@ipswichMapper For the vast majority of contributors, the precision of the standard smartphone is not important. As you say, when routing over OSM data, navigators are quite tolerant of variances in where the road is in the database versus where the navigator thinks it is. This is generally invisible to the user thanks to navigators preferring to snap to the closest road, although sometimes it gets it wrong when there are two roads very close to one another and the user will see themselves bouncing between two places.

I think this where the beauty of OSM and iterative mapping comes through. There are tons of different type of contributors and a single contributor doesn’t need exhaustive knowledge or the best-in-market tools to add to the map. For a given feature, you have the initial contributor who is happy to get the feature on the map. Then there’s the contributor who refine the tags to be as detailed as possible. Perhaps another correctly adds the feature to a relation and finally someone surveys the exact location using equipment costing thousands of dollars. This refinement continues throughout the life of that feature.

For me, contributing to OSM is an excuse to go outside and survey the location in person. As such, most of my recent contributions include modifications to hiking trails or outdoor locations. For trails, precision of the GPS device is important because there often aren’t references like streets or buildings that can be seen from imagery: all I have is my GPS track and perhaps something in a clearing among trees. Precision is also important to me because I want my contribution to be as accurate as possible. I like the idea that some hiker could look at the trail in Alltrails or some other app and see themselves right smack in the middle of the path that accounts for the small zig-zag the trail just took.

Regarding imagery, the recommendation to check the tracks is more helpful in cases where the imagery or the surrounding OSM road network is not-yet-up to date. If tracing from imagery in a newly constructed area, it can help to be a sanity check of where things may actually be when there a bunch of traces in the area. The variability of public OSM traces illustrates exactly what I wrote about in these three diary entries and your comments about the doubtful precision is exactly the reason why I wanted to share what I’ve learned. To those who are interested, they may use the information to increase the precision of their traces.

In all, I think it’s perfectly fine to rely on the accuracy of a smartphone for contributions. In fact, with multi-GNSS and mult-band chips becoming standard, in 5 years the average smartphone likely will be just as precise as dedicated location devices. There are as many individual interests as there are contributors. Take a look at the feature proposal page or one of the tagging mailing lists to see these diverse interests. Eventually someone will come along who gets a kick out of refining the accuracy of a feature from ~15 meters to ~1.5 meters.

For OSM as a whole however, its authority will depend on its overall accuracy. This authority is what impacts if it gets used in commercial applications or any situation outside of a hobby database folks contribute to in their free time.

@philippec Which terms did you find unique to Garmin? While initially researching the device, some terms are indeed Garmin products, but others were generally available words. If you’re talking about RINEX, it’s a data exchange format like GPX not unique to Garmin devices. I had first heard of it for this device and I’m eagerly awaiting its activation. Here is the Wikipedia page for RINEX.

@Dzertanoj You are absolutely correct this was not a scientific survey. Nor was that the intent. When dealing with GNSS location data where one must be absolutely confident in the accuracy of a survey, at least two devices are necessary (as seen from professional surveyors) to account for exactly the interference you described. This article series relayed my personal experience when using only one device that is relatively available to the average OSM mapper.

By comparing the tracks created by three devices recording at the same time, it shows how the devices respond during the same atmospheric and meteorological conditions. Differences in the track are more likely to be due to each device’s properties and their processing rather than variances in atmospheric conditions. I did omit details how each device sampled location data at one second intervals, but I’ve added that in based on your feedback.

I do not present these devices as substitutes for professional surveying equipment or teams when you need to know where exactly a specific coordinate is on planet Earth. Instead, these accounts are my experience as a hobbyist contributor to OSM for others who may be wandering into the single-device accuracy rabbit hole as I did.

Regarding post-processing the information, this is the next area I’d like to discover. As far as I know, neither the S10e nor the EcoDroidGPS make available their raw satellite observations for post-processing against data provided by continuously operating reference stations. The 66sr should be able to provide this data through RINEX logging, but this feature is not currently available in the firmware. Do you have information on how this is done? I would be super interested in learning how RINEX logs are processed to further increase accuracy.

@ChristianA The eTrex uses only two satellite constellations at a time GPS and GLONASS while the new units can use GPS, GLONASS, Galileo, QZSS, and IRNSS (QZSS and IRNSS are only applicable to Asian countries). In addition the GPSMAP 66sr and the cheaper GPSNAP 65s both use multi-band and multi-GNSS for positioning. With more satellites at its disposal and an external antenna stub, it should absolutely be more accurate than the eTrex30.

With that being said, I’d recommended waiting on getting the dedicated Garmin devices with multi-GNSS until the firmware improves a bit. While the unit is quite accurate in its current state, I don’t think it’s worth the price tag if you primarily will only use it for mapping. If you’ll use the navigation features while hiking or other outdoor activities it may be worth it and the precision would be a bonus.

The 66sr specifically is expected to gain RINEX logging which means that data can be pulled from the device to achieve nearly centimeter accuracy with post-processing, but this is not yet available despite what is listed on the Garmin product page.

If you’re up for a smartphone upgrade, see if any of the new phones you’re weighing have multi-band or multi-GNSS. I would guess you’d see precision like you see from the green EcoDroidGPS tracks in this article.

@Samderd17, you’re absolutely correct. For most, gaining access to centimeter precision is extremely expensive and cumbersome for the sake of contributing to OSM. There are some affordable commercially available solutions using RTK and I’ll be talking about those next.

For the most part, my experiences are directed towards those who only are using one device, but still want a decent degree of precision.