Reproject.ReprojectPoints: what is the srcZtoMeter parameter?

May 11, 2013 at 5:59 AM
In the static method Reproject.ReprojectPoints, what does the srcZtoMeter parameter do?
May 13, 2013 at 6:52 PM
The srcZtoMeter and destZtoMeter parameters come into play when performing datum transforms. Datum transforms often require a Z value (in meters).
The srcZtoMeter parameter is a value that is multiplied by an input coordinate Z value to get it to meters prior to applying the datum transform.
Likewise, the reciprocal of destZtoMeter parameter is multiplied by the z value in meters to get it to the desired output coordinate Z. These parameters were added about 18 months ago. The datum transform code prior to that change assumed the Zs were in meters.
May 13, 2013 at 6:58 PM
Ah! A coefficient used to transform Z to and from meters. Thank you so much!