2.5 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.
SHIPBORNE ENVIRONMENTAL RADAR AND INTERNET DATA HANDLING USING THE
LOCKHEED MARTIN TACTICAL ENVIRONMENTAL PROCESSOR
Timothy Maese Lockheed Martin, Moorestown, NJ 08057., Thomas
McNellis, Jr., James Melody, and Wayne Sabin.