Testing the first telemetered element

The completed prototype element with a Yagi antenna.
Initial testing was made with one remote element radio telemetered back to the central hub. During the testing phase, various combinations of antenna were tried to improve the immunity to noise. The Yagi antenna, shown here, was subsequently found unnecessary.

The initial installation and tests were done with one three component digitizer and vault instrument on cable and one borehole vault instrument on digital radio telemetry. The vault instrument was compared against a collocated GSETT-II system that had been operational for a number of years and had undergone extensive testing and development.

Comparisons over a period of weeks confirmed that samples from the new system were being timed correctly, that the data was correct, and that the calibration and instrument response was reasonable and stable.

Central communications controller and radio modem used during the prototype tests.
The small size and low power of the central controller allows it to be backed up with a small set of batteries to handle any short term power outages. For use during the tests, the radio and controller were first used outside, then moved next to the workstation inside the lab trailer.

By comparing the performance of the cabled vault element with the telemetered borehole element, the effects of radio telemetry on the data reliability and the performance of the borehole vault during periods of high wind could be determined. During this stage of development, a number of minor changes were made to the software, firmware in the digitizers and communications controller, and hardware to improve performance and to assist in field diagnostics.