Q 1.13 (b) How are the considerations for military us of satellite communication mentioned above effected in practice?
Communication security is obtained through highly secure encryption techniques at originating points. The strength of chosen encryption depends on the type of data in question – sensitive, classified, secret, top secret, etc.
Transmission security is improved through a variety of countermeasures that include jam resistant, adaptable signal waveforms, e.g., spread spectrum and frequency hopping.
Countermeasures that lower probability of detection and interception utilise advanced signal processing techniques. For instance, uplink adaptive beam forming minimizes the probability of detection and very narrow transmission beam-width reduces the probability of interception.
Military satellites are susceptible to physical or electromagnetic attacks like nuclear burst, lasers, particle beams and others. Survivability is improved through hardened components; clever use of orbital parameters to reduce the susceptibility of satellites to physical damage; survivable satellite constellation design that provide redundant transmission paths and in-space connectivity.
The user terminals are required to operate in very hostile conditions and environments. Therefore they are ruggedized. Implementation ranges from hand-held terminals to those installed on rapidly moving platforms like war fighters.
Selection of orbit depends on the desired coverage and orbital robustness. Therefore geostationary, low, medium and highly elliptical orbits or combinations thereof can be used.