The Radio Meteor Project: HROFFT Improves the Second Test

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HROFFT Improves the Second Test

The HROFFT software utilizes an audio input from the radio receiver to the computer sound card and displays the audio signal as a Fast Fourier Transform graphic on the computer screen. In this way, the meteor echo signatures are distinguishable from other types of echoes or interference. Another useful feature of this software is that after a 10-minute interval, the completed, time-stamped transform image automatically saves to the hard drive as a .PNG file. The file size is relatively small and takes little disk space. When the software runs continuously, the files accumulate at 6 images per hour, 144 per day.

The December Geminid meteor shower presented the next opportunity for a system test. In this second instance, the HROFFT software was installed on the XP computer acting as the time server.

The sound card of the computer was then connected to the audio output of the IC PCR1500 receiver. Finally, the antenna was sited in the middle of the parking lot. Initially, the HROFFT displayed long S-shaped forms, which matched known signatures for airplane echoes (the NJAA observatory is in direct line with the flight path of Newark Liberty Airport). This is both good and bad news; first, it proves that the system is able to pick up radio reflections, but the clutter may make meteor detection much more problematic due to the frequency of the planes. Some of the first .PNG files displayed as many as seven planes in a ten-minute span. Fortunately, the air traffic thins out considerably in the early morning hours when meteors are most likely to appear.

HROFFT display, long S-shaped airplane echoes

The NJAA operates on leased premises administered by The State of New Jersey, Department of Environmental Protection, Division of Parks and Forestry