Satellite visibility map for emergency services applications

The project CopKa at the Technical University of Munich investigates the possibilities of enhancing the situation awareness during emergency and rescue situations (both routine and major incidents) in a coordination centre, while decreasing the workload of the rescue crew. In the envisioned CopKa scenario, video and telemetry data from different data sources at the emergency scene (vehicle, multi-copter etc.) is streamed to the coordination centre through a secure satellite communication link via a geostationary relay satellite. The satellite link from the emergency site is provided through a deployable high-gain Ka-band antenna, which is mounted on the emergency vehicle. The proposed antenna solution uses a simplified and affordable mechanism that deploys the communication antenna as soon as the vehicle stops and stores the antenna when the vehicle is on the move again (similar to digital satellite news gathering vehicles). The advantage of a controlled satellite link over, for instance, the mobile radio network (MRN) is that it will also work in rural areas where MRN is not provided or not sufficient for high data rates. Furthermore, the MRN might break down during a major event. As a drawback, a satellite link needs an unobstructed sight to the geostationary satellite, which in mountainous regions or urban areas may not be the case. In our study, we address this problem by adding the line of sight information to a street map to show the driver of the emergency vehicle where one or more geostationary satellite links should be available. To calculate the line of sight information, a high-resolution surface model is transformed from a Universal Transverse Mercator projection with quasi geoid height to an earth-centred earth-fixed frame to get a correct geometrical representation. To get a high spatial resolution, the line-of-sight between the centre of a geostationary box and each data point in this model is calculated. To address the restricted resources of a navigation system, only boundary points between visible and non-visible areas are saved for the creation of the map layer.