Just wondering if anyone knows of a cell phone program or maybe a website that computes SPC scale factors? Sometimes it would be nice to convert to ground distances on the fly....
Thanks in advance!
Thanks Loyal I appreciate it.
I know I'm being a wuss, but anything else available that allows you to enter in feet and with an ortho height in order to get a combiner factor?
Not that I'm aware of.
And REMEMBER, an "ortho height" would have to be converted to an ELLIPSOID Height to generate combined factor! So one would have to [also] access Geoid12a/b to get that done.
Loyal
I thought the elipsoid height generated the grid factor and the ortho height generated the elevation factor. Combined factor being an average if the two. I do have the current geoid model loaded into the gps to give me the ortho height.
Perhaps I don't have a complete grasp on the process. You can see why I'm in need of a program!
It's not hard to find material on using elevation and scale factors, but finding information on calculating either of them from scratch is not so easy. If you use "calculate elevation factor" and "calculate scale factor" as search terms on this site, you'll find some of the nuts and bolts of calculating them.
Scale factor is purely geometrical; no elevation is involved. It's purpose is to adjust the length of a line calculated from State Plane coordinates to the length of its corresponding line on the ellipsoid. Elevation factor uses a different geometrical construction along with ellipsoid height to adjust ellipsoid distances to ground distances. The combined factor is the product of the two, not their average.
ExpertGPS claims to be able to calculate scale factors and State Plane coordinates. I don't know if it's available for mobile devices.
In the JAVAD LS.... Hit inverse. Opposite the bearing, there is a button. Hit it. And it will toggle. GRID, MAG GEO, MAG GRID
Opposite the distance, there is a button. Hit it. And, it will toggle, SLANT, GEO, and GRID.
It's, shall we say, HANDY!
Jim_H, post: 365808, member: 11536 wrote: Combined factor being an average if the two.
Combined factor being the product of the two.
Jim_H, post: 365808, member: 11536 wrote: I thought the elipsoid height generated the grid factor and the ortho height generated the elevation factor. Combined factor being an average if the two. I do have the current geoid model loaded into the gps to give me the ortho height.
Perhaps I don't have a complete grasp on the process. You can see why I'm in need of a program!
"Combined factor being an average if the two."
Not to be rude, but as you said, you definately don't have a complete grasp on the process...
Thinking about it, that makes sense. Elipsoid height not ortho height for elevation factor because elipsoid is consistant, geoid is not.
I use a RTN leica system 1200 smartrover. I can convert lat/lon to SPC with a push of the button but I can't find anywhere what the CSF and convergence angle is at a givin point. Seems like that info built should be built in...
Jim_H, post: 365799, member: 11536 wrote: Just wondering if anyone knows of a cell phone program or maybe a website that computes SPC scale factors? Sometimes it would be nice to convert to ground distances on the fly....
Thanks in advance!
Carlson SurvCE has this option, I am pretty sure it is standard in all the data collection software, at this point.
Thanks for taking the time to reiterate that point Jim.... and thank you for not being rude. I would hate to see what that's like.