Johannes Gleim Mar 27, 2020:

origin In most cases the origin has the coordinates length x = 0, width y = 0 and elevation z = 0 per definition. This could be written as x,y,z = 0.0.0. The next elevated level in the context may be 100 or 100000 (unknown unit, may vary from nanometers to meters). I recommend to ask the client for confirmation. He only knows the application, the resolution of the 3D laser unit and the signification of 'level'. He should also know the kind of nameplate (marker?) and how to include a corresponding photo with such indications.

Daryo Mar 27, 2020:

if this site being surveyed is in Switzerland "niveau 100.000" would be a marker showing an altitude of "100 meters" with a precision of +/- 0.0005 meters.

The only fly in the ointment is that the lowest point in Switzerland is the surface of Lake Maggiore, at 193 m asl, so this "reference level" can not be the altitude above sea level. (unless they are surveying the bottom of the lake, rather unlikely ...)

My guess is that they have given an "altitude" of exactly 100 +/- 0.0005 meters to the starting / reference point to avoid having to use negative numbers for points below this "reference level/altitude".

Tony M Mar 26, 2020:

@ Thomas Leaving aside the question of FR-CH, it seems far more likely here to be 100 thousand, since the . is so rarely used in FR as a decimal point (though admittedly also pretty rare as a thousands separator!)
The key issue here is probably going to be the scale on which this device is working — if this if for land-surveying, for example, measuring in mm, 100,000 would equate to 100 m, which seems perfectly feasible for a distance marker to be defined... But I suppose, since this is an x-y-z system, it is also conceivable that this Niveau 100.000 could be the same point as the 'origin' — i.e. the origin is defined on the basis of some specific altitude, say 100 m asl etc.
I imagine Asker's wider document probably gives further clues, if only they can be gleaned. The fact that both points (if such is the case) appear to be able to be captured in the same photo somehow suggests they can't be very far apart; in this sense, a separation of 100 m sounds omplausible. This sounds a bit similar to the 'markers' used in e.g. photogrammetry.

Thomas Miles Mar 26, 2020:

FRs? Is the source document Swiss French (which has different conventions for punctuation)? Personally I would concentrate on working out whether "100.000" (presumably some kind of "reference level") refers to one hundred thousand or simply one hundred with three decimals.