Rock Lake Survey

This past weekend we began a physical survey of Rock Lake by establishing a correctable initial point and then running survey line out at several depths, notably 100', 135' and 150'. We collected about 80 data points on some outstanding effort by James Williams, Ron Tackett, John Adsit, Nick Benni and Dan Baldwin. Next month should be even more fruitful as we will have established our methods and can continue to improve our techniques. I will produce a 100' contour in the next few days as we have more data there than any where else.

Thanks to all!

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Replies to This Discussion

Permalink Reply by James Williams on January 18, 2011 at 9:54pm

I found the software that I used to make my 3d topographic map of Blue Hole.

http://field.hypermart.net/

It may work pretty well for this project.

Permalink Reply by George K. Watson on January 19, 2011 at 7:13am

Looks just right. I will be interesting to see if we can take or eventual mesh and surface and texture it. We are going to need Justin's 600' reel next month.

Permalink Reply by James Williams on January 21, 2011 at 8:01pm

This has some promise as well:

https://wci.llnl.gov/codes/visit/home.html

Permalink Reply by George K. Watson on January 25, 2011 at 7:18am

I have a 600' reel on order for next month. Combined with Justin's this will allow two teams to make good progress simultaneously. I want to branch from the 100' marks and get hemicircular data for 90' and 110'. Getting 120' data would be gravy as we could join it with the 135' data.

Permalink Reply by George K. Watson on February 13, 2011 at 11:20am

Scanned drawing of the 100ft shelf done by Nick Benni

Attachments:

HundredFootShelf2.PNG, 537 KB

Permalink Reply by George K. Watson on February 21, 2011 at 6:56am

This weekend we gathered a tremendous amount of data, collecting 163 points at the 90, 110 and 120 ft depths these half contours are now finished and we should be able to generate our first 3d mesh this week. There were 6 dives, involving about 8 hours of in water time over three days. Kudos to James Williams and Justin Daniels for their hard work.

Kudos too to the MX rebreather. I find it's nice to have for the very difficult work of installing survey line under the huge ceilings and into the deep corners of this environment.

Permalink Reply by James Williams on February 23, 2011 at 2:32pm

Here are the survey points that we have of Rock Lake to date. The numbers beside the dots are the survey point names and are in a depth.distance format. For instance 100.28, represents 100' run and the 28th knot, or 280 feet in horizontal distance. The actual depths vary and aren't represented in this map. Enjoy.

Permalink Reply by Geoff on March 22, 2011 at 6:37pm

Started building a mesh out of the existing data. There are still some corrections that need to be applied to the data, but here is what we have for 90-130 feet.

Permalink Reply by George K. Watson on March 22, 2011 at 6:45pm

Looks really good!

Permalink Reply by George K. Watson on March 22, 2011 at 7:40pm

So there are two corrections needed immediately. One is based on the belief that the kevlar line does not stretch as much when wet so the 90' data is pretty skewed and the other is the origin correction. The origin correction can be done in a single dive. We can calibrate the line then we just need to know what kind was used. A terminus correction of some sort at the west descent line will be needed at some point.

Permalink Reply by James Williams on December 6, 2011 at 11:42am

Maybe we should utilize this... or maybe modify it to get a 360 degree view. :)

http://www.mantasonar.com/diveray.htm

Permalink Reply by George K. Watson on December 6, 2011 at 12:37pm

Does not give a depth rating that I can see, but with good fixed points, it would be handy!