Sensor Network Instrumentation Details
Automated weather stations (AWS):
Andhra Pradesh State Development Planning Society (APSDPS) has installed 1599 automated weather stations (AWS) across the state considering 10km X 10km grid as the basis.AWS measures six weather parameters viz., rainfall, mean sea level pressure, wind speed, wind direction, temperature, humidity and another 3 parameters soil moisture, global radiation and river water level for 959 , 516, and 92 AWS respectively at any given interval of time and transmit the same immediately to central data server at APSDPS.The grid spacing for installation of AWS is designed on a scientific basis and the final one adopted is as per WMO norms.
Soil moisture Sensors:
APSDPS has installed 959 Soil moisture sensors.These sensors are a resistive device that responds to changes in soil moisture. Once planted in the soil, it exchanges water with the surrounding soil thus staying in equilibrium with it. Soil water is an electrical conductor thereby providing a relative indication of the soil moisture status. As the soil dries, water is removed from the sensor and the resistance measurement increases. Conversely, when the soil is rewetted, the resistance lowers. These sensors are unique in taking the resistive measurement within a defined and consistent internal matrix material, rather than using the surrounding soil as the measurement medium. This unique feature allows the sensor to have a stable and consistent calibration that does not need to be established for every installation.
Global radiation sensors:
APSDPS has installed 516 Global radiation sensors. These sensors are used to measure unobstructed daylight which will be useful for field measurement of global solar radiation in agricultural and meteorological studies.
River water level sensors:
APSDPS has installed 92 river water level sensors .These sensors will measure the water levels in the rivers/streams at every one hour interval on real time basis with reference to MSL which stores in the data logger located at remote location transmit the same to the APSDPS server located in AP secretariat.
Reservoir water level recorders:
APSDPS has installed 76 reservoir water level recorders .These recorders will measure the water level in reservoirs of major and medium irrigation projects in AP at every one hour interval on real time basis.
The Automatic Weather Stations even in remote areas work on battery backup and solar panels and transmit data on parameters having following ranges and accuracies.
|1||Rainfall(mm/Hr)||0 to 600mm/Hr||+/- 2.5 %||0.25mm / tip|
|2||Atmospheric temperature(°C)||-30 to 70°C||+/- 0.2°C||0.01°C|
|3||Relative Humidity(%RH)||0% to 100%||+/- 3%||0.1%|
|4||Wind Speed(Kmph)||+ / - 1 Kmph up to 20 kmph
+ / - 2% beyond 20 Kmph
|5||Atmospheric Presure(mbar)||0 to 1100 mbar||+/- 0.15%||0.1 mbar|
|6||Wind Direction(Degree)||0 to 360°||+/- 3°||1°|
|Soil moisture ( %)||0 to 100%||+/- 5%||1%|
|Global radiation (W/m2)||0 to 1750 W/m2||5W/m2|
|River water level (m)||0 to 30m||0-3m -->3mm;
3-30m-->0.1% of the reading
|Reservoir water level (m)||0 to 30m||10mm||10mm|
GSM Technology :
APSDPS installed 2817 AWS & ARGS to measure six weather parameters viz., rainfall, mean sea level pressure, wind speed, wind direction, temperature, & humidity at any given interval of time and transmit the same immediately to central data server at APSDPS.