Hi all

whats are the Formulae for

1. reduction to ellipsoid correction

2. Line scale error coreection

using final stations heights to compute

Any help would be great

Cheers

Mat

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Hi Mat,

Is this what, you are looking for. I am confused on your  ?  But look over it

I have a lot of Data on this subject.

 This site has a lot of good info plus this. Go Thru Geodesy also.

Look under Corrections

http://aplitop.com/subidas/ayuda/en/MDT-Topografia/index.html#!reductionToEllipsoid

http://aplitop.com/subidas/ayuda/en/MDT-Topografia/index.html#!scaleFactorDueToHeight

Read this also

http://aplitop.com/subidas/ayuda/en/MDT-Topografia/index.html#!anamorphosis

 Here is some good reading.

http://www.esri.com/news/arcuser/0703/geoid1of3.html

Here from NOAA , I sent these 2 to Raymond Kinglsy on one of his Discussion.

But NOAA has a lot more on this subject at there site.

http://www.ngs.noaa.gov/GEOID/PRESENTATIONS/2007_02_24_CCPS/Roman_A...

Hi Mat,

Did I forget to tell you I added one on Geoid and MSL, there is also some more info on it.In the others. Thanks for the programs again i never seen these P to R or the R to P. I like it,very short, i like that. that is why i use mine so much. I will try them in some programs.

From PS reference handbook:

Orthometric correction:

Correction = −0.005288 sin2φ h Δφ arc1′

where: φ = Latitude at starting point h = Datum elevation in meters or feet at starting point Δφ = Change in latitude in minutes between the two points (+ in the direction of increasing latitude or towards the pole)

h ≈ H + N

where: h = Ellipsoid height N = Geiod undulation H = Orthometric height

hello.

you can find it at the end of your total station field user book.

at list at the leica´s field user book.

Exactly what are you correcting/adjusting? Anything I could say about formula would be redundant but the problem is somewhat different if you are computing surface distances/coordinates from a GPS survey than if you are transforming a tangent plane survey to grid (geodetic) coordinates.
According to Phil Stevenson of NGS, there is no direct connection between GPS coordinates & a tangent plane survey. Fortunately, there are some pretty good solutions to the problem. I am generally faced with the task of incorporating GPS control into a traditional theodolite survey. I usually work in heavily wooded areas with few good GPS sites. It is rare that I can survey anything with GPS alone. GPS coordinates are easy to deal with as they can be converted to Lat. or Long., grid or surface with simple conversion factors/ formulas. Incorporating tangent plane data can get a bit sticky. I believe most DOTs make adjustments at regular intervals over long distances.

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