Reeve Meteor Data

Meteor Trail Reflection Viewer

Anchorage Radio Observatory - Anchorage, Alaska USA
Geographic coordinates: 61.19928 °N : 149.95652 °W

All times are in Coordinated Universal Time (UTC)

The spectrogram on this page is not continuously active. When active, it automatically reloads every 4 minutes but the plots themselves are uploaded at an interval determined by the time scale, typically 12 to 13 minutes. Images are archived and available on request.

Narrowband Spectrum Monitor: One, two or three Icom R-8600 general coverage receivers on a rotable HF log periodic dipole array antenna (KMA18-32). The receivers are set to LSB and tuned to nominal 1 000 kHz above the carrier frequency. The antenna may be pointed 107° or 195° True azimuths toward WWV or WWVH except during HAARP experiments, in which case it may be pointed 60° True azimuth or other directions depending on the experiment. The HAARP experiments usually use different receivers and their audio outputs are not connected to the plots shown here.

The chart shows the relative frequency of the signals over time; usually the the lowest frequency is the bottom trace and the highest frequency is the upper trace. Frequencies monitored usually are WWV and WWVH time services on 5, 10, 15, 20 and 25 MHz (20 and 25 MHz are WWV only) but other frequencies may be used (see below). The vertical scale is in Hz and shows the approximate offset of the received signal from the transmitted carrier frequency. The signal level is under control of the software automatic gain control.

As of 02 April 2021, the trace nearest 995 Hz, if present, is the United States time-frequency stations WWV or WWVH on 15 MHz, the trace nearest 1005 Hz, if present, is WWV on 20 MHz and the trace nearest 1015 Hz, if present, is WWV on 25 MHz.

Signal indications may be due to meteor trail reflections and are shown as ticks or blips or drifting traces usually between 1400 and 1900 UTC. Curly-cue traces are local aircraft reflections usually after local sunrise and before local sunset. Wildly varying traces within a few hours of 1000 UTC (local solar midnight) may be due to aurora radio reflections of the HF carriers. Other traces may show anomalous propagation or even spurious receiver responses. Frequency deviations or frequency disturbances may be due to rapid reconfiguration of Earth's ionosphere caused by sunrise and sunset along the propagation paths or x-ray flux from a solar flare. If the received signals rapidly change frequency by several Hz and then return to normal, they may show a Sudden Frequency Deviation (SFD) caused by an impulsive solar flare. An SFD sometimes is followed by a radio blackout at the lower frequencies.

Meteor Monitor commissioned 7 June, 2014