National Aeronautics and Space Administration

Glenn Research Center

Guam (NEN)

The Atmospheric Propagation Monitor in Guam was designed primarily to determine the performance of Ka-band at the tropical location, and to determine the effect to which site diversity may play a role in enhancing overall system availability. The layout of the propagation measurement system consists of two antennas separated by approximately 600 m on a North-South baseline.

Physical layout of the two-element Guam Atmospheric Monitor located at the Guam Remote Ground Terminal (GRGT)

Physical layout of the two-element Guam Atmospheric Monitor located at the Guam Remote Ground Terminal (GRGT)

The two antenna elements are physically situated at the following locations:

North Antenna South Antenna
Elevation: 446 ft. Elevation: 464 ft.
N. Latitude: 13° 35.493′ N. Latitude: 13 deg 35.200′
E. Longitude: 144° 50.420′ E. Longitude: 144 deg 50.455′

The two elements primarily monitor signal attenuation at the two spatially separated locations at the Guam Remote Ground Terminal (GRGT) facility, but they are also capable of recording phase and radiometric brightness temperature. It is believed that the compact rain cell size of the local Guam climate could potentially provide meaningful site diversity gain to improve ground to space link margin availability.

The measurement campaign began in May 2010 and is scheduled to record continuous 1 Hz attenuation and phase data for 5 years.”