Community Forums

NGS map of geoid ch...
 
Share:

NGS map of geoid changes  


Bill93
Posts: 5524
Member
(@bill93)
5,000+ posts
Joined: 9 years ago
5 Replies
MightyMoe
Posts: 6109
Member
(@mightymoe)
5,000+ posts
Joined: 9 years ago

Interesting map.

The preliminary heads-up is that our area will see a drop in the ortho elevations of 2'.

This will place the new elevations close to the NVGD 29 numbers.

To get to that number with the small Geoid shift will mean that the ellipsoid heights will also be lowered substantially.

2' of course being about 60cm

 

Reply
3 Replies
RichardLHardison
Member
(@richardlhardison)
Joined: 8 months ago

5+ posts
Posts: 14

In my region (Mountains of NC), NAVD 88 elevations were lower than NGVD 29 by about .3 to .4 feet. From the map, we're going to be even lower.

Reply
Steven Metelski
Member
(@steven-metelsky)
Joined: 1 year ago

100+ posts
Posts: 163

When does this go into effect or is this just a test bridge to the next datum?

Reply
Bill93
Member
(@bill93)
Joined: 9 years ago

5,000+ posts
Posts: 5524

As I think I understand it, Geoid18 will be released in mid-2019 (it's only a beta yet).  It won't change the NAVD88 elevation on any NGS data sheets, but will be a (we hope) more accurate model for  converting from ellipsoidal height in GPS sessions at locations between benchmarks.

Reply
MightyMoe
Posts: 6109
Member
(@mightymoe)
5,000+ posts
Joined: 9 years ago

EDIT: NGVD29

Reply