Correct interpretation of Origin column of CSV export

Emlid Flow & Emlid Flow 360 Coordinate Systems
1

I am using Emlid Flow 360 and Emlid Flow v12.1 on iOS.

I have set the local coordinate system for my project to EPSG:32615 with ellipsoid heights in Emlid Flow 360.

I see a mix of Local and Global entries in the “Origin” column of the exported CSV (via Emlid Flow v12.1). I just want to make sure I understand correctly that the value here simply indicates the coordinate system that was used when the coordinate was entered, because it clearly is showing both the Local (UTM) and Global (geodetic) coordinates.

  1. I have created a new project and set a local coordinate system as stated above.
  2. I then added a single point in Emlid Flow 360, specified in local coordinates.
  3. I’ve setup a base (RS2+) over an unknown point and obtained an approximate position with single average (5 seconds).
  4. I then used my rover (RS3) and went and surveyed the same point (not officially a stakeout).
  5. After exporting the project as CSV, I see the Flow 360 point with both UTM and geodetic coordinates and the origin listed as Local. The point surveyed with the RS3 shows both UTM and geodetic and the origin is listed as Global. (It also shows the base coordinates in both UTM and geodetic.)

Is the origin column simply documenting the CS that was used when the point was recorded? In my case, the surveyed point was recorded in global coordinates and converted to local upon export, while the Flow 360 point was entered in local and converted to global?

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3

Hi Brad,

You’re right! The Origin column in the CSV shows which coordinate system was used when the point was recorded. We keep the original coordinates exactly as they are, and then the system calculates the other pair of coordinates.

For the point you added in Emlid Flow 360, you entered it in local coordinates, and the system automatically calculated the corresponding global ones. When you surveyed the point with your RS3, it was recorded in global coordinates first, and then the system converted it to local in EPSG:32615.

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