I work for a wastewater utility in Nebraska, USA, and we are beginning to try to visualize our sewer network data in three dimensions. Our sewer data has historically been projected in the NAD 1983 StatePlane Nebraska FIPS 2600 (US Feet) horizontal coordinate system (WKID: 26852), and while we have used the NAVD88 height (m) vertical coordinate system (WKID: 5703) to store elevation information for this data, we have historically recorded our elevation data in the attribute table rather than updating z-values in the geometry.  As we have been exploring different ways to visualize the sewer data in three dimensions, we have encountered issues publishing web scenes due to the difference in units between our horizontal and vertical coordinate systems. As a result, we would like to reproject the data into a different vertical coordinate system which uses the same datum as our horizontal coordinate system and records z-values in US Feet.  Because our sewer data is used by several local entities to support construction and maintenance projects, we are hesitant to reproject our data unless we are sure that doing so will not compromise horizontal accuracy. Within ArcGIS Pro (Version 3.3.0), the horizontal and vertical coordinate systems appear to function as separate entities, where changing one does not affect values stored in the other. Does this appearance reflect what is actually occurring during projection, or might changing our vertical coordinate system impact values stored in our horizontal coordinate system? ... View more

Hi, I would like to know if there is a difference between NAD_1983_CSRS_MTM_9 and NAD83(CSRS) / MTM zone 9 coordinate systems in ArcMap 10.6. Here are the characteristics for NAD_1983_CSRS_MTM_9: Projected Coordinate System: NAD_1983_CSRS_MTM_9 Projection: Transverse_Mercator False_Easting: 304800.00000000 False_Northing: 0.00000000 Central_Meridian: -76.50000000 Scale_Factor: 0.99990000 Latitude_Of_Origin: 0.00000000 Linear Unit: Meter Geographic Coordinate System: GCS_North_American_1983_CSRS Datum: D_North_American_1983_CSRS Prime Meridian: Greenwich Angular Unit: Degree   Here are the characteristics for NAD83(CSRS) / MTM zone 9 : Projected Coordinate System: NAD83(CSRS) / MTM zone 9 Projection: Transverse_Mercator false_easting: 304800.00000000 false_northing: 0.00000000 central_meridian: -76.50000000 scale_factor: 0.99990000 latitude_of_origin: 0.00000000 Linear Unit: Meter Geographic Coordinate System: NAD83(CSRS) Datum: NAD83_Canadian_Spatial_Reference_System Prime Meridian: Greenwich Angular Unit: degree   The layer of my project in ArcMap is in NAD_1983_CSRS_MTM_9, but I noticed the shapefiles I exported from Pix4Dmapper are in NAD83(CSRS) / MTM zone 9 when I import them in ArcMap. It seems to me like it is the same coordinate system, therefore I don't understand why there are two ways to "write" it in ArcMap. Is there a real difference (I notice the Datum is not written the same either)?   Thank you for the info! ... View more