swells:
Hey samruru,
No worries, everyone is a newbie at some point! One thing I would suggest is that you build a list specific constraints:
How fast will this device travel? How good to you need the accuracy to be? How are you going to get RTK corrections to the device? Do you want to hook it into an existing system? Do you want something that works out of the box? Having a list like this will help you narrow down on which device to use.
We have a lot of content that can help you learn more about this subject, and maybe give you some ideas to get you started!
https://www.sparkfun.com/news/tags/rtk
1) What would be the best components to put together to be able to build an RTK rover that we can connect to a smartphone and use for 3D scanning?
This depends on what you mean by 3D scanning, and how much design and customization you want to do. RTK is most often used for surveying type work, to mark out a list of very accurate GPS coordinates. I’m guessing from your question that you want to build a surface map of some terrain, basically attach a GPS to an RC car, run it over an area and create a map? We have a line of “finished goods” type RTK products, which are already engineered and programmed and ready for use; this would be the fastest way to get up and running in grabbing GPS data. If you are interested in modifying how it works, integrating it electronically with other devices, etc, we also offer the breakout boards.
Here are all of our RTK products: https://www.sparkfun.com/categories/tags/rtk
An important thing to consider in selecting a device is how to get the RTK corrections to it. RTK for a mobile GPS receiver (called a “Rover” in GNSS parlance) requires giving the receiver constant corrections so it can get a precise fix on its location. For example, the [RTK Express would require either a Wifi connection to an NTRIP Caster, or for you to have an app on your phone that connects to an NTRIP Caster and sends the corrections to the device via Bluetooth. On the other hand, the [RTK Facet L-Band can receive corrections via satellite, so it doesn’t require internet access.
2) If we were to create our own 3D scanning app, how difficult is it to integrate the positioning data from the RTK rover with the 3D scans captured by the mobile scanning app?
GPS devices output NMEA messages; there are a bunch of different types of these messages, some telling your Latitude, Longitude and Elevation, some telling which/how many satellites are in view, some telling your current level of precision. A GPS app like [SW Maps will parse these messages, extract the position data, then draw a dot showing that position. To design your own app, you would use a similar technique. Parsing the messages and extracting the lat/lon/elevation is not too difficult, the messages and syntax are fairly simple. I think the hard part would be how to integrate that data with whatever scanning data you are developing. Additionally, I think you would need some high accuracy Heading data from a magnetometer that tells you which direction your device is pointing in.
3) Would you know any 3D scanning mobile apps that are available and able to integrate the RTK positioning data?
I haven’t seen any.
[/quote]
Hi swells, thanks for the reply here!
Basically, my company is wanting to start a 3D scan to augmented reality pipeline. We’d 3D scan a preconstruction site that is geolocated (using an RTK rover and smartphone app, ideally) then overlay our proposed equipment models on top of the 3D scan so that our crews can view the as-design equipment accurately on-site via AR on their smartphones. I hope I explained that clearly haha.
Easily enough, we can use a viDoc RTK rover and Pix4D software for this, however we’re looking at all the possible avenues here and wanted to know how feasible this would be for us to just create ourselves. Another end goal for us would be to be able to integrate this pipeline with our own already existing project management platform.
Some more info: we’re a project management and consulting firm for telecom so we do not have a ready team yet specifically to build this device and mobile app. We’re basically starting from the ground up. How long would you think this would take us to create and get it usable enough to offer as a service for clients?
Hope I gave you enough info for some more of your insights 
](https://play.google.com/store/apps/details?id=np.com.softwel.swmaps&hl=en_US&gl=US)](https://www.sparkfun.com/products/20000)](https://www.sparkfun.com/products/18442)
