The on-orbit demonstration of the small SAR satellite. Initial calibration and observations

The demand for Synthetic Aperture Radar (SAR) spaceborne data is on a rise. Cloud cover and sunshine duration are major factors that limit the usability of optical sensors e.g. an annual sunshine in Tokyo, Japan amounts to just 1881 hours, which is approximately 21% of the year. This prohibits reliable satellite monitoring. Our mission is to provide dependable Earth data regardless of weather and time of the day by the construction of the SAR satellite constellation. These small-size satellites are designed to achieve sub-daily revist, while keeping the overall mission cost low. We expect that the insights provided by frequent Earth monitoring will improve private-, business-, and government decision making resulting in more resilient economies and supporting sustainable development. We have launched our first demonstration satellite - StriX-a - in December 2020 and are preparing to launch a second satellite - StriX-ß - in early 2022. Our ultimate goal is to build a constellation - StriX - consisting of 30 satellites. The name StriX was inspired by the genus of owls, which are known for their ability to see in the dark. In this paper, we will discuss a demonstration satellite's specifications and follow with the on-orbit calibration based on Amazon rainforest observations. Finally, example observations of oil spills off the coast of Syria will be presented.