This calculator plots the wireless sensor signal in relation to the earth's terrain elevation profile (topology)
with ±2 meter (±6.4 ft) accuracy (data from Tessadem) with trees and buildings removed and taking into account
the earth's curvature. Brought to you by BARANI brand
weather stations
INSTRUCTIONS: By entering the radio transmitter and receiver height above ground and GPS
location coordinates, the shape (2D cross-section) of the wireless signal, as represented by the 1st Fresnel
zone, is displayed above the terrain elevation profile between the wireless sensor and gateway receiver antenna.
By varying the wireless sensor radio frequency, the thickness or size of obstruction-free airspace for optimal
wireless signal propagation between the sensor and receiver changes.
Higher frequencies require lower clearances above ground, while their signal strength diminishes faster with
distance.
Lower radio frequencies travel further in the air but require higher clearance between the antenna and the
terrain.
When choosing a location for your MeteoHelix wireless weather station or AWOS weather station, it is important to not
only choose a location without obstructions to optimize measurements per WMO or NWS standards, but a
location with good wireless signal and obstruction free airspace between the sensor and receiver antenna.
Due to the above-mentioned contradictory physical relationships, a compromise must always be made when choosing
the wireless technology and radio frequency along with the sensor and receiver gateway installation locations and heights.
(1 meter = 3.2 ft)
Max Fresnel radius (m) = 60% of Max Fresnel radius (m) = Distance between Gateway and Sensor (km) =
Radio frequencies of common wireless sensor devices in units of Mhz
Bluetooth (2400), LoRaWAN (433, 868, 915), NB-IoT/CAT-M1
(410,700,800,900), LTE(700, 800, 900, 1800, 1900, 2100), GSM/GPRS, 3G, 4G, 5G, Wifi (2400, 5000), ZigBee (868,
921, 2400) or any other wireless radio frequency.
Wireless radio frequency converions: 1 Ghz = 1000 Mhz, 1MHz = 1000 Khz, 1 Khz = 1000 Hz