two types of companding * A law Companding *  μ-law companding • Why is companding needed ? Companding is a common technique for reducing the data rate of Audio signals by making the quantization level unequal.  • Applications : *  Companding is used in digital telephony systems, compressing before input to an Analog to digital converter , and then expanding after a digital to analog converter. *  This method is also used in digital file formats for better signal-to-noise ratio  (SNR) at lower bit rates. *  Companders are used in concert audio systems and in some  noise reduction schemes .

  There are several types of Earth orbits, and each offers certain advantages and capabilities. •Low Earth Orbit (LEO) •Medium Earth Orbit(MEO) •Geosynchronous Orbit (GSO) & Geostationary Orbit (GEO) • Low Earth Orbit (LEO) LEO is commonly used for communication and remote sensing satellite systems, as well as the International Space Station (ISS) and Hubble Space Telescope. •Medium Earth Orbit(MEO) MEO is commonly used for navigation systems, including the U.S. Global Positioning System (GPS). A depiction of LEO and MEO. Credit: The Space Foundation • Geosynchronous Orbit (GSO) & Geostationary Orbit (GEO) Objects in GSO have an orbital speed that matches the Earth’s rotation, yielding a consistent position over a single longitude. GEO is a kind of GSO. It matches the planet’s rotation, but GEO objects only orbit Earth’s equator, and from the ground perspective, they appear in a fixed position in the sky. GSO and GEO are used for telecommunications and Earth observation. A ...