Does anybody know how you would go about finding the exact elevation of your house? My little handheld Garmin eTrex told me I was at about 1700feet MSL, but that keep varying by like as much as 25-30 feet while just standing in my driveway. So I was wondering if there is a better way to know for sure what your exact or very close to exact elevation is?
I live at the top of a mountain in Jersey and I have 1 airport 5 miles away and another 9 miles away and ALWAYS have small aircraft traffic above my house, so I was going to look into getting a scanner so I can listen into what's going on. Both of the airports are UN-controlled though. In fact, I don't know for sure, but I might be able to get some other airports like 10 miles or more away since my house sits pretty high..
Just how precisely are you trying to measure? Depending on the age of a mortgage survey and the method used to make it, precision will vary. It will generally be better than a non-WAAS GPS receiver for elevation, but it won't be perfect.
That little GPS may be more accurate than you think. I have the eTrex Legend, and it can calculate the elevation barometrically. If there is an elevation that is known near you, then go there, calibrate the barometric altimeter, and return to your house. That should be pretty darned accurate. Otherwise, if you have a WAAS (Wide Angle Augmentation System) then the GPS calculated altitude is also pretty accurate. A difference of 20 feet isn't bad, all things considered. Why do you need such an accurate elevation??
I agree with Jordan. The survey you usually get for a residential closing is, frankly, what you pay for. If they were very carefully reseached and field verified, they would cost way more that $300. The elevation data is usually just enough to verify that you don't lie in a flood plain. I'm not knocking surveyors, it just the scope is limited for a house plat. If you got a full topographic survey for your property (approx $1,000/acre, your milage my vary) THEN you would have a reliable document.
Topographic maps, such as USGS Quad maps are probably not detailed enough for your property.
Stick with your gadget but hire a surveyor if you wallet is stronger than your curiousity.
BTW, I'm not a surveyor nor do I represent the Registered Land Surveyors Association. Just a free plug!
I'd still interpolate on a USGS topo of your section. Even if the elevation lines (iso somethings...i'm blanking) are 50 feet, you can get an idea. Also, lakes are usually precicely elevated, try to judge your elevation from them.