GPSrChive Discussion Forum

Now that the H1i / H1i Plus have been out for 9 months, and the device having received multiple firmware updates, including updates of the GPS firmware, I'm wondering what kind of accuracy numbers others are seeing?

Coming from a GPSMAP 66sr and GPSMAP 67 (as most recent GPSMAP devices), I notice that both devices consistently displayed an accuracy of 1.8m in good conditions and with multi-GNSS and multi-band.

With my H1, not so much.

I usually have my device on Auto Select. When it's in multi-GNSS mode without multi-band, I get 3.0m as the best accuracy. The device receives satellites from GPS, Galileo and BeiDou, with around 10 satellites. Usually BeiDou has a bit more than the other two systems. And I noticed that with 10.13, there's no GLONASS reception.

When the device uses multi-GNSS with multi-band, I usually get no better than 2.3m but mostly 2.4m - 2.5m in my local test walk (in a neighborhood with low-rise housing, and some open areas, around latitude N52 and longitude E05).

So what are the experiences of other H1 / H1i users?

I have all systems and multiband enabled. I live in Scheveningen (N52 E004). I can see GPS, Galileo, and BeiDou, but no longer GLONASS. At the beach near the Zandmotor, I had 1.9-meter accuracy—which is a very open area by Dutch standards. If I go to Scheveningen beach, it’s 2.3.

Dutch

Bij staan alle systemen plus multiband aan. Ik woon in Scheveningen N52 O004 . Ik zie GPS, Galileo en Beidou, Glonass dus niet meer. Op het strand bij Zandmotor had ik een ontvanst van 1,9 meter, dat is wel een zeer open gebied voor Nederlandse begrippen. Ga ik naar het strand van Scheveningen dan is het 2.3.

Dank voor je reactie

I haven’t seen 1.9m myself but good to know the device is capable of that accuracy!

I wouldn't look that match for comparing the values showed on the satellite view.
They don't show you how accurate the readinds are, but rather how "precise" position readings are (it is not the same).
You may compare that to the two thermometers, one has a scale by 1 degree, the other by 0.1 degree. But the first one is very precise (so if it say 20 degrees you may be sure that it is exactly 20 degrees), the second not so (so if it shows 20.3 degrees, in fact it might be either 18.3, 22.3 or something in between).
It looks like the second one is better (it shows the values with the precision of 0.1 degree), but in fact it may be much more off the real value than the first one.
The same goes for GPS, it may show you precision of 1m on the satellite view and still the position will be coupble of meters off the real one (not accurate).
Also the attached picture may be helpful to understand the difference.

To see how accrate the GPS is, it is better to see how the saved track match real position.
I didn't compare H1 with 66 or 67, but in comparison with my old Oregon H1 is much more accurate - Oregon has more tendency to "crawling" when left in the same place, and it can be off by 1-3 meters in places where H1 is exactly on the track I am walking/driving.