Convert PPK back to state plane

Reach Module / M+ / M2 RTK / PPK configuration
1

Since Emlid takes my referenced data and converts it back to Lat/long HAE when I post process, no idea why they would do this as it completly nullifies the use of collecting in anything else, I need to convert it back to state plane and NAD88. Ive read everything I can and there doesnt seem to be clear answer besides try this software and that software. Emlid even told be to use ARCMap, which does a horrible job (over foot error) and ARCMap doesnt do vertical with any measureable accuracy.

So I am asking anyone if they have done, what they used and what the file format is to use it. I have hundreds of points daily and doing them one at a time is not an option. I need to batch convert. Any help would be appreciated.

1 Like
2

What is your correction source?

1 Like
3

Corrected from emlid base station over known point using emlid studio.

4

What coordinate system was the known point defined it?

1 Like
5

The base if fine. When I get fix everything is as it should be and pretty much dead on. My issue is after I PPK it. Emlid, for some unknow reason to me, outputs the ppk files as WGS lat/long and HAE meters for vertical. It doesnt register or save the state plane coordinates. So I need to take the WGS output of the ppk and do a conversion back to washington state plane south NAD83(2011) Feet NAD88 Feet. I am looking for a program that I can feed the Lat/long HAE into and convert it back to state plane NAD83(2011) NAD88 for my GIS guys. Something I dont have to do a point at a time manually.

6

If your Base is in NAD83, your rover will be as well. Emlid Studio (or RTKlib, which it is built upon) cannot and does not transform from one coordinate system to another. It simply doesn’t know anything about coordinate systems.

2 Likes
7

It only corrects in Lat long HAE. Emlid confirmed this with me this morning. So I need to get back to state plane feet NAD88

8

It changes the the representation of the coordinates, but it doesn’t change your coordinate system to WGS. So you simply need to convert (not transform) your coordinates back, and then work out the undulation using a geoid model or similar (RTKpost can actually do that automatically, if provided with the geoid model).

9

Ok Maybe I am not being clear. I fully understand that Emlid Studio does not convert coordinates. It uses the coordinates of the emlid as wgs84. Because that is what the raw rinex files are recorded in. I completely get that and that is not my issue. My issue is when I get the corrected points back out of Emlid Studio they are in Lat/Long HAE Meters. I can not use that for my data because it is not the coordinate system my customers use. And it is approx 4.2 feet off horizontally from the coordinates I need it in. And I definitely cant use elevation in HAE Meters. Meters to my customers is like studying a moon rock. They don’t care and cant visualize meters. They work in feet.

So my question is. Is there a software where I can load a points file with the Lat/Long HAE elevations, and convert it to state plane feet NAD88 feet? As a batch file instead of doing NGS to convert horizontal and then doing Vdatum to do vertical.

10

It does not :slight_smile: Your rinex is not recorded in any particular system as such. Your base coordinates dictate that, and those are again dictated by whatever your known point is defined in.

You have to convert these back again, but only numerically, not as a transformation from one system to another, then you will indeed get an offset, as you are “double-applying” your coordinate-system.

So if you have a large amount of points for conversion, Emlid Studio is probably not the right tool for you.
With those requirements, I would suggest to look into more commercial software, like i.e. OnPoz EzSurv. There you define the systems before processing, and get results in the same system.

1 Like
11

Im just going to leave this with Ok. I dont think you understand what I am asking. It has nothing to do with Emlid Studio. Ill see if I can rephrase this better. Ignore anything that was said before.

Is there a software that can convert from Lat/Long HAE meters to State Plane Feet NAD88 Feet. Without having to do it one point at a time manually or having to convert Horizontal in one software like NGS and then got to something like Vdatum to do vertical? Forget that its even Emlid or anything. Lets pretend im using a solar transit from 1854.

12

Here’s what I use occasionally, but I understand what you are saying

https://www.ngs.noaa.gov/NCAT/

Make absolutely sure you know what datum/projection your beginning points are in. Garbage in/garbage out. You can upload an ASCII point file in a specific format.

