system odniesienia

14:13 Mar 8, 2014 

Personally I find the very term "datum" pretty awkward, but since it's in the surveyors' jargon we need to respect it. Still, I like your rendition very much [the orientation of the control grid reference system]. I hope the Asker is reading this. Thanks for talking. Later M

13:59 Mar 8, 2014 

Very informative. Let me observe that "reference system" is but two words of a longer phrase: orientacja systemu odniesienia sieci kontrolnej (w geodezji). the orientation of the control grid reference system. But I am keeping an open mind.

13:17 Mar 8, 2014 

You are right I suppose
"orientation of the datum" yields some web hits though
https://www.google.pl/?gfe_rd=ctrl&ei=ARgbU9b3IYiX_Abx94GwAg...

13:06 Mar 8, 2014 

From the definition kindly provided by mike23, it would appear that "datum" is a set of "reference points." Here, we are talking about something that can have "orientation" with respect to a control grid. Reference points does not seem to fit, in my humble view.

09:57 Mar 8, 2014 

I had the same dilemma and the person for whom I was working - a surveyor - opted for "reference system", arguing that "datum" would have been understood as a single point of reference, whereas "system" implies a grid of points. Perhaps he was mistaken, perhaps “datum” is OK, but it made sense to me.

21:01 Mar 7, 2014 

Datum - A point, line, or surface used as a reference, as in surveying, mapping, or geology
http://www.thefreedictionary.com/datum

A geodetic datum (plural datums, not data) is a reference from which measurements are made. In surveying and geodesy, a datum is a set of reference points on the Earth's surface against which position measurements are made and (often) an associated model of the shape of the Earth (reference ellipsoid) to define a geodetic coordinate system. Horizontal datums are used for describing a point on the Earth's surface, in latitude and longitude or another coordinate system. Vertical datums measure elevations or depths. In engineering and drafting, a datum is a reference point, surface, or axis on an object against which measurements are made.
http://en.wikipedia.org/wiki/Geodetic_datum