nanog mailing list archives
Re: NOAA warning for rf communications
From: "Anton L. Kapela" <kapela () mwdt com>
Date: Fri, 24 Oct 2003 12:56:36 -0500 (CDT)
Rodney Joffe said: [snip]
900 mhz and 1800 mhz. And facing East or West. And Satellite, somewhat above 2.0 ghz.
Hmm.
And a significant number of ISPs are currently employing 802.11 2.4 and 5.0+ ghz equipment for last mile links (Proxim Tsunami) and Motorola Canopy gear.
The PSD of the modulation (BPSK) that Canopy employs is rather, shall we say, insane when contrasted with CCK or QAM. I'd be impressed to find a system that experiences errors or goes off-line completely due to a CME. Interestingly, I found a few papers discussing the nature (as well as proposed detection methods, with examples) of the RF signature of a CME. The two most easily understood (imho) would be the following: -http://cdaw.gsfc.nasa.gov/news/cannibalism.pdf "Long-wavelength radio emission in the decameter-hectometric (DH) wavelengths (21280 m or 114 MHz in frequency) has proven to be an important diagnostic for understanding very energetic coronal mass ejections (CMEs) propagating into the outer corona and interplanetary (IP) medium (Kaiser et al. 1998; Gopalswamy et al. 1999; Reiner & Kaiser 1999)." -http://cdaw.gsfc.nasa.gov/publications/gopal2003.cospar.pdf Page three of this paper has an excellent time/spectrum graph of several type II and type III CME (radio) bursts: Again, these researchers are looking at RF spectrum below 10Mhz. One could maybe reason (or argue) that the onset of the type III events (which appear to be initially identified by very broad spectral content) contain components out to (or above) UHF frequency ranges. However, after looking over these two papers, I don't see that there's anything "interesting" above 10mhz, let alone 3 GHz+. If anyone could offer up evidence that has linked path "fading" or "desensitization" (of an operator's equipment) to a type II or III CME, _and_ is operating above 3 GHz, I'm all eyes. --Tk
Current thread:
- Re: NOAA warning for rf communications, (continued)
- Re: NOAA warning for rf communications Robert Mathews (Oct 24)
- Re: NOAA warning for rf communications Bob Snyder (Oct 24)
- Re: NOAA warning for rf communications Kevin Loch (Oct 24)
- Re: NOAA warning for rf communications Chris Yarnell (Oct 23)
- Re: NOAA warning for rf communications Roy (Oct 23)
- Re: NOAA warning for rf communications Todd Vierling (Oct 24)
- Re: NOAA warning for rf communications ed (Oct 24)
- RE: NOAA warning for rf communications Kevin Bednar (Oct 24)
- Re: NOAA warning for rf communications Owen DeLong (Oct 24)
- Re: NOAA warning for rf communications Rodney Joffe (Oct 24)
- Re: NOAA warning for rf communications Anton L. Kapela (Oct 24)
- Re: NOAA warning for rf communications Roy (Oct 23)
- Re: NOAA warning for rf communications Keptin Komrade Dr. BobWrench III esq. (Oct 24)
- Re: NOAA warning for rf communications Marshall Eubanks (Oct 24)
- Re: NOAA warning for rf communications Eric Kuhnke (Oct 24)
- Re: NOAA warning for rf communications Todd Vierling (Oct 24)
- Re: NOAA warning for rf communications Scott Granados (Oct 24)
- Re: NOAA warning for rf communications Owen DeLong (Oct 26)
- Re: NOAA warning for rf communications Scott Granados (Oct 27)