The Hazardous Weather Detection and Display Capability (HWDDC) system provides real-time environmental sensing onboard US Navy ships. HWDDC provides ‘through-the-sensor' (TTS) weather radar information from the tactical radar returns from the US Navy's SPS-48E 3-dimensional air surveillance radar. The system consists of a passive data tap within the SPS-48E radar signal processor and an adjunct data processing computer that automatically processes the SPS-48E returns and generates weather radar data files and images. The first SPS-48E HWDDC system was recently installed on USS PELELIU (LHA-5) as a temporary installation for demonstration at sea during the PELELIU's deployment starting on 14 February 2006. The first weather the ship encountered was light showers that appeared on the radar during training exercises northeast of Hawaii. The first real-world test of the HWDDC came in the early morning hours of 22 February 2006 when heavy weather moved in on the ship from the northwest accompanied by thunder and lightning. Using the weather radar display on the bridge and interpretation provided by onboard meteorology (METOC) personnel, the Commanding Officer of the PELELIU maneuvered the ship to avoid the hazardous weather and was able to conduct a morning of flight operations that he would have otherwise lost.

Three major conclusions have been drawn from the HWDDC experiments and demonstrations, along with previous Navy experiments with the SPY-1 radar, conducted to date. First, weather detection capability can economically be added to tactical radars and provide simultaneous aircraft and weather surveillance. Second, tactical air-defense and surveillance radars can provide quality weather data to support tactical operations. Third, TTS capable platforms provide real-time, relevant weather information in the operational areas rather than relying on forecasts based on remotely obtained data.

The HWDDC system is based on commercial off-the-shelf PC technology for the real-time radar processing and provides a web-service based operating interface and display for viewing radar imagery. Real-time radar imagery are provided via the ship's local area network (LAN) to various users onboard the ship, such as the meteorology and oceanography department, aircraft pilot ready rooms, primary flight operations, and the bridge. The production system configuration will allow not only users onboard the ship to view data, but will also provide off-ship user access to the radar data over the Navy's secure network, providing data and imagery to forecasters and warfighters in a real-time manner.

The HWDDC processor performs several of the functions of a traditional weather radar processor, such as spectral moment estimation, but also contains specialized processing to extract accurate data from the tactical radar scan that is unlike traditional weather radars. The processor contains significant volume recombination processing to gather data from the rapid radar scans into a coherent data volume, and current upgrades to the system will also provide sea-surface clutter filtering, point target removal, and advances geo-political mapping and storm tracking.