This month Raytheon begins integrated tests on its APY-10 inverse synthetic aperture radar for the Boeing P-8 Poseidon maritime patroller. The company will supply three more radars by year-end under the terms of the system design and development contract. It will test the sensor from a tower, before the first unit gets fitted to a P-8 for a first flight in 2010. The first P-8 (T-1) will fly without radar, so T-2 will take the first APY-10 aloft.

Faced with the many challenges of converting a civil airliner (737-800) into a military maritime patroller, the U.S. Navy chose a low-cost, low-risk approach to providing the initial radar. At the same time, the service says it is happy with the performance of the APS-137 currently flying in P-3 Orions. Consequently, the APY-10 is based closely on the P-3 radar and retains a mech-scan antenna.

There are some key differences, however. Firstly, the Navy demanded a color weather radar function, which has been incorporated, while Raytheon has undertaken numerous changes to improve already impressive reliability figures. The overall system has shrunk due to advances in technology since the APS-137 was developed. The APY-10’s slightly smaller antenna fits the confines of the P-8’s radome, with negligible performance effects.

While performance and functionality are essentially the same as those of the Orion’s radar, the APY-10 interfaces with the Poseidon’s mission computing data system, so that it can run from any of the five operator stations. In the P-3, the APS-137 could operate from only a single dedicated workstation.

Of course, Raytheon has a wide portfolio of more advanced electronically scanned radars, and could have offered a more advanced system for the P-8 if the Navy had required it. Future P-8 development will follow a series of spiral technology insertions, and a more advanced radar might be a part of that process.