https://www.ngs.noaa.gov/PUBS_LIB/NOAA_TR_NOS_NGS_0067.pdf
The paper describes how the IFVM will work. It will be like HTDP, but ultimately much better. Movements may be described by complex functions rather than linear displacements. Also, the new IFVM is anticipated to be 3D, whereas HTDP is only 2D.
I agree that HTDP velocities being hardwired in the program is problematic. We have HTDP built into our data collection software. The programming structure made it difficult to optimize HTDP performance.
I'm not certain. If the 50ppm zones or LDP (20ppm) zones are created, Grid north will be entirely different, I'm sure. If the default system is used, Grid North will likely be the same from SPCS83 (Note that for TXNC, the central meridian was moved and Grid north changed from SPCS27). If the default system is used then the zone boundaries will be the same, but the projection will be scaled to the average elevation of the zone area. I don't know if they will move the central meridian or not. Since our zones are all Lambert, I suspect they will not move the central meridian (sometimes in a Transverse Mercator, adjusting the central meridian can cause the projection surface to better approximate the topographic surface).
But even if they scale the existing projections to the average topographic surface, we'll still be dealing with linear distortions that cannot be ignored.
If the projection system parameters are the same it will be in about the same place. If different projection systems are devised it will be different. Astronomic north, on the other hand, will not change much regardless of NAD system, and not at all by different grid projection systems..
First, Texas appears to have more surveyors posting here than any other state - but then it's a big state.
Second, we likely will forget about magnetic north as it has become mostly irrelevant - it is still something we can discuss over adult beverages in past tense.
Third, for most of us, a new coordinate system should not be a problem. For those who work in global coordinates, or relative to state plane, it will require some constants to convert old coordinates. Each computation has the potential of error and we all rely on our manufacturers, or RTN to provide those solutions.
Rarely is there a problem but rarely does anyone check those solutions. Just reminds me many years ago sitting in a hotel room and trying to find a problem with some trig levels - turned out a trusted solution provider had a sign reversed in a calculation. Went unnoticed and only caught because of leapfrogging long baselines.
Finally, METADATA will be very important going forward when reusing old data.
GPS coordinates are the result of distances calculated by intersections based on timing from satellites and baseline observations.
Coordinates fall down on the list just above lot area calls which is last on the order of importance.
Nothing should ever replace the physical object on the ground. The coordinates derived from GPS observations are secondary to help the surveyor find the call. Once the call is found, it will supercede whatever number is associated with it.
It is no different than a surveyor calling one chain to a monument and we now measure it to be 67.5 feet.
Younger surveyors seem to think technology somehow overrules current methods. It doesn't. It is just another tool in the bag
I started in 1991 putting all my surveys on Grid North using sun shots. Now I do it with GPS but I only do a few boundary surveys per year. Most of my work now is construction.
All those surveys rotated with sun shots were just random coordinates but the bearings were good. The bearings in the central zone I am in changed about half a second between 27 and 83. I am just hoping they keep the grid bearings the same.