Simulation showing the expected uncertainties when performing multilateration on a STEREO and Wind system. The solid line represents the average 1σ uncertainty of the sources in the simulated burst, and the dashed line represents the maximum and minimum 1σ uncertainties of the positions of the simulated bursts. The angle of separation of the Ahead and Behind spacecraft of the STEREO system with respect to Wind shows a strong contribution on the uncertainty of the localisation method when two or more spacecraft are close to each other. This simulation was performed assuming different cadences, which also had an effect on the performance of the multilateration, but it was not as dominant as the angle of separation. These simulations suggest that BELLA will have a minimal contribution to the uncertainty of the results if the angle of separation is in the range of ±[45° ,165° ]. This range is defined as the ‘sweet spot’ region and is highlighted in green. See Fig. 3 for frames of this simulation.