Hi Allen, Spectral scan sum up I and Q for you and give you the magnitude it. Since I and Q are "merged", no phase information is available. As Adrian said, you have to run some math to get power in dBm from the special spectral sample format. If you are able to read Python code, here is an example for the transformation: https://github.com/bcopeland/speccy/blob/master/spectrum_file.py#L57
If you prefer "real code", there is an implementation how to threat the sample data in Adrians Radarlib: https://github.com/erikarn/ath_radar_stuff/tree/master/lib/libradarpkt The paper found on "Atheros CSI Tool" link states: "The CSI measurements are complex values and hence contain two parts, the amplitude and the phase." So I guess that with CSI the I and Q values aren't merged. If you do so, you should be able to calculate the power levels - then you should end up with the same information like from spectral scan. But I do not have any first hand experience with CSI, if you have any, please share :) If you want to play around with the spectral scan feature, I recommend to to give Bob Copelands "Speccy" a try: https://github.com/bcopeland/speccy Hope this helps. Robert 2016-05-09 3:42 GMT+02:00 Allen Welkie <allen.wel...@gmail.com>: > Adrian Chadd <adrian <at> freebsd.org> writes: > > >> >> Well, there's magnitude and phase, and it gives you the values for >> each. You have to run it through math to get a power level for each >> bucket. >> >> https://wiki.freebsd.org/dev/ath_hal%284%29/SpectralScan >> >> You don't get separate readings for I and Q in spectral scan data. >> >> -adrian >> > > I'm confused. You say that the spectral scan only gives the magnitude of the > I and Q values combined, not separate. But then you say that "there's > magnitude and phase, and it gives you the values for each." Doesn't that > mean that you do get both the I and Q values (after converting from > magnitude/phase values)? > > Also, is this the same info that's logged in the "Atheros CSI Tool" > (https://github.com/xieyaxiongfly/Atheros-CSI-Tool)? Or is the spectral scan > data completely different? > > _______________________________________________ > ath9k-devel mailing list > ath9k-devel@lists.ath9k.org > https://lists.ath9k.org/mailman/listinfo/ath9k-devel _______________________________________________ ath9k-devel mailing list ath9k-devel@lists.ath9k.org https://lists.ath9k.org/mailman/listinfo/ath9k-devel
