68-eldo

Again using Google Earth I find it hard to locate the mark. There are two “woods roads” but both of them are too far down the road away from the bridge. Using Street View on Google Earth O can not find any sign of a “woods Road” and the tree may be gone after 40+ years. Other trees may have grown up to confuse the issue. It is also possible the bridge has been rebuilt and is longer than the original. Guessing at the possible location of an older and shorter bridge I get coordinates of 32° 41.622'N 92° 33.128'W for the mark. LSU fan you might check for a date on the bridge, see if it is newer than 1969.

Using Google Earth I measure the bridge at 742.32 ft. or 0.14 miles long which is more than twice the distance “from the bridge to the mark”. So it would seem the center of the bridge is not the point measured from. Did you get a GPS location for the mark?

Wow, nice photos. Thanks for the link Bill.

Did you get any video? Pictures?

I went to scaredycatfilms.com and the tab says “site suspended”. The domain name does not expire until 5/2014 so maybe he forgot to pay the hosting fees.

Disregard

I downloaded it from the app store. Try searching for benchmap, all one word. It works a lot better than Find a Control.

You might want to check the metadata on your photo. I thought I had turned on geotagging for my phone, but when I checked it it was not there. The place I go to to check the metadata is http://regex.info/exif.cgi

Mr. Doyle is an esteemed member of this forum and the Senior Geodesist of the National Geodetic Survey. You can read more on Google here: http://goo.gl/J1XXB Sounds like a fascinating book. Thanks ArtMan

It still works on my old XP machine. Thanks.

If I understand what the Meridian Marks were used for was to calibrate their instruments for north south measurements. That means that the marks are on a north south line, they all have the same longitude. Notice the three coordinates for the marks all have the same west coordinate. N 38 22.099, W 81 37.582 N 38 21.229, W 81 37.582 N 38 19.924, W 81 37.582 Since you have found the center mark, you know the longitude for all the marks. Your search should not deviate more that a little bit from that line. Keep in mind that the marks are visible to each other so look in places that would be visible to the center mark. With the vague distance the North mark may be closer to N 38 22.413 W 81 37.582 which is on top of a hill on the meridian. That would make it more visible form the center mark. The south mark is listed as being on the side of a hill so it is not on the peak. So look on the north side of the hill but stay on the meridian (W 81 37.582). Do not rely on the aerial photos in Google Earth or Google Maps. They are pretty good but may not be exactly right as there maybe some distortion and that will send you off target. Hope all this helps.

The north one may be there too. The area behind the houses seems undeveloped and higher than where Google Earth puts the mark. I assume it must be high to be seen from the center mark.

From those coordinates the north marker should be at N 38 22.099, W 81 37.582 and the south marker should be at N 38 19.924, W 81 37.582. Calculated using GeoCalc 0.9.50. Google Earth puts the north marker between the two houses at 221 & 225 Garrison Avenue and the south marker behind the house at 1857 Loudon Heights Circle. Is that the center marker in the center of the picture? HTH

Hey all - It's released! You can go to GooglePlay and install it! It's called 'BenchMap', and you can get it from the play store here, too: https://play.google.com/store/apps/details?id=com.tsqmadness.bmmaps Cheers all - Mike. Thanks FoxTrot. I just downloaded it from Google Play. I said 0+ downloads when I down loaded it. Am I the first to get it from Google Play?

Back in 2006 Ed Carlson referred me to Chris Guerin at HIDOT and he said there was no online database. But he would forward any recoveries to the proper agency. He then asked if I was interested in looking for some benchmarks for him. I told him I would do that just tell me which ones he wanted me to look for. He never responded. Soon after that I noticed NGS was getting recoveries from HIDOT with the ID of (ROY). I have not been very active because I was tending to personal business the last 6 years. That is done so I hope to get back to it.

Here is a Wikipedia page about the PLSS system. It includes a list of initial points with lat/lon. http://en.wikipedia.org/wiki/Public_Land_Survey_System

A similar Navy accident with a submarine and a sea mount with worse results. The sea mount was not well documented. Some of my co-workers went to Guam to work on this sub. They did not need Electronics types so I was not ask to go.

Try this http://benchmarks.scaredycatfilms.com/index.html

How did you get passed security? Where did you park? I would love to go back up there.

The Topo map as far as how things are laid out in relation to each other is about as accurate as you are going to get for scaled marks. As you probably know the Lat Lon on the data sheet came much later and was determined by someone measuring on the Topo map. That is where the error comes in. Using Acme Mapper to get the Lat Lon is only as accurate as the image of the Topo map is laid over the Lat Lon grid. In my limited experience that is frequently a lot more accurate than the scaled coordinates in the data sheet. Also you can see how the surroundings are and you can get a better idea as to where the mark is. Shirley says within 20 ft and I would agree with that. HTH

To expand on what John said: I use ACME Mapper in the TOPO mode and use the coordinates from the data sheet. That gets me close. Then I look for the X BM indicating a benchmark, and take the coordinates of the X. It is usually closer to the mark than the scaled coordinates. In this case the scaled coordinates are very close to the location shown on the topo map for BM 669 which seems to be the one you are looking for. Hope this helps

In order to log a mark you need to be sure it is the mark you think it is. To do that you need to read any markings on the disk that tell you what it is. On GC there are a lot of logs of the reference marks or a different mark from the one that it is suppose to be. Street view is great for scoping out the location to compare with the description and to see if there is a place to get off the road etc. Any log made only from street view would be unreliable.

..It's still in beta. I'll add and say I DO have 'Find A Control' on my phone, and have had it freeze up on me a couple times too. My biggest problem with it is the storage space it takes up (for no discernible reason) and the limited UI. Is BenchMap to a point where you can put it on Google play? It does not need to be perfect or complete, just reasonably functional. You can always update it later. Many of my apps are getting updates on a regular basis.

But BenchMap is not on Google Play. Find A Control is a little temperamental for me, freezing up when on the Mobil network. It seems to work well in Wi-Fi. But if it does not work well in the field……

Glad to hear you are surviving Harry. I hope things get better for you soon. Isn’t Holograph and Papa Bear in that area too?