Level Heads

[gregcashen]

Anybody know of a reliable method to change the level heads to show NGVD elevations. I created a custom level head with a text field that says NGVD and shows the elevation in +12.0' notation, but it only works on one side...i.e. it doesn't mirror properly. The text flips to the other side of the level head, or it mirrors about the level line...

Thanks,
Greg

[sbrown]

If you want it on the other side you have to check the box on that side, if you just drage your head it will flip wrong. click on the level line and check the box.

[gregcashen]

I am checking the box.

[christopher.zoog51272]

I am checking the box.

post your file freebie, and we'll take a look at it :)

[Steve_Stafford]

I've seen this behavior too, in the the Level Head family when I attempted to add "ELEV:" in front of the value...

[gregcashen]

Here it is...

BTW, I would also like for it to have a "+" or "-" beside the value based on elevation relative to NGVD...any ideas?

Thanks,
Greg Cashen

[Dean Camlin]

All right, I'll bite: what does NGVD mean? :roll: New Grade Value Drop? Nearly Great Vehicle Design? No Good Volume Damper?

[gregcashen]

National Geodetic Vertical Datum of 1929

What is NGVD 29?
"The National Geodetic Vertical Datum of 1929: The name, after May 10, 1973, of (the) Sea Level Datum of 1929." (Geodetic Glossary, pp. 57)

"Sea Level Datum of 1929: A vertical control datum established for vertical control in the United States by the general adjustment of 1929."

"Mean sea level was held fixed at the sites of 26 tide gauges, 21 in the U.S.A. and 5 in Canada. The datum is defined by the observed heights of mean sea level at the 26 tide gauges and by the set of elevations of all bench marks resulting from the adjustment. A total of 106,724 km of leveling was involved, constituting 246 closed circuits and 25 circuits at sea level."

"The datum (was) not mean sea level, the geoid, or any other equipotential surface. Therefore it was renamed, in 1973, the National Geodetic Vertical Datum on 1929." (Geodetic Glossary, pp. 56)

...ask and ye shall be answered!

Most of the projects we do here are in the 100-year flood plain...we use NGVD to establish flood clearance heights.

Greg Cashen

[JTF]

Had the same problem when I first downloaded 5.1.
Checking the opposite box did not work right.

I had created a left and right level head with text on left and text on the right of the level head and it worked good.

Then one day, not sure how the level head worked by checking the other side as it should work.

Strange but true.

[Dean Camlin]

What is NGVD 29?
"The National Geodetic Vertical Datum of 1929: The name, after May 10, 1973, of (the) Sea Level Datum of 1929." (Geodetic Glossary, pp. 57)

"Sea Level Datum of 1929: A vertical control datum established for vertical control in the United States by the general adjustment of 1929."

"Mean sea level was held fixed at the sites of 26 tide gauges, 21 in the U.S.A. and 5 in Canada. The datum is defined by the observed heights of mean sea level at the 26 tide gauges and by the set of elevations of all bench marks resulting from the adjustment. A total of 106,724 km of leveling was involved, constituting 246 closed circuits and 25 circuits at sea level."

"The datum (was) not mean sea level, the geoid, or any other equipotential surface. Therefore it was renamed, in 1973, the National Geodetic Vertical Datum on 1929." (Geodetic Glossary, pp. 56)

Thanks, Greg. I'd never heard of that. I hope my surveyors have.