Trig Level Elevation Transfer – Refraction? Reciprocals?
If you were tasked with a trig level transfer of elevation from a benchmark at ground level, up to the 7th floor of a hotel, under construction (windows not installed) – would you want to shoot it both ways? Meaning shoot up to a prism on the 7th floor and then set up on the 7th floor and shoot back down to the benchmark? I’m wondering if refraction due to different temp gradients would be an issue in such a scenario, making it wise to get reciprocal measurements and average. Would it be an issue? Or am I reading too many geodesy books?
Working for an engineer who didn’t want to more than double the time, or carry the gear up 7 flights of scaffolding. (Yes it’s already done, from the ground only, but I wanted to shoot back down to compare)
It’s about a 30m height difference – set up about 50m away from building – can see benchmark from 7th floor – stairwell and lift shaft not available for alternative solution. Everything shot on 2 faces. Building is pre-made panels so we are just checking/confirming what the elevation should be, that any creeping gain or loss over the 7 story’s is acceptable.
So yes, it’s mainly refraction I was worried about. Yes, No?
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