Monday, June 11, 2018

TDoA with propagation delays based on IRI2016 electron densities

This is a follow-up of this blog post where the method referred to there is applied to TDoA maps. The first example is a STANAG 4285 signal (FUO Toulon) centered on 8436.4 kHz (USB: 8432.6 kHz)

TDoA maps using ground-wave propagation delays


TDoA using propagation delays based on IRI2016


The maps using propagation delays based on IRI2016 electron densities match better the (assumed) true position of the transmitter. It is a small effect but noticeable, and can be seen better in the side-by-side comparison below:

TDoA comparison



Another example are the TDoA maps from the last blog post where the TDoA maps based on more realistic propagation delays are more consistent between the two measurements; both indicate a position on the South coast of Cornwall:

TDoA comparison


TDoA comparison