Feasibility Study of a Multiaperture Telescope for Deep-Space Earth Surveillance

Optical systems launched into space currently have a restriction on their size due to the shuttles payload capacity. The size of optical systems on the shuttle is limited to 3 m in diameter. Multiaperture telescopes can overcome this limitation. Each subaperture of a multiaperture telescope samples the incoming signal. The waves sampled by each subaperture are combined to form a single image. The radiometric model is developed for a geosynchronous orbiting multiaperture telescope used for Earth surveillance. Using the radiometric model, SNR calculations determine if enough signal is present to generate an image. The OTF and PSF are studied to understand the effects of increasing the multiaperture telescopes diameter. Piston and tilt errors are added to the subapertures to provide insight into how these errors can degrade images in a multiaperture telescope. A total of three circular multiaperture telescopes are examined. The results show that 1 m resolution is achieved with a multiaperture telescope consisting of 31 subapertures. Each subaperture is 2.1 m in diameter, and the telescopes overall diameter is 35 m