CountryPlans Forum

General => General Forum => Topic started by: RonDay on September 03, 2007, 09:25:44 AM

Title: Measuring Elevations
Post by: RonDay on September 03, 2007, 09:25:44 AM
Is there a a fairly easy/inexpensive way to measure differences in ground level/elevation over an area where it's impractical to use a transit level (optical or laser) and stick? This isn't for building layout as much as general information about the lay of the property.

Our 10 acres is a right triangle with the long side 1500 long. We're not looking for extremely high resolution, but I don't think standard GPS is accurate enough, either. Am I expecting too much?

TIA,
Ron
Title: Re: Measuring Elevations
Post by: glenn-k on September 03, 2007, 11:31:20 AM
I used a topo map of my property to get my elevations.  Pretty accurate and available online.

http://mapper.acme.com/
Title: Re: Measuring Elevations
Post by: MountainDon on September 03, 2007, 09:48:05 PM
Standard GPS are not accurate enough for elevation work. Some though have an electronic barometer built in. They need to be calibrated, something that can be time consuming.

Topo map info is usually accurate enough. The National Geographic program TOPO! will allow reading by passing the cursor over the interested point. Maps cost $1C per state.
Title: Re: Measuring Elevations
Post by: firefox on September 03, 2007, 09:57:02 PM
Thanks for the tip on the mapper Glenn, Seems to be
pretty accurate considering the land is somewhat remote. Eureka, Nevada.
Bruce
Title: Re: Measuring Elevations
Post by: glenn-k on September 03, 2007, 10:58:50 PM
My pleasure.  I use it locating mines also.  Playing.  Very helpful. :)
Title: Re: Measuring Elevations
Post by: RonDay on September 04, 2007, 10:10:12 AM
QuoteI used a topo map of my property to get my elevations.  Pretty accurate and available online.

http://mapper.acme.com/

Glenn,

I keep getting an "error on page" message when I click on or copy and paste the URL. However I'm not sure either this or TOPO will give us what we want, which is to be able go to a spot on our 10+ acres and be able to tell that it's "X" feet and inches (say within 3 to 6 inches) above or below a reference point we've established. It would be nice to be able to ID all of this on a map, but it's not critical.

I guess the easiest way to get what we want is to guesstimate the high point (Point A) on the property and mark it with a stake, then use the transit level and 8 ft. stick we have to establish relative elevation at other spots visible from Point A. We should then be able to take relative measurements from spots not directly visble from Point A, but that are visible from a point qalready referenced from A. We'll end up with a series of spots that all refer back to Point A. It'll be time consuming and I'm sure there'll be some slight errors, but we won't be doing it all at once.

Does this make sense? Is there an easier way to do it without spending at least several hundred, if not more, on one of the new laser set ups?



Title: Re: Measuring Elevations
Post by: Sassy on September 04, 2007, 11:33:20 AM
there are people who measure elevations for fields on farms - using lasers - to level them.  so there's got to be a way.
Title: Re: Measuring Elevations
Post by: tc-vt on September 04, 2007, 09:28:23 PM
A water level is clumsy, but accurate and cheap.  It can go around corners.  You're only limited by the length of the hose and your height, ie. measuring elevation differences no greater than that which you can be able to see the water height in the hose.  There are fancy water levels for one person use that beep when the water is in a certain range.

http://www.zircon.com/sellpages/LevelAndLaser/WL25/WL25.html

http://www.zircon.com/sellpages/LevelAndLaser/WL25/Photos/WL25-pix.html

http://edo1.vci.net/waterlevel/

Tom
Title: Re: Measuring Elevations
Post by: MountainDon on September 04, 2007, 09:58:41 PM
A topo map won't be of any help if you're looking for 3 to 6 inch accuracy. Ditto the GPS. A top of the line barometric GPS might come to within 5 - 10 feet at the very best. The topo map; well not even in the ballpark.

A water level is quite good within it's limitations. One of those limits is hose length and speed of water level change. The longer the hoe, the more friction between the liquid and the hose walls. More friction = slower response time. I've never used a hose over a greater than 100 foot distance; with a 3/8 inch ID hose I could see the slowness. That might be the only problem if trying to plot 10 acres. A larger diameter hose would help with the flow of the water.

Your transit and level rod may be your best bet if you take care to set the transit up properly each time you move it.

A laser setup with at least one laser receptor would be top of the line, but cost more bucks.
Title: Re: Measuring Elevations
Post by: FrankInWI on September 05, 2007, 08:05:26 AM
country neighbors son is a builder.  I'm in flood plain.  They built, after raising the house foundation area about 4 feet.  He mentioned he'd "shoot a line" from his foundation base to my lot when I was ready to build.
He came over with a laser elevation reading tool.  One part was next to his foundation and he tood a pole over to my building site.   He moved the rod up and down untill it "read" the laser line from the sending unit by his mom's house.  We measured down to the ground from there to determine how many feet / inches of fill we'd need to be 2' over flood plain too.  
Fantastic tool, just took a few minutes.  A dummy (like me) could use it too.  
I have to believe Home Depot, or a very large builder's lumber yard, would rent these laser set ups out  as a tool.  Many small builders in this area, and I don't thing they all have these.  
Title: Re: Measuring Elevations
Post by: FrankInWI on September 05, 2007, 08:09:06 AM
http://www.amazon.com/Spectra-Precision-CR600-Combination-Receiver/dp/B0000DYVNI
Title: Re: Measuring Elevations
Post by: glenn-k on September 05, 2007, 09:41:05 AM
I only paid about $400 at HD for a very good laser kit with a receiver, rotary laser, tripod, stick and other accessories.
Title: Re: Measuring Elevations
Post by: MountainDon on September 05, 2007, 04:17:33 PM
This one probably. I've looked at it and am still coveting it.  (where's the drool emoticon?)


http://contractorservices.homedepot.com/StoreProducts/ProductInfo.aspx?cid=1021561&pid=afdd2745-0b99-4694-8e93-284c012172d2
Title: Re: Measuring Elevations
Post by: glenn-k on September 05, 2007, 04:30:31 PM
Somehow they hijacked your link, Don.  Try this one.  A very good set.

CST Berger

http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100015661
Title: Re: Measuring Elevations
Post by: RonDay on September 06, 2007, 03:37:34 PM
QuoteSomehow they hijacked your link, Don.  Try this one.  A very good set.

CST Berger

http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100015661

Looks like it, Glenn, and not terribly expensive, especially with an 800 foot range. It should also be much easier and quicker to setup than an older optical transit level, plus using it could be a one person operation.

Thanks
Title: Re: Measuring Elevations
Post by: glenn kangiser on September 06, 2007, 06:46:46 PM
It is manual leveling so be sure to recheck every so often, but a great laser level.