Coordinates – NAD and WGS

Coordinates are a central part of the C-Master system. The 32-bit version handles NAD27 (the old system), NAD83, and WGS84 datums. You have a range of options available for the entry and display of coordinates and datums.

Even though multiple datums are supported, please be aware that C-Master is not a GIS program, and coordinate integrity and accuracy is subject to multiple factors. Coordinates are stored internally in UTM coordinates and are accurate to about 1 meter. Coordinate transformations to Lat/Lon are displayed to 6 decimal places and are generally accurate to less than 1 foot. State plane coordinates are assumed to be specified in US Survey Feet (NAD27). An option exists for International Feet for NAD83 coordinates. Meters are not allowed for State Plane Coordinates although the NADCON conversion software allows it.

NAD27 is the default datum for C-Master. This maintains compatibility of the old log data with the new system. You can choose to make a different datum the default through the Configuration File. For example, you can have log strips displayed in NAD27 and Master Catalog listings in NAD83 with Catalog Search results files in WGS84. All KML coordinates supplied for use by Google Earth are in WGS84.

All the options are covered in the User’s Manual..

Coordinate conversions are performed using datum shift files (for NADxx datums). The datum shift files supplied with C-Master are publicly available from the US Government, the Canadian Government, and other countries. Generally NAD83 and WGS84 coordinates are nearly the same, while the NAD27 coordinates are significantly shifted. If you are working in Alaska, of Offshore Louisiana, there are no datum shift files for some of these areas. For these areas, it is recommended that you use WGS84 or NAD83 exclusively.

Specifying NAD27 coordinates outside of the Continental US will assume that the coordinate is a Clark 1866 spheroid projection, while NAD83 coordinates outside of the Continental US will assume the coordinate is WGS84.