USGS Bench Marks for altitude?

[JOE(USA)]

Hi,

I have a Garmin Etrex Cx and I want to calibrate the altitude feature on it. I thought I could find a USGS bench mark in my area and use that. The problem is those markers do not seem to be available on the internet? Does anyone know of a website or a different way to do it accurately? Joe

 

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[hsjrev]

Use this website to find benchmarks in your area. It's very picky on the lat long format.

http://www.ngs.noaa.gov/cgi-bin/ds_radius.prl

 

[cavers5]

Hi,

I like using this one better. You can do it by quad names.

http://www.ngs.noaa.gov/cgi-bin/ds_quads.prl

First, type in the quad name of your area. Then click on your correct quad in the first/top box. If there is only one quad there, you're in luck! Next, I hit submit because I like reading all the old details of the benchmarks, but as you can see, you can restrict your search in the next two boxes before you hit submit.

After submitting, you get a list of benchmarks on that quad. If you know the approximate lat and long, you can click on it to "select it" or you can scroll on down and click "select all." Then, click "Get datasheets."

If you don't know the lat, long, or other data to choose which benchmark you want, then hit "select all" and "get datasheets." The next screen will show you the listing of benchmarks on that particular quad with plenty of details! The beginning of each benchmark "description" is indicated by the new lats and longs. If you look at the end of each benchmark description, there is a physical description of where each benchmark is located. That is often very helpful, because I find that sometimes the lats and longs are good enough to get me in the right area, but the knowing the actual land features helps a lot!

Hope this helps,
Cavers5

 

[Central Ca Ron]

Go to geocaching.com. Go to the benchmark option and follow the prompts. I have found many benchmarks this way.