Pisharoty Sonde system is an indigenous GPS Sonde (Radiosonde) system developed by VSSC/ISRO using commercially off the shelf components (COTS) for high quality atmospheric parameter measurement.

 

The Sonde system consists of the balloon borne segment referred as Pisharoty Sonde and the ground segment referred as Pisharoty Sonde Ground Station. Pisharoty Sonde uses sensors for measuring the atmospheric temperature & relative humidity and GPS receiver module for acquiring the wind parameters, altitude, date and time. Pressure information can be derived from the height and temperature information using software. Sensor and GPS data are processed and transmitted to ground station. Pisharoty Sonde Ground Station consists of the Antenna Assembly & LNB, Receiver and Data Processing & Display unit. Sonde system incorporates the software for solar radiation correction on temperature measurement.

                                                                 Fig. Sonde on ascent                                      Fig.      Sonde  Ground Station

The Sonde system also generates the WMO specified ‘temp’ messages for reporting the data. This indigenous low cost system is compact and light weight (125 grams). Pisharoty Sonde system is validated by comparison ascents with various internationally available Sonde systems and the performance is confirmed. The system performance is evaluated independently by IMD and cleared for meteorological applications. More than 12000 Sondes have been already realized by ISRO.

 

Specifications of Pisharoty Sonde System

A. Sonde

•      Frequency                 : 400 to 406 MHz (user programmable)

•      Power                        : 17 dBm (50 mW)

•      Size                           : 12 cm x 11.5 cm x 9 cm

•      Weight                       : 125 gm

•      Battery                       :  up to 4 hours operation

 

B. Ground Station Receiver

•      Frequency                 : 400 to 406 MHz (user programmable)

•      Sensitivity                 :-117 dBm @ 1x 10-3 BER

•      Connectivity              : Ethernet

•      Power Supply            : 220-230 V AC, 50 Hz

•      Battery Backup         : 6 Hours

 

•      Size                           : 47.5 cm x 23.5 cm x 4.5 cm (19 “ rack mountable)