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Weather Sensors > MIAWSMedium Intensity Airport Weather System (MIAWS) Coverage Analysis
This series of analyses estimates the likely performance achievable by providing MIAWS Program candidate airports with information from nearby weather sensors. The analysis of each candidate airport includes:
The current analysis evaluates nearby Next Generation Weather Radar (NEXRAD) Systems. Follow-on efforts will evaluate the coverage of Low-Level Windshear Alert System - Replacement System (LLWAS-RS) and Airport Surveillance Radar Version 11 (ASR-11) as those systems are incorporated into the MIAWS sensor suite.
The MIAWS program was established to develop a weather processing and display system for medium-level operations airports that lack dedicated weather sensors. Its goal is to provide near-term, low-cost weather information to these airports. Airports of this size have too few operations to justify the cost of a dedicated weather system such as the Terminal Doppler Weather Radar (TDWR), ASR-9 Weather System Processor (WSP), or Integrated Terminal Weather System (ITWS), but could benefit from the higher level of safety that a MIAWS system would provide. MIAWS seeks to provide weather coverage to these airports by using existing, nearby sensors.
MIAWS Coverage Analysis Methodology
The MIAWS coverage volume analysis measures the ability of the NEXRAD system to provide coverage to the TRACON/6-Level Precipitation Product Volume. This precipitation product displays the location and intensity of weather in the TRACON’s 60-nmi radius. Intensity is defined as one of six National Weather Service (NWS) levels.
The TRACON/6-level precipitation detection coverage of NEXRADs near the airport are overlaid on the surrounding terrain, providing a plan view.
TRACON/6-Level Precipitation Product VolumeThe volume is a cylinder with a 60-nmi radius, representing the coverage range of an ASR-7, -8, or -9 radar system located at the MIAWS site Airport Reference Point. The height of cylinder is 10,000 to 30,000 feet, which is the average altitude range of the high-intensity core of a developing storm.
The Plan View
The plan view of the airport and nearby NEXRADs is generated using TSC's Detection Coverage Analysis Tool. It shows the 60-nmi radius of the TRACON airspace in red. The light blue circles show the range extent of the center of the lowest beam angle of each NEXRAD system as it intersects the 10,000-ft minimum altitude of the TRACON coverage volume. This occurs at approximately 90 nmi laterally for an unobstructed beam.
Terrain/Line Of Sight AnalysisTerrain or LOS analysis examines the effects of ground obstructions on the lowest elevation scan beam of the NEXRAD system. The terrain around each candidate NEXRAD system and around the MIAWS airport is modeled using digital elevation maps. LOS plots are generated by modeling the propagation characteristics of the lowest elevation scan beam for each NEXRAD system over the digitized terrain.
Weather Detection Performance Analysis
MIAWS weather detection performance analysis models the NEXRAD detection of different storm types. Storm profiles and NEXRAD detection estimates are modeled using the Radar Characterization Model, an analysis tool developed by Technology Service Corporation. This tool generates three products for each set of storm parameters:
weather reflectivity truth model for a defined storm
indicated reflectivity model as an estimate of the sensor’s detection performance
reflectivity measurement errorThe reflectivity measurement error indicates the reflectivity difference between the modeled storm and the storm as detected by the NEXRAD.
