accuracy problems...

[sudamar]

I have been using my Garmin 60csx since spring and have had no problems....but the last three caches I have gone after were found about 60'-75' from where my GPSR said they should have been. At first I thought the coords of the cache was wrong, but now I'm beginning to think it is my GPSR. What could suddenly cause it to be off that much. Any suggestions would be appreciated. Thanks.

[+EraSeek]

Possibly you have your map datum set to something other than WGS84. Possibly you ran into multipathing each time (trees, buildings, bouncing signal).

[+ventura_kids]

There have been issues with the 60 series receivers where they just get goofy readings. We cached with a group of 5 receivers, and one of them was always 40 feet off. They ended up sending it in and getting a new one under warrantee.

I'd try pulling the battery and let it go dead for a couple of minutes.

I'd also load the most recent firmware (from Garmin site).

If that doesn't seem to fix it, try caching with someone else who has one. See if they both read the same.

Good luck.

[+Sputnik 57]

As EraSeeker said, most GPSr's with a consistent error of this magnatude have the datum set to something other than WGS84. If you accidently set it to NAD27, set it back and you should be good to go. Rarely (I'm guessing 1 in 100?) have a hardware problem. If you happen to be one of the unlucky few, Garmin's tech support and warranty work is second to none.

[+ventura_kids]

Try changing batteries! That has helped some people too.

yes, really!

[+GeekBoy.from.Illinois]

I did some testing with a Magellan eXplorist 600 and a Garmin GPSMap 60CSx recently while working a puzzle cache in my area. You need to take 4 readings at specific locations and compute the intersection point of the lines created by the 4 readings, then offset from there to the final cache location. Since the offset is the same for all GPSr's tested, those are not relevant to this testing. In this test, I tested two different Magellan units (both eXplorist 600's) and a Garmin unit. The end result had one of the Magellan's and the Garmin only differing by 2 meters (east) for the intersection point (with 4 meter accuracy readings at the 4 sites). The second Magellan intersection point was off by 5 meters (north) from the Garmin, and off by 2 meters (east) and 5 meters (north) from the first Magellan. The 4 points used were sufficiently far apart (over 5 km) to make the minor accuracy negligent in the comparisons). The only thing I will say in regard to the one unit being so far off is that I took the readings across 2 evenings, and probably didn't allow enough time for the unit to settle down to a steady location reading. The second Magellan and the Garmin were tested on the same evening and at the same times, so the Magellan was set to the location, then the Garmin was averaged over 50 samples, then the Magellan reading was taken.

 

In the end, I came to the conclusion that the Magellan eXplorist 600 and the Garmin GPSMap 60CSx both exhibit similar accuracy levels, and that most of the time when I have troubles with finding caches, it is other issues causing the problems. The most common of these seems to be User Error, but other factors do tend to come into play like tree cover, and location (in gullies, etc). Now, I have noticed that the Magellan does seem to lose it's satellite lock a little more easily than the Garmin, but in the many hours of use, I have only seen it lose it's lock twice, but one of those was when the battery died, so that doesn't really count.