MoapaPk wrote:The gdb file may actually carry the "accuracy" at the time of the odd excursions. . . .
CrazySanMan wrote:Most notably my elevations are way off. I live at 112' above sea level and there are times when my GPS tells me I'm over 5,000' in my living room.
Day Hiker wrote:MoapaPk wrote:The gdb file may actually carry the "accuracy" at the time of the odd excursions. . . .
Really? Where? How? I have never seen this, and I know intimately the way GDB files are written, since I had to decode them byte-by-byte to write my program that reads and writes GDB files.
kolbi2112 wrote:I have a Garmin eTrex Vista Cx and lately it's been giving me some strange results. Things like 12 mile trips are being logged as 60 mile trips. When I download the track info I see that some of the data points are all over the board, and some point-to-point data says I was traveling at ridiculous speeds (150+ mph) for brief periods of time. Anybody have similar issues or know what the problem might be? My warranty is up so I'm considering buying a new unit if I can't get this fixed.
MoapaPk wrote:Perhaps not the standard gdb, but I have at one time gotten output from MapSource (after directly reading the GPS), and I'd swear it had a column for "accuracy"; but I'm not certain, so that's why I said "may". If that information is never stored in the unit, I guess that I was dreaming. I also seem to remember that the accuracy field was flashing blue and pink, and had giraffes.
MoapaPk wrote:My only experience with gdb on the binary level, was when I used a binary editor to pull out the long and lat from a gdb file that someone had mistakenly tried to edit, then saved as text. My recollection is that the lat and long data were stored as scaled integers. Is there also a field that says how many fields follow in each structure?
MtnHermit wrote:This is likely what you experienced:
This is from a Garmin Colorado. Notice that no errors occurred until deep into the canyon, where the poor signal and multi-path combined to produce the erratic track.
My Venture Cx frequently did this and in addition to earlier comments, I'd add weak batteries as a probable cause.
kolbi2112 wrote:Yes, very similar, although I've seen this problem in wide open spaces as well.
So based on all the replies it sounds like there's a few things I can try on my next outing:
1. Update WAAS settings (if necessary)
2. Change location of GPS (will try to hook it to the top of my pack so it faces up)
3. Hardware/software reset (I've done this once but will try it again)
4. Fresh batteries
I'll be sure to update this thread with the results next week.
Users browsing this forum: No registered users and 0 guests