Aerological Observation (GPS sonde Sounding)

Aerological observation

The Aerological Observation Division launches GPS sondes (instruments for collecting meteorological data) suspended from balloons and observes profiles of pressure, temperature, humidity and wind twice a day.

There are around 800 upper-air sounding sites worldwide. At each one, GPS sondes are launched simultaneously at 00 and 12 UTC (09 JST and 21 JST). In Japan, extra GPS sondes are occasionally launched for observation of tropical cyclones, experiments and other work.

GPS sonde launch

GPS sonde

GPS sonde consists of a temperature sensor, a humidity sensor, a GPS antenna, processors and electric circuits.

GPS sonde specifications

Metric	Measurement method(iMS-100)	Measurement method(RS41-SG)
Temperature	Thermistor	Platinum Resistor
Humidity	Electrostatic capacity type	Thin-film capacitor
Wind direction	GPS wind finding	GPS wind finding
Wind speed	GPS wind finding	GPS wind finding
Altitude	Calculated from GPS	Calculated from GPS
Pressure	Calculated from GPS	Calculated from GPS

Examples

Example profiles are shown below. The vertical axis represents altitude or pressure, and the horizontal axis represents a metric (temperature, humidity, wind direction or wind speed). These figures depict upper-atmospheric conditions.

Upper-air profiles. Left: temperature (red) and humidity (blue). Right: wind direction (green) and wind speed (blue).