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DTM examples request (part 2)


mmyoung

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Yes ? I suppose I could dial this in a little better by saying we generate fairly fine grained, hand-surveyed or GPS information, in which we like to get resolution under a meter where it's necessary (or possible) for storm water control. We'd like to take this as a point cloud into an interpolated surface.

Does Landmark do this sort of thing? Say, from an Excel spreadsheet?

A couple rendering attached to show you approx. the level of detail we're trying for.

thanks again ?Michael

Edited by mmyoung
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Yes ? I suppose I could dial this in a little better by saying we generate fairly fine grained, hand-surveyed or GPS information, in which we like to get resolution under a meter where it's necessary (or possible) for storm water control. We'd like to take this as a point cloud into an interpolated surface.

Fair enough ? but the DTM engine works just the same way regardless of grain or input method. The whole idea of the DTM is that you get an interpolated, triangulated (TIN) surface.

GPS? I don't think so, at least without middleware.

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Landmark has a number of options for importing survey data. For data generated by survey grade GPS units the data has to be converted to UTM. I know on the Leica GPS that I usually rent their is an export on the menu that will allow me to export to a CSV file that VW can import.

If you are using handheld gps you may need some middle ware but... you may not get the degree of accuracy you will need from the GPS unit. At any rate the lat and log from the GPS will have to be converted to UTM and you will need a file with the data.

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As far as I know, VW can convert long/lat coordinates to Cartesian coordinates only when importing ArcView (=Shape) files.

Furthermore, AFAIK, these conversions are not necessarily universal: many countries have one or more specific Cartesian coordinate systems and zones. Should I go and buy coal to fire up my last working G4 Mac with an ancient MapInfo in it, I could ascertain this: when exporting to a Cartesian coordinate system, there are tens of options.

Our friend Professor Trimble from the Dominican Republic has made it quite clear that VW cannot utilise GPS data. I have no reason not to believe him.

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