GPSMAP 67 GPS accuracy

[Nail]

I agree the time doesn't matter, I just have my JNX files because they are in a batch, you can't separate them, I don't have a KMZ because I have the JNX, I had tried the KMZ but the displays are longer than the JNX. My other Garmin topos maps are all disabled.

Are you using JNX in 67?

[mimichris]

I agree the time doesn't matter, I just have my JNX files because they are in a batch, you can't separate them, I don't have a KMZ because I have the JNX, I had tried the KMZ but the displays are longer than the JNX. My other Garmin topos maps are all disabled.

Are you using JNX in 67?

I don't have a 67 but a 66sr which is the same apart from a few novelties on the 67. and I'm interested in following the 67 and its evolution.

[jrlockerby]

Regrading the estimated error on the receiver, it's value is relative (open sky I presume) and not absolute (most of the time). RINEX analysis is useless so far (but Garmin admits this is a side feature and outside its intended scope of use). Within its scope of use I have done some initial tripod tests (good skies) recording a track and compared with the 66sr (in one case at the same time at the same location. I observed the following differences:

1. DRMS is ~15% better in the 67 (~1.1m vs ~1.25m).
2. The track point distribution was more even in the 67. The 66sr has noticeably more error in the north-south direction versus east-west.
3. The 67 has fewer outliers. The maximum error from the mean was always <3DRMS (so far) while the 66sr was generally ~3.5-4 DRMS (but has been as momentarily high as 5DRMS in the same location during past recordings).
4. When calculating the mean, the 67 was closer to true position. In one 24 hour side by side comparison, the 66sr was off by ~60cm where the 67 was only off by ~15cm. This needs more tests however to be sure. The atmosphere may have been favorable and I have only done 2 tests (a month apart).

My initial assessment is yes, the 67 is more accurate. I suppose if you are making a measurement, every little bit helps, but if all you are doing is outdoor navigation - which is what the unit is designed for, the improvement will be unnoticeable.

In a few months, I will have a more comprehensive assessment of its accuracy (hoping Garmin fixes the RINEX logging issues).

[JungleJim]

This is great info, thank you for sharing jrlockerby!

[mimichris]

And yet this study gives the 66sr to within 3cm....Have you read it?

Spoiler

https://www.gpsrchive.com/Discussion/vi ... php?t=2298

[neilwoody]

I have used my 67 for about a month now and am very happy with it. The battery life, screen sharpness and positional accuracy are all excellent. I use ExpertGPS software to plan my off-trail routes and manage waypoints and tracks. I use Garmin Express or Garmin Connect for firmware updates and EPO/CPE updates. I evaluate the positional accuracy using hiking trails and roads of the latest USGS 7.5 maps (uploaded using the Custom Maps feature) and it is spot-on. Using the GNSS and multiband settings, I achieve a steady accuracy of 6 feet, more than enough for off-trail wilderness navigation.

[mimichris]

I have used my 67 for about a month now and am very happy with it. The battery life, screen sharpness and positional accuracy are all excellent. I use ExpertGPS software to plan my off-trail routes and manage waypoints and tracks. I use Garmin Express or Garmin Connect for firmware updates and EPO/CPE updates. I evaluate the positional accuracy using hiking trails and roads of the latest USGS 7.5 maps (uploaded using the Custom Maps feature) and it is spot-on. Using the GNSS and multiband settings, I achieve a steady accuracy of 6 feet, more than enough for off-trail wilderness navigation.

I think updating CPE and EPO files is done like the 66sr with WiFi, If you are connected at home to WiFi, the update is done automatically.

[Willie]

And yet this study gives the 66sr to within 3cm....Have you read it?

Spoiler

https://www.gpsrchive.com/Discussion/vi ... php?t=2298

I read it. You couldn’t write the same article for the 67.

[mimichris]

And yet this study gives the 66sr to within 3cm....Have you read it?

Spoiler

https://www.gpsrchive.com/Discussion/vi ... php?t=2298

I read it. You couldn’t write the same article for the 67.

I didn't write it, I just found it on the web. I don't think the 67 can be tested as the 66sr was because the RINEX file of the 67 is corrupt, Garmin must make a modification, well I hope.