This has been one of my arguments for Emlid to change their basic setup of their receiver/software for professional Land Surveyors. They have now had their coordinate projection system up and running for a while.

As I have suggested a few times, they need to make their base setup more user friendly for land surveyors.
I don’t want to see geographic/ellipsoidal coordinates at the base, it’s no use for the land surveyor if doing any kind boundary/construction work. It also causes concern and questions setting up your project.

I want to see my selected datum/projection system/units of measurement at the base !

If you’re starting a project, select the appropriate datum/projection system, select your appropriate geoid model, and do a “here” position (+/- 1 m) and average as usual and take off making measurements in the selected system. You know you are confident in your work as you’re in your selected local system. Not some non-conforming geographic/ellipsoidal system.

Same setup if you upload an ASCII point file for the field, except that you can now select a previous field located point for the base, input the ARP and use the uploaded “design” points for layout or searching.

There’s no need for Emlid’s methodology for the base setup… they have the datums/projection systems/conversion routines… use them setting up the base !!!

Get with the program Emlid or be prepared to lose the prospective market in the USA, not only for land surveyors but also for amateur photogrammetrists. This is a great entry level system you have for the non-geodesist land surveyor who is looking for a low-cost, entry GNSS system.

I’ve been in this profession most of my life and a licensed professional Land Surveyor for over 35 years.
I know what I’m talking about.

Last warning

3 Likes
13

QGIS might help.

1 Like
14

Not sure if this is what your looking for, but maybe try this website:

Convert Latitude and Longitude to State Plane

I have used them only for a single point conversion task, but they do offer batch processing for a $50.00 yearly fee.

18

Hi Mark,

We’ve been communicating with you via email. I’ve written you there. Also, I want to confirm in this thread that Emlid Studio can provide only geographic coordinates. After post-processing, you’ll get the rover’s coordinates in the base’s datum. So, if you set the base in NAD83, the result will be in NAD83.

Emlid Studio is an emerging software that was released quite recently. We understand there are features that can level it up, including output in different coordinate systems and vertical datums. However, this feature is highly complex and requires the support of all the transformations and geoids on a new basis. That’s why it’s not in our near plans.

2 Likes
19

How are people setting the base datum when there is no option to do so lol

This is what is confusing people “make sure your base is in the right datum etc etc”

There is no option for that

The workflow for Emlid currently is all over the place. The first thing you should see when you open the app is the project screen, fill in the details there, set your datum which now applies to both base and rover then you can continue on to your settings menu then on to the base for setup then back to rover to continue the pickup/setout

20

Hi Cameron,

When you enter the coordinates in the Base mode tab, they are already in some datum. If you get a known point from an official source or connect the rover to an NTRIP service, it should be possible to check the datum there.

ReachView 3 can project the coordinates, but transformations between different datums are not currently supported. That’s why it’s essential to set the base in the datum shown in the note.

1 Like
22

I agree with that!
EZSurv is an excellent software to post-process accurately & efficiently! EZSurv counts over 30 years of success in surveying, geodesy and few years in the field of UAV’s.

• EZSurv allows the use of your Country reference frame (Datum, projection, local grid and vertical surface/MSL). All USA state plane projections are available as well as USA vertical datum grid (geoid model). Obvioulsy, the type of unit can also be configured (meter, International feet or US Survey feet).
• For drone mapping, it allows to interpolate a position for each photo based on your drone configuration and to write PPK position directly in the photo Exif, thus eliminating data file manipulation.
• For land surveying, EZSurv is a complete solution for static, rapid static, stop&go and kinematic surveys. It includes QA tools and least square adjustment.

https://effigis.com/en/solutions/onpoz/ezsurv/

2 Likes
23

Hi Mark

EZSurv would definitively be an efficient software for you as it would directly output directly what you need!

1 Like
24

This topic was automatically closed 100 days after the last reply. New replies are no longer allowed.