Tomographic ISAR imaging of satellites: A ground-based experimental validation

As the number of parties with access to Earth’s orbit increases, more low-cost satellites with only limited onboard diagnostic tools are brought into orbit. As a service to satellite operators an external imaging of satellites in space would give valuable information. Additionally, a tight observation of satellites is of international interest. An experimental radar system called IoSiS (Imaging of Satellites in Space) was developed at the German Aerospace Center (DLR) and is capable of delivering high resolution 2-dimensional radar images. For a more thorough observation and an easier interpretation of the collected images, the IoSiS project is moving towards complete and true 3-dimensional imaging through the use of distributed receivers. Here, theoretical analysis is shown to gain first insights into synthetic aperture radar (SAR) tomography in this new context. A new ground-based system for demonstration purposes is developed from the ground up, and is able to perform tomographic imaging. The newly developed system is FPGA based, and implements a new state-of-the-art system-on-a-chip. Interpretation of the gathered 3-dimensional measurements and multiple visualization approaches are shown and tested.