US tactical cruise missiles are getting smarter as the result of two initiatives by the US Air Force and US Navy.

Boeing has delivered six Block 1A Conventional Air-Launched Cruise Missiles (CALCM) to the USAF for inspections and ground checks prior to a planned first flight in February.

The improvements to CALCM include a third-generation GPS satellite navigation receiver, advanced navigation software and a GPS anti-jam system. This year, Boeing will deliver more than 200 of the hardware/software enhancement kits to be retrofitted into earlier Block 0 and Block 1 models.

The company is converting 322 surplus air-launched cruise missiles into CALCMs. Of those, 132 will incorporate the Block 1A improvements. Boeing has already delivered 140 of those 322 units in the Block 1 configuration. The final 50 missiles, designated AGM-86D, will also include a new Advanced Unitary Penetrator developed by Lockheed Martin.

The USN, meanwhile, plans to upgrade the Raytheon Tactical Tomahawk missile with a Precision Terrain Aided Navigator (PTAN). Contracts will be awarded for a feasibility demonstration and risk reduction effort involving PTAN elevation sensor and navigation update processing technology. Preliminary design of a PTAN, suitable for incorporation into the missiles, and the engineering and manufacturing development programme are also included.

The effort is expected to result in an engineering change proposal and production cut-in of PTAN into the next-generation Block IV Tomahawk missile, to be fielded in fiscal year 2003.

The preplanned product improvement would initially augment the current GPS, Inertial Navigation System and Digital Scene Matching Area Correlator (DSMAC) guidance systems featured in Tomahawk.

PTAN would provide all-weather, GPS-independent en route and terminal navigation updates, using a sensor measuring terrain elevation and correlate those measurements to digital elevation maps loaded into the weapon. PTAN will initially complement GPS and DSMAC while replacing the existing radar altimeter.

PTAN is expected to eventually replace the DSMAC and GPS, providing Tactical Tomahawk with totally autonomous navigation capability.

Source: Flight International