I got a message from the Swiftnav support folks yesterday (I have a piksi multi amongst my little fleet of GPSen) because they had an emergency firmware patch to their kit because of a change in the L2C signal was giving them issues. (Props to them for getting a firmware update out in ~12 hour, too) After a little bit of inquiring, it looks like what happened is that yesterday, the L2 CNAV message started marking all of the L1 signals as unhealthy. If a device actually listens to this health signal (apparently their GPS did), suddenly most GPS satellites become unusable (with the only remaining ones being ones that aren't transmitting an L2C signal). (According to NANU 2014039, you shouldn't be using those health indicators, though it does also say that the L1 health indicators would all indicate "healthy", so this seems to be a departure from their stated plan.) Anyhow, probably doesn't affect anyone here, but I thought it was interesting. Sadly, I can't see what's actually being transmitted, since my only pieces of kit that can decode L2C are my piksi (which won't give me raw NAV/CNAV, and they apparently have zero interest in adding that functionality), and the Novatel OEM628 that I picked up off eBay last year ... which crashes every 20 or 30 minutes if I ask it to decode L2C. Argh. (Maybe u-blox's upcoming kit will be affordable(ish) and have good raw CNAV output... I can hope, right?) -j

Hi The Trimble empire here (NetRS’s and NetR8) seem to be reasonably happy with everything. I haven’t dug into any of the data. They all show L2C tracking along like normal. Bob > On Mar 8, 2018, at 9:23 PM, J. Grizzard <elfchief-timenuts@lupine.org> wrote: > > I got a message from the Swiftnav support folks yesterday (I have a piksi multi amongst my little fleet of GPSen) because they had an emergency firmware patch to their kit because of a change in the L2C signal was giving them issues. (Props to them for getting a firmware update out in ~12 hour, too) > > After a little bit of inquiring, it looks like what happened is that yesterday, the L2 CNAV message started marking all of the L1 signals as unhealthy. If a device actually listens to this health signal (apparently their GPS did), suddenly most GPS satellites become unusable (with the only remaining ones being ones that aren't transmitting an L2C signal). > > (According to NANU 2014039, you shouldn't be using those health indicators, though it does also say that the L1 health indicators would all indicate "healthy", so this seems to be a departure from their stated plan.) > > Anyhow, probably doesn't affect anyone here, but I thought it was interesting. Sadly, I can't see what's actually being transmitted, since my only pieces of kit that can decode L2C are my piksi (which won't give me raw NAV/CNAV, and they apparently have zero interest in adding that functionality), and the Novatel OEM628 that I picked up off eBay last year ... which crashes every 20 or 30 minutes if I ask it to decode L2C. Argh. > > (Maybe u-blox's upcoming kit will be affordable(ish) and have good raw CNAV output... I can hope, right?) > > -j > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.