Wind observations at the edge to space, 70–110 km altitude, are challenging. Meteor radars have become a widely used instrument to obtain mean wind profiles above an instrument for these heights. We describe an advanced mathematical concept and present a tomographic analysis using several meteor radars located in Finland, Sweden and Norway, as well as Chile, to derive the three-dimensional flow field. We show an example of a gravity wave decelerating the mean flow.

Little is known about the climate change of wind systems in the mesosphere and lower thermosphere at the edge of space at altitudes from 70–110 km. Meteor radars represent a well-accepted remote sensing technique to measure winds at these altitudes. Here we present a state-of-the-art climatological interhemispheric comparison using continuous and long-lasting observations from worldwide distributed meteor radars from the Arctic to the Antarctic and sophisticated general circulation models.

When a meteor enters the atmosphere, it causes a trail of diffusing plasma that moves with the neutral wind. An interferometric radar system can measure such trails and determine its location. However, there is a chance of determining the wrong position due to noise. We simulate this behaviour and use the simulations to successfully determine the true location of ambiguous events. We also successfully test two simple temporal integration methods for avoiding such erroneous determinations.

The behaviour of position determination with interferometric radar systems and possible ambiguities therein depends on the spatial configuration of the radar-receiving antennas and their individual characteristics. We have simulated the position determination performance of five different radar systems. These simulations showed that ambiguities are dynamic and need to be examined on a case-by-case basis. However, the simulations can be used to analyse and understand previously ambiguous data.