What is the impact of the topography?
The clear impact is that fewer messages are collected as a result of screening by mountains, cliffs or other obstacles. As a result, you will get more class A & B locations when 2 or 3 messages are collected and poor, or no locations at all with more messages just because they are concentrated on one side of the pass (Doppler curve cannot be assessed). If the platform is moving up and down through different altitudes this will also impact the location accuracy as calculations are done assuming the platform is at a pre-defined fixed altitude.
