Grid Coordinates in a Ground World

[jmshaw]

This might be a question, but is more likely a request/suggestion.

I believe that Carlson needs to improve/refine its handling of grid/ground translations. What the software really needs, to be an effective tool, is to offer options or switches that allow coordinates, inverses, and labels to be drawn or expressed as ground, grid, or both. Linework should have the option to be drawn as grid or ground, though I imagine ground would be the default. This goes for the entering of data too. For instance, if you are entering a deed or a plat into the system and it is correctly coordinated then you should be entering a grid coordinate and ground distances - i.e. you should not be getting precise ground distance by inversing the coordinates, which is the case with many plats. Another example would be that if you have 2,000.0000 feet of centerline to stake, the grid coordinates you upload into the collector should not be mathematically 2,000.0000 feet apart, but typically a small amount longer or shorter depending on your relation to the meridian and parallel lines.

Now I know you can set a scale factor. That is an incorrect application of grid-to-ground. While it works as a perfectly fine band-aid in most cases, the reality is that each and every unique geographic location has its own scale factor, albeit the change may be in the 0.00001 decimal. If my GPS collector can compute the proper State Plane or UTM coordinate for each location, applying a constantly changing scale factor, I certainly expect my full blown surveying/engineering suite to do the same.

This issue has been poorly understood by many and from my experience poorly addressed by most software offerings. This needs to change to better serve our future.

I see properly georeferenced data as critical in the future because GIS - more precisely high-accuracy GIS - will not be going away. I applaud Carlson for joining with ESRI and I cannot wait to see Carlson running on ArcView. To effectively work with the GIS, Carlson will need to address the issues I have stated. I think it is way past due that someone address this problem for AutoCAD, IntelliCADD, or MicroStation too.

What do you think? Comments and discussion are welcomed. I believe it is time to tackle this issue head-on and get the right solution as soon as possible.

[cujo]

I could not agree more. I definitely see a weakness in the software written for our industry, in this area.

It is definitely partly due to the fact that by large, the users of CAD for civil/survey use have little idea of the relationship of grid and ground coordinate systems. Your reminder of the "ground" we are losing to the GIS profession in this area hit home for me when I bought a great book on how to properly set up coordinate systems in GIS programs to work with all kinds of data.

The days of 10,000 10,000 local surveys are gone. It is a constant struggle in this day and age when we start with strong, accruate, grid coordinates (so cheap and easy to attain) and then have to struggle to work with ground distances in design or more prominently, cadastral records.

I would like to keep ALL my work on grid in CAD. To that end, I envision the capability to set toggles or settings and have Carlson make my ground to grid conversions on the fly for me...

While I'm on that subject, I like to reintroduce a dead horse I've beat to no avail; North Rotation. I loved Land Deskptop's ability to set a rotation (match a basis of bearing) and allow me to enter raw bearings from a map that would be taken into that rotated reference. Now I either have to make each rotation as I go or enter an entire map and rotate through CAD en masse.

When one of our geodetic programs, like TBC actually adds true CAD, I'm running away from plane CAD as fast as I can ... but that's going to be a while.