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Science & Alternative Science / Re: NASA’s Latest Moon Actors
« on: Today at 12:46:47 PM »Sometimes though the existing maps aren't accurate enough. Here's some details going into digging the cross-rail tunnels under London. Due to the small gap that the tunnels had to go through, between existing infrastructure and other tunnels, existing maps were found to only be accurate to 20cm per KM in a 3d space due to the curvature of the Earth. So a new co-ordinate system was produced.
https://learninglegacy.crossrail.co.uk/documents/building-a-spatial-infrastructure-for-crossrail/
https://www.engineeringsurveyor.com/software/1-026%20-%20Topographical%20Surveys%20and%20Mapping.pdf
The following link talks about how engineers and surveyors are attempting to display routes of long train infrastructure on a 2d plane on blueprints. You will probably be interested in figure 1 showing a simplified version of the ratio that has to be applied to convert from one to the other.
https://learninglegacy.hs2.org.uk/document/advances-in-engineering-survey-grid-transformations-for-rail-infrastructure/QuoteTo demonstrate the reasons for using the HS2 Snake Projection, imagine a line approximating the route from London to Birmingham. Measuring the line first in British National Grid, and then measuring again in HS2 Snake Projection would reveal an apparent increase in length of 60 metres. In fact, the length of the project on the ground did not change – it is just that the British National Grid is a best-fit for the whole country which means the map distortion is far in excess of what is appropriate for precision engineering required on projects like HS2.
You do realize that this is essentially the same thing as saying that "GPS proves the curvature" like ichoosenonsense claimed, right? It's all done on paper from a mathematical model of the ball Earth. In reality no one has measured the curvature. Ever.