Raytheon is to demonstrate that a ground-based laser can image geostationary satellites under a five-year, $11 million contract from the US Air Force Research Laboratory.
The company will develop a long-range imaging laser-radar (LRIL) transceiver to demonstrate inverse synthetic-aperture ladar (ISAL) imaging of an object in geosynchronous orbit (GEO).
Conventional imaging systems require large apertures (10m or more) to resolve objects in GEO. Synthetic-aperture systems use the relative movement between the object and observer to synthesize a larger aperture, allowing smaller optics to be used.
ISAL illuminates the target with a laser and uses small movements of the object to form high-resolution images using small telescopes with meter-class apertures. The challenge is in actively illuminating an object in GEO and coherently detecting the laser retruns.
The LRIL program has four phases. Phase 1 is producing ISAL imagery in the laboratory at the Maui Space Surveillance System (MSSS) on Hawaii. Phase 2 is low-power imaging of an object in medium earth ordit (or GEO). Phase 3 adds adaptive optics to compensate for atmospheric distortion.
In Phase 4, a high-power laser illuminator will be installed at the MSSS and ISAL images "will be collected from non-optically-augmented geosynchronous objects," the contract announcement says.
Sited atop the 10,000ft Mount Haleakala on Maui, the MSSS is home to the Advanced Electro-Optical System (AEOS), a 3.6m telescope - the biggest in the DoD - that is used to track and image objects in closer orbits for space situational awareness.
AEOS (Photo: US Air Force)