Navy Satellite- Comms. Flashcards
What are 3 segments in Comms satellite system?
- ground
- space
- control
What is a comms satellite?
a specialized wireless receiver/transmitter that is launched in orbit around the Earth
What is a ground segment?
equipment on shore and ships used to transmit and receive message sent through SATCOM circuits
What is a space segment?
includes the actual satellite and its associated equipment in space.
What is control segment?
includes all administrative operations to manage satellites and ensure they are operational.
Also manages SAR and SAAs.
What are 2 satellite modes of operations?
active and passive
What is passive Operations?
reflects radio waves transmitted from one ground terminal to another without amplification. does not alter the signal
What is active?
changes received signal before transmitting signal back to the Earth
What are the orbits?
Synchronous and Asynchronous
What is a Asynchronous orbit?
satellite travels faster or slower than the speed at which the Earth rotates
What is Synchronous orbit?
satellite travels at the same speed that the Earth rotates
What are the types of orbits?
LEO, MEO, GEO, Molniya/HEO.
What is LEO?
Low Earth Orbit that is 400-1600 miles above Earth
What is MEO?
Medium Earth Orbit 1500-6500 miles above Earth
What is GEO?
Geosynchronous 22500 miles above the Earth
What is Molniya/HEO?
Highly Elliptical Orbit 24000 miles apogee and 900 mile perigee. is a asynchronous orbit.
What are the type of SATCOM frequencies?
UHF, SHF, EHF.
What is the characteristics of UHF?
300 MHz to 3 GHz, low capacity, high mobility, low anti-jam capability, vulnerable to nuclear radiation, widely use in the Navy on all types of ships, some aircraft and shore facilities
What is the characteristics of SHF?
3 to 30Hz, high capacity, low mobility, moderate anti-jam capability, found in aircraft carriers, large amphibious ships, and on some cruisers, destroyers and shore stations
What are some characteristics of SATCOM EHF?
30 to 300 GHz, high capacity, moderate mobility, high anti-jam capability, nuclear survivable, subject to wether conditions
