Detection and Analysis

Question 1

What are the three ES Mission Areas?

Answer 1

1. Monitor and detect
2. Characterize
3. Geolocate

Question 2

What is Frequency Difference of Arrival (FDOA)?

Answer 2

The difference in frequency, due to the Doppler Effect, of signals travelling from a Primary satellite and an Adjacent satellite

Question 3

What is the Doppler Effect?

Answer 3

Difference in the expansion and compression of a wave, relative to an observer

Question 4

What is Time Difference of Arrival (TDOA)?

Answer 4

Pathlength difference as the signal travels through the Primary and Adjacent satellites

Question 5

What are four requirements needed for Geolocation?

Answer 5

1. Knowledge of signal parameters and frequency
2. Knowledge of ephemeris for all factor satellites
3. Reference emitters with precisely known location
4. Orbital separation requirements

Question 6

What are two limitations of Geolocation?

Answer 6

1. Geo accuracy typically only good for tipping and cueing
2. Inaccuracy in GPS timing can impact results