Notes

Outline

Broadband Meteorological Sensors Co-Located with GPS Receivers for Geophysical and Atmospheric Measurements Presented at IEEE PLANS 2002 Symposium By Mustafa  Yilmaz  Paroscientific, Inc.

Outline Introduction GPS-Meteorology Concept Current GPS-MET Networks Current Applications Near Real Time Weather Prediction Flash-Flood Monitoring Long-Term Weather Studies Broadband Resonant Quartz Barometers Expanded GPS-MET Network Applications Infrasound Applications Fog Forecasting Hazardous Materials Detection Airport Applications Conclusions

Weather Is Important Business “One-seventh of our economy, about $1 trillion a year, is weather sensitive.” William M. Daley U.S. Secretary of Commerce

National Weather Service Strategic Plan NWS’s main goal is to become “America’s No-Surprise Weather Service”. The mission is to provide weather, water and climate forecasts and warnings to America to protect life and property and to enhance the national economy. The strategic focus is to provide a seamless suite of weather, water, and climate products and services with time scales ranging from minutes to years. GPS Meteorology plays an important role in achieving the goals in this plan especially for short-term forecasts.

GPS Meteorology Concept The GPS system was deployed by the Department of Defense for improved navigation, positioning, and timing purposes.  There are 24 satellites circling earth twice every day.  Dual-frequency satellites broadcast L1 (~1.6 GHz) and L2 (~1.2 GHz) signals that are received by GPS receivers and converted into position and time information.

GPS Meteorology Concept

GPS Meteorology Why is it important to determine Integrated Precipitable Water Vapor (IPWV)?

Current GPS Networks

Current GPS Networks

Current GPS Networks

Current GPS Networks

Current GPS Networks

Current GPS Meteorology Applications Near Real Time Weather Forecasts Flash Flood Monitoring Long-Term Weather Studies

Flash Flood Monitoring On a yearly average, flooding in the USA kills over 100 people and causes approximately $4.5 billion in damage.

Flash Flood Monitoring While it is raining, if the Integrated Precipitable Water Vapor (IPWV) is still increasing, then more rain will follow.  Scientists are looking for characteristic signatures to determine IPWV and flash flood relationships.

Long Term Weather Studies Knowing the distribution of water vapor in the atmosphere is crucial for understanding climate and climate change.

Long Term Weather Studies

Expanded GPS-MET Network Applications Broadband resonant quartz barometers can pick up signal levels smaller than 1 microbar (0.1 Pa) and can be used for: Infrasound Signal Detection Fog Forecasting Hazardous Materials Detection Airport Applications

Broadband Resonant Quartz Barometers Factors that affect GPS-MET pressure data quality, reliability and integrity: Accuracy Reliability High Resolution

Broadband Resonant Quartz Barometers Repeatability, Hysteresis and Linearity

Broadband Resonant Quartz Barometers Resolution determines the minimum signal a sensor can detect.  With a sensor of inadequate resolution, real signals can be obscured by noise, or sensor noise can be misinterpreted as real signals.

Broadband Resonant Quartz Barometers The result of a noise comparison test performed on broadband resonant quartz barometers showed that the broadband resonant barometers had power spectral density noise levels a factor of 100 lower (20 dB) than the next best transducer.

Broadband Resonant Quartz Barometers When the MET packages are deployed at the GPS receiver sites, careful attention must be paid to the design of the barometer pressure port because wind-induced errors can consume the entire 0.3 hPa pressure accuracy budget.

Infrasound Applications

Infrasound Applications

Fog Forecasting The parameters needed for fog forecasting are  atmospheric humidity, temperature, soil temperature, soil humidity, wind and radiation.  This data is used in a numerical model called COBEL.

Hazardous Materials Detection GPS-MET networks can track the movement of hazardous materials in the atmosphere after a biological attack or a spill.

Airport Applications Wind-Shear and Wake Turbulence create infrasound signals that may be detected with broadband barometers.

Conclusions

Broadband Meteorological Measurement Systems For further information, please check our web site or contact your local company representative and review our paper presented at PLANS 2002 in Palm Spring, California. You can also request information from your GPS receiver manufacturer about Paroscientific’s MET3 and MET3A products.