Question

How many surfaces are required to geolocate a transmitter on a two-dimensional plane using time difference of arrival approach?

(a) Two

(b) Three

(c) Four

(d) Five

This question was addressed to me in an internship interview.

This interesting question is from Next Generation Wireless Network topic in section Next Generation Wireless Network of Cognitive Radio

Answer 1

Right answer is (b) Three

The explanation is: When a number of receivers at known locations receive the same sign, the obtained hyperboloids intersect at the location of the transmitter. The number of surfaces required to geolocate a transmitter in 2 D plane is three and the number of surfaces required to geolocate a transmitter in 3 D plane is four.