Modulation Representing digital signals as analog waveforms Baseband signals Signals whose frequency components are concentrated around zero Passband signals Signals whose frequency components are centered at some frequency fc away from zero Baseband signals can be converted to passband signals through modulation Multiplication by a sinusoid with frequency fc Eytan Modiano
Used for analyzing network performance In packet networks, events are random Random packet arrivals Random packet lengths While at the physical layer we were concerned with bit-error-rate, at the network layer we care about delays How long does a packet spend waiting in buffers?
Routing Must choose routes for various origin destination pairs o/d pairs) or for various sessions Datagram routing: route chosen on a packet by packet basis Using datagram routing is an easy way to split paths Virtual circuit routing: route chosen a session by session basis Static routing: route chosen in a prearranged way based on O/D pairs Eytan Modiano
Electromagnetic Formation Flight NRO DI Final review Friday, August 29, 2003 National reconnaissance office Headquarters Chantilly, VA LOCKHEED MART Massachusetts Institute of Lockheed Martin Corporation
ADCS Motivation Motivation Sensors GPS star trackers. limb In order to point and slew optical sensors rate gy ros. inertial systems, spacecraft attitude control measurement units provides coarse pointing while
Earth Orbiting Clusters Edmund M C Kong SSL Graduate Research Assistant Prof david w. miller Director, MIT Space Systems Lab Space 2001 Conference& Exposition Albuquerque August28-30,2001
