Fog prediction

Frequently Asked Questions

What is a Microwave Radiometer?
A very sensitive passive radio receiver capable of detecting tiny amounts of microwave energy emitted from the atmosphere. By using these measurements with known physics (equations), some meteorological measurements at ground level,  and with years of historical data from radiosondes (weather balloons), the radiometer derives temperature, water vapor, and liquid water profiles.

What are temperature, water vapor, and liquid water profiles?
These are three separate “profiles” — the temperature determined from the ground to approximately 10 kilometers height and similarly for water vapor and liquid water. The measurements are particularly good in the boundary layer.

What is a radiometer used for?
There are many applications of radiometers from augmenting weather balloon soundings (radiosondes) for data to feed into “data hungry” weather models, to fog predictions, to air quality measurements and predictions, to utility load forecasting and wind farm management to a variety of proprietary applications. The photo above shows fog around the San Francisco Golden Gate bridge. Knowing when the fog will form and dissipate is important information for maritime, aviation, and utility companies. (The photo is by -danieli.)

Radiometers are also useful for other non-weather related applications. Examples include: sensing characteristics of snow pack, vegetation, soil moisture, chemical plumes, and many other applications.

What is a Radiosonde?
Also known as weather balloons, the World Meteorological Organization defines a Radiosonde as, “an Instrument intended to be carried by a balloon through the atmosphere, equipped with devices to measure one or several meteorological variables (pressure, temperature, humidity, etc.), and provided with a radio transmitter for sending this information to the observing station.”

Radiosondes are the industry standard measurement technique, so what value does a radiometer add?
A Radiosonde site has an operational cost exceeding $200,000 per year.  A radiometer is significantly cheaper than the annual cost of a radiosonde site, and radiometers give radiosonde-equivalent accuracy every few minutes, rather than once or twice per day. Radiometers are not subject to being blown off-course by wind, so the observation is more uniform from day-to-day.

Why would I want radiometer information when the radio, television and internet tell me what the cloud cover (called the planetary boundary layer by meteorologists), will be for the next 3 days.
Current weather predictions are made by meteorologists using sophisticated software models that ingest the twice-per-day radiosonde data. Having radiosonde-equivalent data, as from a radiometer, reduces the demands on these models to extrapolate (that is, predict) up to 12 hours in the future. Therefore, the predictions would be improved. In the sate of Colorado, the state radiosondes are not released during the times of day having the most dynamic behavior, the early afternoons when thunderstorms are forming. Continuous measurements of a radiometer reduce prediction errors by providing much fresher data.

What distinguishes radiometers from Radiometrics?
Radiometrics makes small, lightweight radiometers that can be installed and maintained by one person. They are easy to ship and transport. The radiometers from Radiometrics have state-of-the-art software visualization tools.

With the Earth Networks announcement, what are you doing to support large data information networks?
Radiometrics is executing their 2010 plan to seamlessly interface with a large network in the United States, made possible with an established network developed by Earth Networks. This includes providing end-users with more and more tools.

What engineering efforts are being applied to improve your products?
Our expert R&D team is continuously improving and inventing new software products and features for both hardware and software. Although we keep the new development confidential, you can rest assured our products will continue to improve, as they already have for more than 20 years.

What is your warranty policy?
Radiometrics offers one or two year warranties. Extended warranties are also available.


More detailed questions can be answered by contacting us.