Solution

The solution was divided up into three steps:

Step 1 was to calculate the latitude of the EPIRB signal. This was calculated by determining the time at which the maximum amplitude of the derivative of the received frequencies occurred. The longitude was calculated based on the speed of the SARSAT satellite and the time the maximum occurred.

Step 2 was to generate a series of known received frequency patterns at the calculated longitude. The derivative of each of these was taken. Finally, the maximum of each derivative was determined and plotted against distance. From this we could determine amplitude per unit distance.

Step 3 was to place the actual derivative of the received frequencies into the set of known derivatives. From this we could interpolate the appropriate amplitude per unit distance factor to use. This factor could then be multiplied with the maximum amplitude of the received derivative to determine the distance from the SARSAT satellite to the EPIRB. Using this distance and the orbit of the SARSAT satellite, two solutions will be generated, one to the west of the satellite and one to the east. Flight plan information must be utilized to determine which solution is correct.