Basic Workflow for a Newbie?

We are looking at the Reach RS to help us lay ground control points for our drone jobs. We haven’t had the need yet to use one for that purpose but I have an interesting application that I think the Reach RS might be perfect for. Before I pull the trigger on buying the setup, I’m hoping someone can throw me a bone a summarize the necessary workflow so I can get an idea of how much work is going to be involed.

I’ve got a friend of mine that wants me to identify the GPS coordinates of about a dozen points in a flat one acrea area at a location in Henderson Nevada. It doesn’t have to be cm level accuracy, dm accuracy (within about 4 inches) should be good enough. He just needs the coordinates, I don’t need to actually mark or stake anything and it’s for a R&D project of his, nothing needing a licensed land surveyor stamp or anything. So as you can see, this would be a great job (I hope) for the Reach RS setup.

Having never used it, the first question that comes to mind is due I need to place the base station on an existing identified land surveying monument nearby or can I place it anywhere on the site?

The second question is, what is the work flow in general - how do I get the coordinates for each location and how long would it typically take? Is there a realtime readout I can use or do I need to go back and extract the information after doing some processing on the data?

Thanks in advance for throwing me a bone on this.

From what you describe I think RS+ would be a great solution. One caveat would be it does take a little more thinking if you are needing state plane coordinates and/or local surface benchmarks. The Reach receivers shoot WGS84 and ellipsoid for elevations. You can accomplish all off this in the Reachview iOS/Android app.
That being said, I would get familiar with QGIS. It is a free GIS program that will allow you to bring in the points and/or drone map and convert them to your local state plane coordinates. An alternative to QGIS would be to purchase a different app or a survey-grade data collector that will allow you to localize what the GPS shoots to local benchmarks and control. Personally, I use Topcon Magnet Field on an FC-500 data collector. If you end up going with the Reach solution I would definitely recommend eventually getting the Topcon setup. It will pay for itself quickly.
General workflow is go through the initial base/rover setup which there are good videos for and then get familiar with all the settings. Once you feel good about it just setup the base anywhere and let it collect coordinates for at least 10 minutes. Once it has established a good base coordinate you are ready to shoot. If you are having trouble acquiring a fix (RTK) there are a number of things to troubleshoot, but I have been able to prove that even a good float and 2-3 minutes is good enough to get 7cm or better accuracy. There’s always the post-processing (PPK) method, but I don’t have time for that and don’t need much better than a tenth of a foot for the drone, but luckily I have Topcon receivers for sub-centimeter accuracy. All your points can be exported in the most common formats straight off you device.

2 Likes

Hi @consultant,

Do you still have any questions after @chascoadmin reply?
Feel free to ask.

It sounds surprisingly straight forward. Is it really that simple to just place the base, turn it on, wait 15 minutes or so and then go around to each location with the remote station and set it there for 2-3 minutes? Then export the coordinates (WGS84) to a file (or record then manually as we shoot each point.) We don’t have to signup for any local network in the South Nevada region for the base station to connect to (for RTK?) 7cm or better accuracy is exactly all we need in WGS84 coordinates.

Do I want the Mapping Kit? RTK Kit? or UAV Kit? Will use this mostly for doing ground control points for UAV work (7cm accuracy is fine) I’m assuming one of these kits and either a couple tripods or a tripod and a survey poll?

It sounds like you will want the base/rover (Mapping/RTK) kit unless you want to find someone on here that has adapted the UAV module for your drone model. You will not need a network subscription for this.

If you are fine with WGS84 coordinates and the ability to translate them to true state plane coordinates then it is that easy. It becomes more difficult when you need coordinates that may not actually be on the EPSG because they were moved in the CAD or have a scale factor. This is where you need to localize and be able to use a custom coordinate system in your drone image processing software. Localization also takes care of the discrepancy between ellipsoid heights as provided by the Reachview system and what may actually exist on the ground.

