Scale Factor
The DAF isn't applied to any distances. Control is run with GPS and leveling. Once finished state coordinates are calculated then globally the coordinates are multiplied by the DAF and Surface coordinates are produced. From there all work is done using those numbers. The ariel and scan mapping, property surveys, design engineering, construction, and final surveys are done using the Surface Coordinates. No distances are manipulated, simple inverses produce the surface distances.
Math Teacher, you're in North Carolina are you?
How are you doing there, we spent a decade almost having NC as a second home.
It's heartbreaking watching the news.
It's as bad as it gets, Moe. I'm a hundred miles or so from the mountains and got only moderately heavy rain and wind, but a lot of my favorite fall destinations are destroyed.
Those beautiful roads that followed creeks became high volume and high velocity sluices. Just destroyed everything within their reach.
Folks here have bought all the bottled water available and anything else on needs lists and sent it to distribution points as near the disaster as possible.Aside from Asheville and Boone, that's a really impoverished area of our state and peop;e are far worse off than we can imagine.
I sent a good-sized check to the Western NC chapter of the Red Cross and a bigger one to a church in the area. If anybody here can spare a dime, it will do a lot of good and be greatly appreciated.
Thanks for your concern, Moe. This is a great community and I'm privileged to be allowed to participate here.
I would argue that the DAF is applied to distances. When you inverse, between two ground coordinates, you are using grid coordinates adjusted by the DAF to calculate a distance.
Inversing between two coordinates that have been divided by a combined factor and inversing between two grid coordinates and then dividing by a combined factor are mathematical equivalents. That's why, save for the mistaking one for the other argument, creating ground coordinates from grid coordinates is perfectly acceptable.
It's an easy process to verify. Just inverse between two grid coordinates and divide the result by a combined factor. Then take the same two grid coordinates, divide each by the same combined factor you used before, and then calculate the inverse between the adjusted coordinates.
Did you get the same answer in both calculations?
Still using my old Defense Mapping Federal Credit Union account. Okay, the name has changed but not the account number.
Fond memories of the good old HTC.
It's terrible, hopefully they can make some headway getting supplies into the really bad areas. To think Asheville is in a hurricane zone isn't something that would have crossed my mind.
No, you will not get the same answer using a combined scale factor between two points and using the Datum Adjustment Factor, they will never be the same number.
You have to use the same factor in both calculations.
Then you will get the same answers of course, you would multiply a number by the DAF then divide it, so it's identical. But the DAF and the CSF are two different numbers.
Yes, but the theory is the same. Isn't the DAF derived from the combined factor?
How can you say that the DAF is a more accurate adjustment than the combined factor?
