The SERTEL Radiosonde is a small instrument package that is suspended below a balloon filled with either hydrogen or helium. As the radiosonde is carried aloft it measures pressure, temperature, and relative humidity.
Since the weather we experience is due to dynamic processes that take place throughout the atmosphere, we need to know what is happening throughout the entire atmosphere. These observations are primarily carried out with the aid of radiosondes. These sensors are linked to a battery-powered radio transmitter that sends the information to a ground receiver. By tracking the position of the radiosonde in flight via GPS (Global Positioning System), measurements of wind speed and direction aloft are also obtained.
Technically, radiosonde observations provide only pressure, temperature, and relative humidity data. When the position of a radiosonde is tracked (to obtain wind speed and direction) it can be referred to a rawinsonde observation. Most stations around the world take rawinsonde observations. However meteorologists and other data users frequently refer to a rawinsonde observation as a radiosonde observation.
| TECHNICAL DATA | |||
|---|---|---|---|
| Temperature sensor | Type : Platinum Resistor | Deployment | |
| Measurement range | -90 °C to -60 °C | Ascent mechanism | Balloon -borne |
| Resolution | 0.1 °C | Max shelf life(battery) | 2 yrs |
| Response Time | 0.1 s | Max shelf life(Electronics) | 10 yrs |
| Accuracy | ±1°C | Mechanical Specification | |
| Humidity sensor | Type: Thin – film capacitor | Weight | <180 grams |
| Measurement range | 0 to 100 %RH | Size | 150X90X80(in mm) |
| Resolution | 1 %RH | Unwinder | |
| Accuracy | ±4°C | Material of the string | Non –UV treated polypropylene |
| Pressure | TYPE: Sillicon capacitor | Tenacity | <115 N |
| Measurement Range | 1100 to 1hpa | Length of the string | 55 m |
| Resolution | 0.1 hpa | Unwinding speed | 0.35 m/s |
| Accuracy | ±1 hpa | Weight | 25 g |
| Wind data | Telemetry | ||
| Wind finding options | C/A Code GPS | Transmitter type | Synthesized |
| Wind Speed Accuracy | 0.2m/s | Frequency band | 1668.4 MHz – 1690 MHz (on request) |
| Wind Direction Accuracy | 1 degree | Tuning range | 1668.6 – 1689.8 MHz (on request) |
| Transmitter | Maximum transmitting range | Up to 200 km | |
| Runtime | 120Minutes(with GPS Locking) | Output power (high – power mode ) | 200 mW , typical |
| Wind Finding | GPS | Modulation | GFSK |
| Transmission rate | On full data packet per second | Power Supply | |
| Frequency Range | 400 to 406MHz | Battery | 1 pcs Lithium Thionyl chloride (Li-Socl2) |
| Output Power | 100mW | Battery voltage | 3.7V |
