SPCS2022

Shawn Billings

Shawn Billings

Shawn Billings
5PLS
In the United States, a new reference frame is on the horizon. TRF 2022 and NAPG 2022 will replace the current NAD83 and NAVD. As part of this all States will have a new State Plane Coordinate System: SPCS2022. NGS has set for its policy and procedures for how the zones will be created. There are currently three options for the States to chose from:

1. Use existing zones with the zone scale factor modified to the approximate topographic surface. For small States with little topographic variation, this will probably be suitable. This is the default that NGS will apply without any input from the stakeholders within a State
2. NGS will design coordinate systems that have 50ppm linear distortion (maximum 400ppm). As I understand it, 90% of the population, 75% of municipalities and 50% of the zone area will be <+/-50ppm linear distortion (0.05 per 1000).
3. Stakeholders within a State can decide to design Low Distortion Projection (<+/-20ppm) Zones for the State.

Stakeholders are defined as:
  • State departments of transportation
  • State GIS or cartographer offices
  • State professional surveying and engineering societies
  • State GIS or other professional geospatial organizations
  • Universities or other post-secondary educational institutions within a state that perform geospatial education or research.
  • Other departments, offices, and organizations within a state with roles and functions similar to those of the organizations listed above
This is a great opportunity for State societies to make a significant impact on an issue that surveyors face everyday: Grid vs. Ground. Choosing designs that minimize the issues of linear distortion could be a tremendous benefit to surveyors and design professionals for generations. Deadlines are approaching, so I would recommend getting involved now within your societies to see if you can make a positive difference for your State.

SPCS2022 Policy and Procedures:

2022 Policy Changes - State Plane Coordinate Systems (SPCS) - Tools - National Geodetic Survey

www.ngs.noaa.gov www.ngs.noaa.gov

Recent NGS Webinar update on the development of SPCS2022 (April 11, 2019)

State Plane Coordinate System Update | Webinar Series | National Geodetic Survey

www.ngs.noaa.gov
 
Steve Douty

Steve Douty

Well-Known Member
It is also a great oppertunity for surveyors (and JAVAD users) to improve the adjustment and therefor the results of 2022 observations in their area by submitting "GPS on Benchmark" observations. I think it would be a real feather in our cap for JAVAD users to have a positive impact on the new system(s).

It would also be helpful to me to have a complete set of instructions on how to setr up the JAVAD action profile for this type of observation and additional instructions on how to download the data from both the base and rover in a manner that works for NGS.

p.s. Adam sent me some of these thoughts about a year ago.
 
Shawn Billings

Shawn Billings

Shawn Billings
5PLS
Steve Douty said:
It is also a great oppertunity for surveyors (and JAVAD users) to improve the adjustment and therefor the results of 2022 observations in their area by submitting "GPS on Benchmark" observations.
Click to expand...

This is partially true. I suspect that the GPS on Benchmark observations will help with possible future transformation software for transforming from NAVD88 to NAPG2022, but the NAPG2022 model is actually going to completely break away from using GPS on benchmarks for its development. As I understand it, NAPG2022 is going to be completely based on gravimetric observations rather than using hybrid approaches using gravimetric observations and GPS observations on benchmarks established by leveling. Level loops have issues due to observational errors, but also have issues related to dynamic heights and orthometric heights. Dynamic heights are as measured by a level. The differential heights of two points will vary depending on the route taken because the pull of gravity varies along the routes taken. Differences in orthometric heights are the subtracted difference between two orthometric heights and will not change as there is no route that figures in to the difference. The new NAPG will be based only on gravity models and will not be influenced by the dynamic heights from level runs.

I suspect the GPS on Benchmarks will help develop software that will link the new model (with no dynamic heights) to the old models (with dynamic heights), but the new model itself will not be based on leveled benchmarks.

I'm not a geodesist and barely have a grappling on all of that, but that's the best I understand at the moment regarding heights.
 
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