Emlid Flow · CRS Configuration · Localization

Creating Custom Coordinate Systems and Localization in Emlid Flow

Video Tutorial Custom CRS Site Localization

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This video will show you how to create custom coordinate systems in Emlid Flow and Emlid Flow 360 when you know the parameters of the system you would like to use. This will also show you how to use the localization feature and create a custom CRS from that localization if you have an Emlid + Survey subscription.

Configuring Custom Coordinate Systems via Known Parameters

We will first create a custom coordinate system (CRS) in Emlid Flow and Emlid Flow 360 using known mathematical parameters, then move into the local calibration workflow. Inside the cloud platform of Flow 360, you can build your custom CRS directly in the management options under your profile menu. Alternatively, much like the mobile app layout, you can create it on the fly when selecting your spatial parameters during a New Project initialization.

For this walkthrough example, we use the specific coordinate values published by the Ohio Department of Transportation for their new low-distortion county projection framework, which isn't yet native to the default Emlid lookup library. Because our core office operations are centered there, we demonstrate mapping out the configuration parameters specifically for Summit County. This structural configuration layout mirrors the setup window you see on your mobile hardware inside the handheld app interface.

Utilizing the Ground Localization Feature

Using the localized correction feature within Emlid Flow serves as our alternative method to create a distinct, tailored coordinate system. To initiate and compute a local configuration grid, you will need a small network of known control points established in your local coordinate layout that can be physically occupied and captured in the field with an Emlid Reach receiver module.

Once occupied, you will pair the arbitrary local ground control values with the corresponding satellite coordinates tracked by your receiver. Emlid's field engineers recommend using a minimum of 3 or more paired benchmarks across your job site. Testing shows your relative Root Mean Square Error (RMSE) value will stabilize effectively without major variation shifts as you introduce more control points past this target minimum.

Once your field observations are tied to the local benchmark nodes, the program allows you to inspect the calculated linear parameters, scale factors, and residual tracking calculations before committing to the grid. Once applied, Emlid Flow provides the option to save this entire localization matrix as a reusable custom coordinate system profile for subsequent site visits.