8127 USB data?
- Thread starter datainmotion
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Hiya datainmotion,
I do not think this is data, but rather a new radar of some sort. Look at the width, about 20 kHz, is a tad wide for data, not impossibly wide, mind you, just not a common width.
I noticed this signal a couple of weeks ago, would have to check the log for the exact date but I think around 15 June or so. The center freq is about 8135.5 kHz in this case, I have found it on 2 other freqs, around 4175 and up on 12 MHz. Always only one freq at a time, and 8135.5 by far the most common, in fact I have seen it on the other 2 freqs only one time each.
Why do I say a radar instead of data?
The multiple power levels, some burst stronger than others and appearing as multiple stations, could be explained by beam steers. A phased array antenna, as many OTHRs (Over The Horizon Radar) use, can send each burst out in individual directions, it can “steer the beam” between burst transmissions. This causes different power levels at a given receive location for each beam steer.
The width (20 kHz) is unusual for data, but common for radar.
The most telling of all is the waveform itself. I need to put some pictures online to do this explanation justice. The waveform consist of at least two kinds of intelligence each burst, and sometimes as many as 5. While the apparent pseudorandom noise waveform (actually could be some kind of BPSK encoded portion, not sure yet) could be some kind of communications signal the LFMCW embedded in each burst really has no communications application, but it is the most common HF radar waveform found.
I freely admit that I am not sure this is a radar, it could be data. But, I believe it is probably radar.
T!
I do not think this is data, but rather a new radar of some sort. Look at the width, about 20 kHz, is a tad wide for data, not impossibly wide, mind you, just not a common width.
I noticed this signal a couple of weeks ago, would have to check the log for the exact date but I think around 15 June or so. The center freq is about 8135.5 kHz in this case, I have found it on 2 other freqs, around 4175 and up on 12 MHz. Always only one freq at a time, and 8135.5 by far the most common, in fact I have seen it on the other 2 freqs only one time each.
Why do I say a radar instead of data?
The multiple power levels, some burst stronger than others and appearing as multiple stations, could be explained by beam steers. A phased array antenna, as many OTHRs (Over The Horizon Radar) use, can send each burst out in individual directions, it can “steer the beam” between burst transmissions. This causes different power levels at a given receive location for each beam steer.
The width (20 kHz) is unusual for data, but common for radar.
The most telling of all is the waveform itself. I need to put some pictures online to do this explanation justice. The waveform consist of at least two kinds of intelligence each burst, and sometimes as many as 5. While the apparent pseudorandom noise waveform (actually could be some kind of BPSK encoded portion, not sure yet) could be some kind of communications signal the LFMCW embedded in each burst really has no communications application, but it is the most common HF radar waveform found.
I freely admit that I am not sure this is a radar, it could be data. But, I believe it is probably radar.
T!
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