Shipborne Environmental Radar and Internet Data Handling Using the Lockheed Martin Tactical Environmental Processor

Lockheed Martin, in partnership with the US Navy, has developed an advanced weather radar processor that extracts detailed environmental measurements from existing surveillance radars such as the AN/SPY-1 phased array radar aboard the US Navy's AEGIS cruisers and destroyers. The Tactical Environmental Processor (TEP) program, started in 1996, completed a highly successful at-sea demonstration aboard the USS O'Kane (DDG 77) in the fall of 1999 as the ship transited from Bath, Maine to Pearl Harbor, Hawaii. TEP benefits both the warfighters and the meteorologists, and has been proven to be an effective tool for both communities. Using normally scheduled radar dwells, TEP generates spectral moment measurements (reflectivity, radial velocity, and spectrum width) of the environment surrounding the battlegroup and produces high-resolution weather radar data comparable in quality to that of NEXRAD, the National Weather Service's most advanced Doppler radar. Additional high-sensitivity Pulse Doppler waveforms are available for cloud characterization and wind mapping, and have been shown to provide valuable data on boundary layer turbulence. TEP data are also used by the SPAWAR Refractivity From Clutter (RFC) algorithms, which provide a near real-time assessment of ducting conditions in the surrounding environment by examining the radar clutter return data from TEP.

During the Fall of 1999, Lockheed Martin NE&SS - Moorestown, under sponsorship of the Office of Naval Research, completed several at-sea experiments in which atmospheric conditions were measured by the SPY-1 Phased Array Radar and the Tactical Environmental Processor (TEP) System onboard the AEGIS Destroyer USS O'Kane. The SPY-1 Radar and TEP System were used to collect and process numerous measurements of atmospheric phenomena ranging from heavy precipitation to clear air turbulence. During these at-sea demonstrations, the TEP System was validated by comparing the radar data taken onboard the O'Kane with data provided by NEXRAD sites along the eastern coast of the United States. Additionally, measurements were made on clear air boundary layer turbulence and wind profile maps were generated.

An enhanced version of TEP was deployed onboard the USS Normandy (CG60) for use in the Joint Fleet Exercise 2000 (May 2000) and included several upgrades for information handling and data dissemination off of the Normandy. The most significant upgrade to TEP was the ability to automatically provide rapid spectral moment updates of the surrounding environment and display the weather radar images onboard the Normandy, while transferring the weather radar data to off-ship users such as other warships within the battlegroup. Every 15 minutes, TEP generated a Composite Reflectivity image that was overlaid with a shoreline image and latitude/longitude data and transferred the combined image to the Navy's secure Internet (SIPRNet). The SPAWAR RFC products, including propagation loss charts and ducting assessment charts, were also automatically transferred every 30 minutes through SIPRNet. Outside users, such as MET teams aboard the battlegroup aircraft carrier or forecasters at the fleet meteorology center, could log into the SIPRNet site hosting the TEP data and receive a current weather radar image of the area surrounding the Normandy.

Examples of the NEXRAD-validation of TEP, boundary layer turbulence, and wind profile maps from this experiment will be presented. This paper will also discuss the enhanced functionality of TEP and present some preliminary results of the at-sea demonstrations during the USS O'Kane experiments from the fall of 1999 and the USS Normandy demonstration from the May 2000 Joint Fleet Exercise.