Coordinate sytems & datums

Operating a Reach RS2 with ReachView 3.

When creating a new survey in ReachView 3 to collect points as a rover via NTRIP, I’m able to specify a coordinate system and vertical datum. The app provides the note to be sure that the base or NTRIP is using this same datum. However, it seems that I am unable to specify a coordinate system or vertical datum when operating in base mode.

If I am interpreting this correctly, the height that is input/measured in base mode is the ellipsoidal height. I’m assuming that when this ellipsoidal height is sent out via NTRIP the rover receives these corrections and recognizes that it is the ellipsoidal height. The rover then transforms/converts the lat, long, and height to the coordinate system and vertical datum that the rover is using.

Does this seem correct?

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It seems at least in the ballpark. Need to make sure you have the geodetic coordinate for the point that your base is on. That could be WGS84 or NAD83 which is different than a State Plane NAD83. Putting the geoid in the project allows it to convert from geodetic to orthometric.

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https://docs.emlid.com/reachrs2/reachview-3/countries/usa#base-setup

Hi Tyler,

The rover expects the base will transmit its position in a geographic coordinate system that is based on the same datum as the coordinate system of the rover. Indeed, you cannot choose on which coordinate system the base transmits corrections.

That’s why you may see a note in our app when you select the coordinate system. It reminds you to check that the base coordinate system or NTRIP corresponds to the one you set on the rover.

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