Handheld GPS advice

Hi Folks,

First post here, so please be nice :wink:

Lately I’ve also started getting addicted to mapping and was wondering if it is worth purchasing a dedicated GPS. Now let me finish…

I do have an iPhone 4s that I’ve used on the odd occasion for track logging and importing that to OSM. I have heard that the GPS accuracy it gives is pretty darn good. However, I still feel there’s not enough accuracy. The question is: Is there much better accuracy to be had with a dedicated handheld GPS (such as the Garmin eTrex 10, don’t have too mund funds available unfortunately)? I am aware of the usual pros and cons of phone vs dedicated (waterproof, rugged, etc.), but from a purely GPS log accuracy point of view, is there much to be had by getting a dedicated logger?

Thanks so much and best wishes,


Hello there. I don’t have a iphone but an Android smartphone which I’ve compared to my wristheld GPS Garmin Foretrex 301 (which is quite cheap and simple). During good conditions (standing still in an open area) the two units give similar results, but the smartphone is much more sensitive to the conditions. So if I enter a forest (and I do a lot of walking/running in the forest) the smartphone is really lousy compared to the separate GPS.

When I check the GPX tracks in JOSM (for instance), the tracks from the GPS is much more smooth than those from the smartphone.

So my recommendation is to get a separate GPS unit. The GPS chip in itself may perhaps have the same accuracy as the smartphone, but the antenna and other factors are also important. If you want to get a GPS with the main purpose of mapping for OSM, have a look at the wiki pages which contain lots of useful information about different GPS units.


Do you need the high accuracy at all? This depends where, what and how you are mapping and the quality of the Bing imagery of the area.

If the area is rather flat and the Bing resolution is high enough to draw all what you want map you will need a GPS mainly to detect and adjust an offset. For the offset the best is to have GPS tracks from different devices and different dates. One track might still have a systematic deviation due to the specific device and atmospheric conditions at the date tracked.

For georeferencing photos and audio you don’t need higher accuracy when you stop to take them and can take the position from Bing.

I would just try it with the device you have already. First get some experience and find your preferred method before investing in equipment which might not be really necessary. And even a less accurate object ist still better than no object on the map.

Personally I think the iphones are good enough, but if not the garmin handhelds are probably considerably more accurate yes. But I do wonder if the 4s is compatible with some external GPS receiver? Should improve the accuracy when not using the internal antenna!