One of the things we want to measure is the coordinates for a couple parking spaces inside the parking space lines. We can’t use ground control points in combination with a Drone GeoTiff image of the parking lot due to flight restrictions at this particular area. Considering the width of the line is close to the margin of error, is there a fairly simple way to instead of shooting the 4 corners of the line just shoot the endpoints of the line in the middle and then have the software calculate two additional coordinates with a 2 inch offset to either side of the point?

Someone may correct me, but I have not seen the ability to draw objects or create point offsets. You would be better served in QGIS. Additionally Magnet Field can. All linework and offset points can be generated on the data collector and export as a DXF CAD file. To compliment there is Topcon 3D Office which is free and allows you to use this data on a desktop. It is capable of bringing in the points collected in Reachview. You can also stake off of said linework.

Yes, place the base, average its position, start sending corrections on the rover, survey, download raw logs, post-process.
If you fill base position manually with known coordinates, you can do without 2 last steps.

For placing GCPs, I’d recommend Reach RS+ Survey Kit.
Unfortunately, you’ll need to buy tripod and pole separately as we don’t sell such accessories.

Regarding this workflow, it’s better to use QGIS or CAD as @chascoadmin advised.

I would recommend buying two survey poles and these. The survey pole and tripod attachment will be much easier to manage, center and level than a traditional tripod.

https://www.tigersupplies.com/Products/Seco-Construction-Series-Thumb-Release-Bipod__SEC5217-40-FLY-.aspx

https://www.tigersupplies.com/Products/AdirPro-Aluminum-Prism-Pole-Tripod__ADI761-00.aspx

Would a “next step up” on the remote and control unit (ie, Topcon Magnet Field + FC-500 data collector) really save me that much time considering I need to survey on average probably 5-8 points on a job with 3-inch (7cm) accuracy and I probably need to do this maybe 10 times a year at most. I took a look at that Topcon stuff and it’s a lot pricier. I also read a thread in some other forum kind of poo poo’ing the Reach that it is ‘single frequency’ but I’m guessing these are just Land Surveyor’s used to paying 5-figures for equipment and now new technology is bringing the price way down with speed and accuracy that is adequate for most applications? I’m sure the “expensive stuff” still has it’s place but maybe a shrinking place. But I don’t want to go off on a tangent. I think my research conclusion is still accurate in that (a) this is more than adequate for my use and (b) it sure represent a relatively better value (aka bang for the buck) relative to much more expensive equipment.

I think with that amount of usage a good first step would be to get familiar with Reachview, coordinate systems and how to get your points into QGIS. Learn how to draw in QGIS and then be able to export that out for other programs to analyze. The receivers should be plenty capable of 5cm accuracy. Single frequency is definitely a big roadblock, but Emlid doesn’t quite get that yet because the gap in use-case and type of data between the UK and the US is just now becoming apparent. The UK is much more global and the US is regioned which creates more locally accurate surveys, but also a big headache in understanding projections and translation. I still don’t understand why we can’t go back to metric…
As far as these units competing with professional grade survey/construction receivers, I don’t see it happening any time soon. The Topcon units we use are so far superior in ease of use, speed and accuracy that in order to get close these units are going to get more expensive. Not to mention that the machine control industry is built off the Topcon and Trimble units.
The Emlids are the new generation of GIS grade hardware which use to be sub-meter that is now centimeter. With survey grade I can shoot in 3 seconds what I can shoot with these in 2 minutes. They are good for my drone photogrammetry and its capabilities for now. I am keeping in mind that with my extra time spent I will have paid for a $30k Topcon setup in no more than 2 years. I shoot about 300-400 GCPs a year.

2 Likes

I can tell you that the Reach RS units are awesome! I can also tell you it was a VERY slow and painful road to learning and comprehending the GCP data collection. And more specifically the post processing. Acquiring photos and using software to stitch them is what I would call the easy part. From the very beginning there were some VERY helpful users here on this forum (Tore and Bide were the top helpers for me at the time). But even with all the help I still could not learn RTKLIB for post processing. So I now use the Reach RS units and EZsurv software. Best move I ever made.

