Friday's Dumb Question

I haven't tried to repeat the calculations, but it looks at first glance like you put in feet when the button was selected for meters input.

Bill93, post: 331901, member: 87 wrote: I haven't tried to repeat the calculations, but it looks at first glance like you put in feet when the button was selected for meters input.

You have no choice in the matter. NAD83 is meters, NAD27 is feet.
I could have just screwed up the numbers when I first input them into my survey. I'm looking for the NGS, or Vermont SPC converter I first used to "go the other way".

When you get coordinates on other side ofcworld, nost likely caused when you enter the Longitudinal wrong. It must have a minus sign, for West. Otherwise it assumes East Longitudinal.

Try meterss. Also check the Zone ID for Vermont.

If the program wants meters, then convert your feet numbers to meters before entering.

I don't know if you have survey feet or international feet, which will make a few feet difference in the coordinate values (what did you use to get the original coordinates?), but if you divide the given coordinates by the conversion factor to meters before entering, you will get reasonable lat lon values. Using survey feet should get around 43 40 30.54200 72 34 56.97999 which is a hundred yards SE of your driveway and 25 yards SW of the middle of the highway.

The general convention, as I understand it, is that State Plane Coordinates for NAD'83 is expressed in Meters, and for NAD'27 is feet.

Bill93, post: 331931, member: 87 wrote: If the program wants meters, then convert your feet numbers to meters before entering.

I don't know if you have survey feet or international feet, which will make a few feet difference in the coordinate values (what did you use to get the original coordinates?), but if you divide the given coordinates by the conversion factor to meters before entering, you will get reasonable lat lon values. Using survey feet should get around 43 40 30.54200 72 34 56.97999 which is a hundred yards SE of your driveway and 25 yards SW of the middle of the highway.

I think you're onto it! I'm still looking for the other converter--it might have been on VT's web site, but I bet you're right...I got these numbers, entered them in my CRS dialog box; translated the survey to those coordinates, never thinking they were meters. My survey's in survey feet.

I'll make the adjustment. Thanks!

rfc, post: 331938, member: 8882 wrote: I think you're onto it! I'm still looking for the other converter--it might have been on VT's web site, but I bet you're right...I got these numbers, entered them in my CRS dialog box; translated the survey to those coordinates, never thinking they were meters. My survey's in survey feet.

I'll make the adjustment. Thanks!

Lat Long puts me near highway 12 back East. I would suggest that you drop the - sign, Google knows what W is.

Bill93, post: 331931, member: 87 wrote: If the program wants meters, then convert your feet numbers to meters before entering.

I don't know if you have survey feet or international feet, which will make a few feet difference in the coordinate values (what did you use to get the original coordinates?), but if you divide the given coordinates by the conversion factor to meters before entering, you will get reasonable lat lon values. Using survey feet should get around 43 40 30.54200 72 34 56.97999 which is a hundred yards SE of your driveway and 25 yards SW of the middle of the highway.

So, if one's survey is on State Plane Coordinates, using NAD83, which is metric, does that mean that all the field and office work now happens in meters? Is this a function of settings in the DC? Office software?
Can I pick my one point in SPC, which is in NAD83 metric Northing and Easting, convert those two numbers to Survey Feet, and then translate my entire survey, and just keep everything in feet?

U.S. survey feet x 1200/3937 = meters.

This is not the same as 2.54 cm = 1 inch !!!

It makes a significant difference when converting SPC coordinates.

Dave Karoly, post: 332007, member: 94 wrote: U.S. survey feet x 1200/3937 = meters.

This is not the same as 2.54 cm = 1 inch !!!

It makes a significant difference when converting SPC coordinates.

So, is that a "yes", lol?

All my measurements have been in feet (total station only). I guess the question I'm asking is: will the software do the math, but show all the coordinates in meters (and include the appropriate scale factors of course). Once I have one known good NAD83 coordinate, do I even need to worry about this?

Keep the project in an assumed datum with units in us feet. If you don't have GPS or NGS monuments nearby, then you can not get to SPC. You are just fooling yourself and others by using fake SPC. We have to decipher through crap surveys like this all the time. It is a real pita.

You are trying to put way too many eggs in one basket. Just focus on your measurements, angle distances. No need for a residential topographic survey by a novice to be on SPC. Forget about scale factors, latitude, longitude, and meters.

leegreen, post: 332020, member: 2332 wrote: Keep the project in an assumed datum with units in us feet. If you don't have GPS or NGS monuments nearby, then you can not get to SPC. You are just fooling yourself and others by using fake SPC. We have to decipher through crap surveys like this all the time. It is a real pita.

You are trying to put way too many eggs in one basket. Just focus on your measurements, angle distances. No need for a residential topographic survey by a novice to be on SPC. Forget about scale factors, latitude, longitude, and meters.

Great advice, Lee, but i want to learn how to do it.
I'm getting warmer though...Cayuga Lake:-D
I found the NGS site where I originally converted Lat/Long to SPC. It was here:
http://www.ngs.noaa.gov/TOOLS/spc.shtml

But when I moved everything, I ended up near Cayuga Lake. If nothing else, I'm getting in some armchair traveling around the north east.
I'll keep hammering away at it.

If you must, then I suggest you use Google Earth.

In settings you can configure the datum and units.

Also Magnet can convert Lat/Lon to SPC. Plus you can load Bing background map for check.

This is what I come up with from your data.

Geographic Coordinates
N43å¡40'30.54"
W72å¡'34'56.98"

Cartesian Coordinates
Northing 130551.282m
Easting 493347.678m

Northing 428317.00UsFt
Easting 1618591.51UsFt

leegreen, post: 332023, member: 2332 wrote: This is what I come up with from your data.

Geographic Coordinates
N43å¡40'30.54"
W72å¡'34'56.98"

Cartesian Coordinates
Northing 130551.282m
Easting 493347.678m

Northing 428317.00UsFt
Easting 1618591.51UsFt

Lee:
That's the place. Is it as simple as taking the Coordinates in metric, converting them to feet, and using those numbers in the survey, thereafter keeping everything in feet? I'm seeing the error of my ways. I entered the coordinates in metric, expecting my software (TPC) to do everything.

I may well have to try this all in Magnet.:-)

Yes. That's right.

UsFt divided by 3.2808333333 = Meters

Or
Meters X 3.280833333 = UsFt

Keep your survey in USfeet.

That worked perfectly!
Thanks, Lee.

rfc, post: 332031, member: 8882 wrote: That worked perfectly!
Thanks, Lee.

I may be repeating someone but....
Every single person on here started from scratch. Our curiosity was a big part of moving forward. Don't ever be shy about asking qusetions. Occasionally you will get a rude response from someone who forgot where they started. Let it roll off and keep asking. When they come to you hoping for a job you can see if thier attitude has improved.
Good luck, Tom