Solar power system. Electrical power is supplied by a battery bank and array of solar panels. The 225 GHz tipping radiometer is the benchmark instrument for site characterization. It measures the atmospheric absorption every 10 minutes and atmospheric emission stability every fifth hour. Operation is automatic.
Sporadic repair is required.
The data are retrieved daily by telephone and summaries are posted monthly. The data are made available to interested parties in machine readable form. The site test interferometers directly measure the tropospheric phase stability. They observe unmodulated 11.5 GHz beacons broadcast from geostationary satellites and measure the phase difference between the signals received by two 1.8 m diameter antennas 300 m apart. Because the atmosphere is non-dispersive away from line centers, the results can be scaled to millimeter and submillimeter wavelengths.