MassGIS/Datum

MassGIS and Datums

This page explains the Coordinate Reference System (CRS) used by MassGIS data, and how that relates to OpenStreetMap's standard CRS.

MassGIS data is in NAD83

MsssGIS data is natively in NAD83, which is the National Spatial Reference System of the United States. Some of the data is further specified to be in NAD83(2011), the most recent realization. Very likely, some of the data is in "NAD83(2011) epoch 2010.0", indicating that it is the NAD83(2011) position of a point on January 1, 2010. This level of detail accounts for the motion of tectonic plates, and is normally not a concern for OpenStreetMap.

Transforming

hard. proj does it wrong. Use ITRF2014.