Hi Nigel, AMU and SNR are two different scales. I do not have a translation. A Kepler award recepient once explained Trimbles AMU as "a meaningless unit". That said, SNR or C/N0 values cannot be directly compared between different receivers since the measures might be taken at different points in the receiver.
The Trimble monitor program can be made to switch between AMU and SNR in one of the configuration menues. I think you might have switched to SNR. With above uncertanty of specific SNR definitions noted, most receivers are enjoying an excellent signal if the highest elevation receivers have a SNR above 50. If the highest SVs get +45dB that is still decent. -- Björn > > In a message dated 22/11/2009 19:45:35 GMT Standard Time, [email protected] > writes: > > changing the AMU thresholds to 2.0 as suggested by Warren fixed the > problem, the unit is now working properly, thanks much for the hint. And > no, this > was not obvious to me. > > > Hi Said > > Just out of interest, what levels of AMU are you seeing reported? > > According to Trimble's Thunderbolt Monitor version 2.6 the six satellites > I'm tracking right now are showing AMU values of over 40 and another stops > tracking when its AMU drops to approx 33 but starts tracking again at a > reported AMU of approx 36 to 37. > > My signal level mask is set to 4.0, and I don't seem to have had any > problems because of that, but I'm intrigued as to the actual relationship > between the quantity described as the signal level mask and the reported > AMU > levels. > I would have assumed the units to be the same but that doesn't seem to be > the case. > > OK, so I've just dropped the threshold to 2.0 and am now tracking eight > satellites, with the reported levels for the one mentioned above still > varying > as before and another just below 30 with neither dropping out, but I'm > still non the wiser as to the actual value of the set threshold in terms > of > the reported AMU levels. > > regards > > Nigel > GM8PZR > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
