Originally posted by

**fungus**View Post**AFFECT OF HEIGHT OF ADS-B RECEIVING ANTENNA ON THE RANGE:**

Height of ADS-B Receiving Antenna does NOT appreciably affect the Range.

In case of

**Ground-to-Ground Communications**at UHF/Microwave, the heights of both the receiving and transmitting antennas greatly affect the range.

In case of

**Air-to-Ground ADS-B Communications**, the Transmitting antenna is on the Aeroplane, which is several thousand feet high. The contribution of height of receiving antenna to the overall range is therefore not appreciable.

The range is combination of ranges of transmitting & Receiving antennas. Overall Range = Range of Transmitting Antenna + Range of Receiving Antenna = 1.41 x √h1 + 1.41 x √h2 miles, where h1 = height of transmitting antenna in feet. h2 = height of receiving antenna in feet.

Based on these formula, I have calculated the Range for various heights of Receiving Antenna and Airplane, and have tabulated the results. These results show that increasing height of RECEIVING Antenna from 25 to 200 feet does not appreciably affect the overall range of ADS-B.

PLEASE SEE ATTACHED PICTURE BELOW for the tabulated results:

uploadfromtaptalk1389140108373.jpg

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