Total station for taking shots in the surf!

I know you said you don't want to spend a lot on bells and whistles you don't need.. but my Trimble instrument has a 360 degree prism and an autolock mode. Once the gun sees the prism, it will automatically follow it as the rodman walks around.. the instrument guy doesn't have to manually track him and point the crosshairs at the prism, it does that automatically. When you need to take a shot, you just hit 'measure' on the data collector and it grabs the shot. Sounds like it would be exactly what you need.

I'll tell you.. if you're still manually writing down angles and distances, a $4k data collector would be well worth the time and investment. I can't imagine manually recording that information any more.

I do not think that reflectorless would do much for you, it is generally more finicky than infra red.

Be aware of the edm settings, Nikon and Leica both have a fast, standard and precise setting which can make a big difference in getting a return signal in difficult environments.

I dunno if putting some sort of homemade shield behind the prism might help but it is something I might try if I were in your shoes.

if the robotics don't work well in the glare, not to mention the saltwater damage to an expensive instrument, try a manual edm with a reflectorless measurement to a large kodak gray card. might be just the ticket. the big card will allow for some oscillations, but you might have to do something about the reflectorless measurement tolerancing

Are you hirin'? I could do the surf thing for you!!!

Just a few ideas. Get a WIDE beam instrument. NOT a narrow beam one. Get one that is pretty water proof. The salt spray in that environment is hard on them. Get a FAST one, that shoots the dist real fast.

BUILD a special pole, with a base that is 4' across, and has a spike in the sand. Surfer goes out, drops the pole to the bottom, and sort of climbs up it, and his weight and the bottom keeps it MORE stationary.

How high is the surf? How deep is the water, in the trough? Do you like this job?

Nate

Put it on track then all you have to do is hit "store".

I am in the habit of day dreaming waiting to get the shot so sometimes I find myself just standing there while Trimble is waiting for me to simply hit store.

As I was vacationing on St. Pete Beach last October, I watched a survey crew perform the very task as you describe. I sure felt for the rodman as he got further and further out.

I don't think I'd take my 360° glass in that environment, I might even just use a 25' rod and read stadia.

My thoughts are to use a reflectless gun. Mount something shinny around 12" by 12" to a PVC pipe or prism pole with a cross hair. a little movement on a target that big should not affect the shot.

Lots of good deals on older Topcons on ebay or other places.
Some have been listed in this forum.
Hard to beat them for a quick (coarse) shot.

NO WAY I'm taking my $800 prism out into the gulf, not to mention the battery in the rod extension.

I like the reflectorless idea, maybe a big target attached to a rod with holes so it doesn't hold water..

My gut says' find another way!! I've "been there, done that" with the rod, both swimming and in a small boat.

I assume that you have range lines on shore that the rod man can see in order to stay on the transect. Is it a big deal to use a small boat to run that last line of shots? It's much easier to hold that rod steady when you're in a boat. If you do all the "foot" work first and then use a row boat to acquire the last row??

Fast = Leica...I've used this for so many transects in water ways that it's the only gun I'll use.

For the other posters, he's not putting the gun in the surf, sillies...

I would not use refelctorless either, you will end up with returns that you don't want, or no shot at all..

Don, someone mentioned using the Trimble 360 active prism. I wouldn't even think of that. one wave over that thing and it's battery pack and you'd be out about 1500 bucks.

haha, that's just crazy, thinking that you can subject this equipment to salt water....

We used to do transects for dredging using a small aluminum boat, the old wild edm and shots about 300' to a triple glass in the boat on a a 25' rod...and that wasn't easy. So I decided to try swimming the cross section with the rod and glass, way harder!!!

Couldn't you just record the information in a field book using old school stadia methods?
Or perhaps you could record the information by hand in the data collector.

[sarcasm]Get the rodman a scuba setup and let him stand on the floor. Or run a long snorkel up the rod.[/sarcasm]

If you are actually going to take shots in the surf, the ONLY equipment that I would use would be those obviously stolen units on Craigslist and the eBay Mexican specials.

Glad to know I'm not the only space cadet out there! I use auto store often and when I have to swap out batteries that next shot tends to get me upset as to why it won't store....

Wow thanks for all the input everybody! I'll try to summarize my responses to everyone in this thread.

The Nikons that we tried were tuned to the correct EDM setting based on discussions with the manufacturer (we didn't use precise). For the amount of shots we take, writing them down is not that big of a deal.

We actually tried a leica 360 degree prism, but it was actually worse than a standard prism!

A shield behind the prism would help, but the problem is the added weight on top of the rod makes it more top heavy and it would act like a kite in the wind (its always blowing there). There is usually always surf in the 2-6 ft range with short period (<7 seconds), but we try to pick the calmer days.

My concern with the reflector-less prism is that the beach is short with a steep foreshore and as a result background behind the prism tends to water and not horizon, and I would be concerned about false returns off the ocean surface behind it (anyone have real world experience with this?). We can make the rod taller, but then it becomes more unstable and difficult for a swimmer to hold steady in the surf when there is a strong longshore current.

foggyidea - small boat not feasible in this surf though we have thought about it. Thanks for the leica recomendation....someone else recomended them to me for this application and I will look into it.

This survey is always a grind on people and equipment but I enjoy it!

Get a modern robotic, set it to fast or track mode, then wander along the shoreline with the data recorder taking shots as your swimmer is ready (and keeping an eye on them for safety). Most recent instruments should be able to get the shot in under a second. eg: The Leica 1200 is 0.15s for a shot on tracking mode and will follow a moving prism.

Grab a cheap and large 360º prism (maybe the Bear brand ones) and clean it well after each use.

Can't believe you're still writing stuff like this down in a notebook. That's basically begging for another, more efficient company to wander in and take your work.

Oh yeah, and definitely not reflectorless for this work.

What if you screwed bike refelctors to a thin piece of plywood and screwed that to a piece of PVC pipe, make it as long as you want. I have used bike reflectors before, with a Lieca 1100 (but it was on dry land)

Nate, I think you're onto something with the wide-based "surf rod." It would take some playing around to get the design right, and it would be odd-looking, but it would probably work as long as the swimmer was nimble and the waves were not too high.

Water resistance would have to be kept to a minimum, so the base would need to be an open framework or a tripod, preferably something that would fold up. The device should be tall enough that 6 ft. or so would be above the water, partly to stay clear of reflections from the water surface and partly to allow climbing room. Climbing steps would be needed.

As you suggest, with the swimmer's body out of the water or nearly out, most of his weight would be on the rod/tripod to help stabilize it, and there would not be much surface area to catch the waves and currents. He would have to set the apparatus down and then climb up on it quickly to avoid being knocked over.

The device would be fairly bulky, and so should have some positive buoyancy to enable the swimmer to push or tow it. A prototype could be made out of wood.