Networked optical constellations for prompt earth imagery acquisition and crisis management: a tradeoff analysis

This paper presents a systems architecture methodology that has been developed to analyse architectures for Low Earth Orbit (LEO) Earth Observation systems. Timeliness and service availability are fundamental aspects when dealing with earth observation missions, which are often required to perform critical tasks in a prompt manner. For example, in the event a natural disaster occurs, the time needed for the acquisition of the first image of the area of interest is subject to a series of delays that might seriously affect the effectiveness of the effort to provide support to emergency management operators. The overall delay, commonly named response time, from the initial request of image acquisition to its final delivery to the intended recipient is composed of a number of different subdelays: a first delay for the reception of the appropriate telecommand by the satellite that has been identified as the most suitable for the purpose; a second delay for the time needed for the satellite’s next useful pass over the disaster area; a third delay consisting in the time elapsing before it reaches an available ground station for the final transmission of the image to the crisis management center. Moreover this process could need to be iterated multiple times, multiplying consequently this series of delays. Although not all these delays can be completely eliminated, some of them can be consistently reduced -when dealing with the architecting of new space infrastructures for the observation of the Earth- with appropriate technical solutions. This paper addresses the definition of figures of merit relevant to this feasibility assessment, and conducts a systems architecture analysis with an integrated approach capable of eliciting and assessing technical tradeoffs between delivered performance benefits and added complexity associated with EO imaging solutions, and identifying efficient architectures of LEO infrastructure for more detailed design studies.