Strange readings using Trimble S7 and MT1000

Hi guys

Just going though some data of points taken along the top of a retaining wall using Trimble S7 and MT1000.?ÿ I know the wall is level as I built it myself last summer. The total station was 21m away and the Hz angles were approx 84 degrees. I'm getting difference of 17mm between the elevation of points along the wall!

I checked the levels of the wall with a automatic level this morning and it is level with 4mm.

I know that there are known issues in vertical angle readings using the MT1000 in active mode (which is what I had it in) but should I really expect such big errors?

I'll repeat the setup soon and will take the readings again in Active, Semi-Active, and Passive mode to compare.

Cheers, Andrew

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