Enable High Accuracy GPS Collection
REQUEST: Could iForm bump the number of decimal digits for latitude/longitude/altitude from 6 to 8?
This would enable high accuracy (sub-cm) GPS collection with iForm and the myriad high accuracy BT GPS receivers out there. We and our clients want to use iForm to map power and irrigation infrastructure with an extermal GPS unit, often for features that are within a foot of each other. Currently, the 6-digit limitation equates to the best possible accuracy to be no more than about 7 inches (at least at the latitudes where we and our clients work).
Consequently, this small platform change would enhance iForm's usability greatly, particularly given: (1) the limitations with the BETA Esri Connector, (2) the fact there is an increasing trend towards high accuracy external Bluetooth GPS receivers for iOS/Android devices that enable day-to-day field workers to collect sub-foot and even sub-cm data, (3) that fact those devices are becoming more affordable, and more manufacturers/models are available each year, and (4) because expectations for higher accuracy field collection continue to increase. Don't want iForm to miss the market opportunity here because of a couple of decimal points.
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Hi Will,
Thank you for reaching out. So iForm captures the GPS data directly through the device OS. Phones and tablets just don't have the capacity to achieve that high level of precision. For example iOS can be as accurate as up to meters only. Only more robust surveying device or GPS base station might be able to achieve that. Can you please share with us what kind of GPS unit your clients want to use? We probably want to look at integrating that kind of devices with iForm and write the GPS data from those devices into iForm.
Penny
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One issue we've found with the iSXBlue and other units that can be used to supersede the built-in GPS is that even if you are getting sub-meter/improved levels of accuracy, the location accuracy as reported using the Location widget will only ever show an accuracy of 5 meters. This might be a limitation in how iOS Location Services reports the information, but it can be an issue if you are trying to demonstrate or verify the fact that you are getting high accuracy GPS data. I believe the ESRI Collector app is able to report directly whatever accuracy is being reported by the external GPS. I'm not sure how this works or how difficult this would be to implement though.
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Eric,
Yep, the iSXBlue II + GNSS (submeter) bluetooth GPS is one of several GPS/GNSS solutions we've used the last few years with iForm, and have had good success with it getting sub-meter stand-alone and even sub-foot when on the Oregon's ORGN (public RTK service). Unfortunately, although we routinely get 4-inch accuracy with the same unit, we "can't" when using the iForm app, due to it's rounding lat/long to 6 decimal places. That current decimal limit means we can't get better than about 7-8 inches at our latitudes, so sub-cm units are essentially incompatible to work directly with iForm (consequently users are forced to use one app for collecting the lat/long (e.g. Collector), and iForm for the attributes, then post-processing to combine). It sounds picky, but adding digits would translate to sub-cm accuracy with iForm when using sub-cm units, not to mention a more polished workflow (yay!).
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UPDATE: Sorry, i'm a little behind with my posts here... Will - thanks for confirming about the accuracy reported in the metadata.
Will - am I mistaken in my comment above about reporting location accuracy in the form data itself? I know the external units like iSXBlue have companion iOS apps that report accuracy in real-time, but that information doesn't make it into the data recorded by the Location widget.
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Kam - Yes, I think you're right that the accuracy estimate somehow isn't passed to iForm from an extermal GPS. My guesss is there's too much of a variety of hardware out there to support (perhaps that's why Esri has an explicit list of supported external GPS hardware for use with their Collector app). And yes, Geneq makes a companion RTN app for the SXBlue units that streams viewable accuracy metadata (and NTRIP corrections if using), but it's essentially just a real-time portal into performance (you can also set alarms when accuracy thresholds aren't met, which is handy), but no capture tools as far as I know. A fellow at Loggerhead Navigation mentioned in October that Geneq had plans to release a more robust "Utility" app to replace/substitute their current RTN app, with added functionality, but I don't know of a timeline for it or whether capture tools (including metadata) will be part of that toolset.
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Hi Kam, Will, and Eric this is great feedback, and ultimately it comes down to performing a deep integration with SXBlue technology (or the R1). The OS feeds us the location data as it stands today, and is responsible for the results you see.
In order to maximize the device, our software has to communicate directly with the external hardware, rather than using the OS as a translator (accuracy is lost). I went back through some emails and found discussions from 2014 that never moved ahead.
Does anyone have a good contact at Geneq that you can introduce us to so we can learn more? Feel free to shoot me an email at "truth@zerionsoftware.com".
Thanks much!
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Eric - we have not used any Trimble external bluetooth units. Besides the iSXBlue, we've used the GNSS Surveyor unit from Bad Elf, as well as the older Dual GPS units.
Will - would be great if you could post an update here once you've had a chance to test the new Catalyst. I'll do the same if we do any kind of testing, though we don't have any plans to do so at the moment.
Tony - thanks for chiming in, let us know if you end up making any plans on this issue in the future.
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Another interesting option we can pursue is to work with existing applications that already are developed on the market. If they want to work together, iForm and their software can communicate very much like this example using the third party widget.
https://iformbuilder.zendesk.com/hc/en-us/articles/204941284-iOS-3rd-Party-Node-Therma-and-Clima
The demo apps the hardware groups have already be published could follow the behavior in the Node example with about 4 hours of work and an app update on their end and ours. What would you think about that approach?
Kam: Would love to know more about what you would like to see. It seems there are many options available when I look around and your insight along with Eric, Will and others can help drive the focus. -
Is there any update to this post? We use Trimble R1, Arrow 100, and are looking at testing the Garmin Glo (or a similar solution). It would save a lot of time in many situations if we could use these directly with iForm instead of having to use collector for the points and then iForm for the rest of the collection. We've also used the GNSS Status iOS app with the receivers to pull coordinates.
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Morning Bekah, we have not made any progress on this topic but would welcome a group discussion around the devices you are currently using. Would you be able to show me how your current flow works together to see if we can come up with some fresh ideas?
In short we need to directly integrate the SDKs provided by the hardware manufacturers into iForm, or create a dedicated application that seamlessly sends the enhanced GPS data back to iForm (similar to the example with Node+ I mentioned above).
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