I just published up 2 short videos on processing data from the Reach units (using Reachview survey). Sometime this week I will have a full length tutorial (start to finish, nothing left out) on collecting and processing GCP data. That video is aimed at helping the folks who are brand new to GCP’s and post processing.

Here are the 2 short videos that I just did


Tim

2 Likes

Nice vids. Just a shame you are using EZsurv, as it costs almost the same as 2 RS+ units. Not really in line with the low-cost solution that is the Emlid products.

I find RTKlib tools much easier and more modern in the way it presents data, but of course lacking the stop-and-go survey workflow, that EZsurv has implemented.

Hey Christian, there are no doubt alot of users using RTKLib who are very happy with that. When I looked at what EZsurv provided and how easy it was to use, I found it worth the investment. I would do it again today.

As far as RTKLib goes, I know it has to be good software since there are many people using it. But at least when I got going, there was no training videos that walked through every single step, beginning to end on collecting Ground control points. Folks who are not surveyors do not understand it the same way that surveyors do. If there is still not that kind of video available, maybe someone will do that so they people can at least see how it is done in both software solutions (one being free which is always nice). I will post a link to my full video when I get it done so that at least it will be out there as an option.

As always, I am thankful for the great resources on this forum! Take care.

I think that is indeed why I find EZsurv so convoluted. So many terms taken directly from the surveying world, and the workflow being illogical :S
In my opinion it needs a massive UX and UI effort. It has so many nice details, but they drown in the complex flow (and in the price).

1 Like

rather I think that the developers are more entertaining today in trying to solve so many failures that give updates. that should have a team to develop video training from several points of view from the newbie to the master because exposing their mistakes and trying to solve in a group is tedious

So essentially to get quicker reads you need to go add a zero to the end of the Reach price? (And then some?) One of the earlier replies confused me a little as it sounded like the Topcon was a replacement for just the rover used with a Reach base which I assume is not the case.

Correct, it was the Topcon Magnet Field software which was being referenced. There are embedded Windows mobile and PC versions. The embedded version is for their data collectors whereas the PC version could run on a small Windows tablet. I have an old Dell Venue 8 Pro. I use a Topcon FC-500, but I need to try running it in training mode on the Dell to see if it allows the functionality without purchasing the full licensing. I will try to do that soon and report back.

Magnet Field is much more comprehensive for the actual surveying aspect of the process and does internal post-processing, it is not as deep or configurable like EZSurv and RTKLIB. One thing that it does provide, that I think is most important, is localization. In my opinion the use-case for the Reach receivers and units-of-kind for general land data collection (I want so surveying) is fine, but when you get into real value in construction you will need localization and the ability to integrate with other design softwares. What your client doesn’t know doesn’t hurt them right? Until it hurts you when they find out…

Well realistically over the next one to two years, my most likely usage is going to be probably a dozen (one a month) jobs where I need to survey 5-15 ground control points with decimeter accuracy and no localization necessary (just WGS84 is fine.) It’s mainly for when doing large area jobs (250-1000 acres) flying the drone at max altitude (400ft) to tighten up the RMSE but this won’t be for engineering or precision construction needs, hence the DM accuracy should be sufficient without having to spend a ton of time to get fixes with the rover. It sounds like two Reach units with RTKLib will be able to get me where I need to be at the lowest cost possible. If there’s something that would significantly improve workflow efficiency or accuracy (like better software) but with only a modest increase in cost (like no more than 25%) I’d consider it, but 25% of like $2K isn’t much to work with.

Sounds like the Reach solution as is will be great for your use-case then! If you can achieve and RTK fix there would be no need for post-processing for that level of accuracy. It’s good to know just in case though.

1 Like