Semi-Automated Weather Observing System PC display (SAMOS)
All Met sensors feed information directly in to the system and updates every minute. Cloud base information derived from a LCBR (Laser Cloud Base Recorder),visibility from a Visiometer and air temperature/dew-point from a combined ERT (Electrical Resistance Thermometer) and Humidity sensor housed in a Stevenson Screen in a Met enclosure. Correction factors are built in to derive local QNH and QFE values. QFF(although not generally used in aviation) is very similar to QNH in value. The only difference being that QFF is the mean sea level pressure (MSLP) according to ambient air temperature (+9c in this example). QNH is MSLP according to the International Standard Atmosphere(ISA) whereby the air temperature is assumed to be 15c! Isobars on weather maps are drawn up against values of QFF. Rainfall (intensity/rate and amount) can also be derived from sensors and displayed on the PC.
Semi-Automated Weather Observing System PC display (SAMOS)
All Met sensors feed information directly in to the system and updates every minute. Cloud base information derived from a LCBR (Laser Cloud Base Recorder),visibility from a Visiometer and air temperature/dew-point from a combined ERT (Electrical Resistance Thermometer) and Humidity sensor housed in a Stevenson Screen in a Met enclosure. Correction factors are built in to derive local QNH and QFE values. QFF(although not generally used in aviation) is very similar to QNH in value. The only difference being that QFF is the mean sea level pressure (MSLP) according to ambient air temperature (+9c in this example). QNH is MSLP according to the International Standard Atmosphere(ISA) whereby the air temperature is assumed to be 15c! Isobars on weather maps are drawn up against values of QFF. Rainfall (intensity/rate and amount) can also be derived from sensors and displayed on the PC.