CS usage in RV3

Emlid Flow & Emlid Flow 360
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I’m using NAD83(CSRS)v7 in reachview 3. It is a time dependent coordinate system tied to ITRF14. Am I right in assuming that the time dependency is included in the reach3 transformation, and the coordinates recorded by reachview3 are the same epoch as the observation date?

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Hi Derek,

I’ll check it with the team and write back.

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Hi Derek,

If I get it right that you would like to get end results in NAD83(CSRS)v7 LLH, you will need to enter the base position in NAD83(CSRS)v7 LLH. In this case, you will get the correct coordinates with no issues. If you plan to use any other coordinate systems for the base or rover, please elaborate on it.

Please note that the ReachView 3 app doesn’t support transformations at the moment. The rover unit provides coordinates using the datum set on the base. We apply only projection on our side if needed.

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Thanks for the reply. I understand that i need to input base coordinates in my desired coordinate system in order to obtain cm-accurate rover positions. This is generally what I would be doing, so that is all good. My question is more theoretical, about what happens in single mode, and coordinate system is set to NAD83(CSRS)v7. This question becomes relevant in certain circumstances, e.g., if you were to set up your base using single solution averaging. The RS2 receives position data from satellites in WGS84 coordinate system. When not receiving corrections from a base, and reachview is displaying in NAD83(CSRS)v7, to my understanding there are three possibilities for what is happening: 1) reachview is not transforming at all from WGS84 to NAD83(CSRS)v7, (not great), 2) reachview is transforming using a static transformation valid for specific epochs in the past, eg 1997 or 2010, (better), or 3) reachview is using a time dependent transformation that is valid for the date of observation (best). Any info regarding exactly what the software does would help me to understand things better. From your answer I suspect answer 1) is correct, but I would appreciate clarification.

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Hi Derek,

You are right. If the receiver works in Single, ReachView 3 doesn’t transform WGS84 to another datum. However, in most cases, the difference between datums lies within the coordinates’ precision in Single. So, you will still get a few meters of precision.

1 Like
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Thanks for the information. Ive been impressed with the careful and precise support provided on this forum, keep it up!

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