How do we categorize observing systems?
Observing systems can be categorized in several ways. Two such ways are 1) fixed versus mobile and 2) in situ versus remote.
Observation systems in meteorology can be thought of as anything that "takes note" of the weather. This could be a totally human system such as a trained severe weather spotter. It could also be a person who daily records the maximum and minimum temperature at his or her location for the state climatological records.
Observing systems are the Weather Service's ASOS system (Automated Surface Observing System), or balloon borne radiosondes that transmit to a ground receiver, values of temperature, relative humidity, pressure and winds as the balloon rises through the atmosphere.
Observing systems are also weather radars, lightning mapping systems and weather satellites.
Virtually anything that makes a systematic note of some aspect of the weather can be called an observing system.
Depending on one's point of view, observing systems can be categorized in several ways. Two such ways are 1) fixed versus mobile and 2) in situ versus remote. In the first, a fixed observation system might be a co-op weather site, an ASOS site, an Oklahoma Climate Survey's Mesonet site, a tower mounted weather radar, or a geosynchronous weather satellite.
On the other hand, a mobile observing system might be a vehicle fitted with weather instruments. It could also be a mobile, truck mounted radar such as the SMARTRs (Shared Mobile Atmospheric Teaching and Research Radar) or the DOWs (Doppler on Wheels).
Another way of categorizing observing systems (and one more from an engineering perspective) is how the observing system makes its measurements. A remote observing system makes its measurements on "remote" objects. For example, a satellite takes pictures of clouds while it is hundreds or thousands of miles away. A radar makes its measurements from the reflections of beam energy off of distant atmospheric material such as cloud particles or sharp discontinuities in the atmosphere.
An observing system alternately may be making its measurements "in situ" meaning roughly "right in the middle" of some phenomenon. An example would be a thermometer, a wind vane or a rain gauge, each of which makes its measurement right where the sensor is located.
One can then have combinations of fixed, mobile, in situ and remote. For example, a typical surface weather site is a fixed, in situ observing system that stays right where it is and needs the weather to come to the site's location in order to measure it. A fixed based radar must also wait until a storm moves within range before meaningful radar data can be obtained.
A mobile, in situ observing system would be a weather instrumented vehicle such as a car, a radiosondes or an airplane. A mobile remote observing system would be a vehicle mounted radar such as the SMARTR or DOW.
NSSL has a long history of projects with observing systems involving all of the above; fixed, mobile, in situ and remote.
- Surface weather sites and projects
- Tall tower system and projects [instrumented,1400' WKY/KTVY transmission tower].
- Sounding systems [WBRT, CLASS, MCLASS, GAUS]
- Instrumented vehicles [Mobile Laboratory, Mobile Mesonet]
- Fixed based Radars: [WSR-57, Norman Doppler, Cimmaron Doppler, NEXRAD]
- Mobile Radars: [DOW, SMARTR]
