Nelson Bench Mark Virtual Cache

N45° 28.051 W122° 42.767

DIFFICULTY: 1, 1

The motivation for this virtual cache is to introduce the wonders of the National Geodetic Survey bench mark program. Your first task will be to go to the NGS search index URL on the Internet. You'll look up the coordinates for a local bench mark and go there to answer a single question for your virtual cache score. You'll want to take a compass with you to the bench mark

1. Go to the following Internet URL: http://www.ngs.noaa.gov/cgi-bin/ds_radius.prl
2. Now, for the central point of your search,enter the coordinates for Marco's Cafe, my favorite local breakfast bistro at N45° 28.051 W122° 42.767. That's the notation we normally use here at geocaching.com and will get you to Marco's should you want to check them out while you're in the neighborhood. Actually, you'll have to enter the coordinates in hddmmss format, which works out to be: N452803 W1224246

   Stipulate a 1.0 mile radius simply to save time in the search and data download. You'll get back a list of all the benchmarks within a mile of Marco's. Notice that you can re-sort the list by distance, which is nice if you later want to find all the benchmarks around your home.

3. Select the NELSON benchmark and download its data. Notice that its coordinates are given to five decimal places for the seconds increment. What kind of resolution does that suggest? (Hint: One second of latitude is approximately 100 feet.) Altitude is listed in meters to one decimal place, or about five inches! (3.28 feet x 12inches x 0.1)
4. What is the altitude of the Nelson bench mark (from the data sheet). Now go to the NELSON bench mark. It's an all-weather cache site in dog heaven. (This might be nice place to check the altimeter reading of your gps. Set your gps right on the brass plaque.)
5. Standing on the bench mark, you will see a prominent sign. What is the true bearing and approximate distance to that sign from the bench mark?
6. E-mail me your two answers and I will validate your find on the cache log. Do not wait for my validation to log your find! Consider your find validated unless you hear from subsequently.