I had a quick question regarding coordinate systems for a survey project I’ll be conducting tomorrow. I changed the project’s settings from Emlid’s defaults to NAD83 New Jersey State Plane for my coordinate system and NAVD88 for my vertical datum. I noticed once I selected this that Reachview gave me a warning to make sure my base was also set to NAD83. I did a little research on Emlid’s docs and found this:
When setting up a base station on a benchmark, enter
NAD83(MA11) , or
NAD83(PA11) geographic coordinates (lat/long) and ellipsoidal height in the ReachView 3 Settings / Base mode .
I’m not seeing any field to change this in the Base mode tab, except for if I’m inputting manual coordinates.
I’m planning on getting my base coordinates through Average Single, logging raw data for 4 hours, capturing some GCPs with an RS2 rover through FIX, and then PPKing my base station logs through OPUS to get an absolute base position. Do I need to be concerned with setting anything up differently on my RS2 base when I won’t be inserting manual coordinates over a benchmark anyway?
Hi Theo, no need to worry about that message if you are using average single. This only applies when inputting a base coordinate manually.
Isn’t average single on the base WGS84 though?
I wrestled with this all pretty well over the last couple years, and I have to say for here in the states and for State Plane systems in general, the best way to do it is the following and works whether you stick with WGS84 or setup with NAD83+NAVD88.
Set up your base station anywhere and let it do average single for at least 30 minutes. Its similar to the Trimble “Here” function. Trust me on this one its just better to start new then donk something up doing conversions to a known point, especially because lord knows when the last time a BM was blue booked among other things.
Once set up, just go and shoot the BM. Ideally shoot at least 2-3 known BMs if you can.
Take all your shots and using the known BM coordinates and the shot BMs run everything through a least squares best fit adjustment using Trimble Business Center. If you don’t have TBC, even a CAD based “Align” command should get you a pretty good fit though you wont be able to measure residuals to give you a nice gut check.
Uh… yeah… most here probably do not. Trimble = $$$$$$
MicroSurvey FieldGenius is a good suggestion also. They have a free Windows demo that has a 30 point limit which you can use. The Android demo from what I understand is 30 days. The Windows version is complete… I do not want to move to Android version even as far as they have gotten, I don’t want to use a work in progress, when Windows version is complete at this point.
There are MANY Android Survey apps these days also… they all have there different quirks and learning curves.
QGIS also. I am not familiar with it though if it can do what you describe.
I’ve been up and down the last 4 months with back issues and been wanting to try my RS2 and FG. I got the FG and tablet about 2 months ago. Maybe this weekend. Sitting all day at computer in AutoCAD world really is frustrating some days. I’m a field guy at heart and some days I’d rather be fighting yellow jackets, hornets or wasps than in the office.
I am assuming no matter which coordinate systems are used on either end, that relative accuracy will still be maintained. So, anything he does at the base really wouldn’t matter. Unless there are other issues that could be brought in.
I am not convinced that the base crs changes anything anyway. I did a quick test where I used average single, then I took that coordinate and typed it in manually, then I converted to XYZ, all the while shooting in Ohio North. The greatest difference between the three datasets was 0.052 ft.
I know how you feel! I was in the field until I was about 27, spent 15 years in the office and went back to the field part time about 4 years ago. Now I hate being in the office because I always get stuck there. I have to make sure to get my flights done early because if I go in first I probably won’t get to them. We just hired a intern who already has his Part 107 license though so hopefully he will want to stay once the internship is done. Unfortunately that is probably going to put me back in the office more…
Yeah yellow jackets hornets and wasps are lame and all but have you ever come across one of these demonic insects?
Yep, those hurt too ! Those are giant horse flies !
I agree with the recommendations above.
You can do as you’ve proposed via an average single and then post-process your data.
Or you can manually input geographic coordinates (lat/long) and ellipsoidal height in NAD83 in the Base mode window of the ReachView 3 app if you have coordinates of the benchmark.
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