Subscriber Discussion

Can A Camera See A Subject From 3 Miles Away, Offshore?

Jon Dillabaugh

•Aug 26, 2015

Pro Focus LLC

I am from Toledo, OH, and as you may have heard last year, we have issues with our water source, Lake Erie, which is one of the five Great Lakes. The issue stems from an algal bloom on the lake that releases a toxin called microcystin when it's cells are ruptured. A large bloom last August shut down our local water supply for a three day span until the bloom subsided.

An article (link) in our local newspaper is what is prompting this discussion. In this article, it talks about how our water intake crib in Lake Erie used to have residents that lived there. That is no longer the case. The only means of securing the crib are some big padlocks and a security camera on shore that views the crib. It also mentions early in the article that the crib is located 3 miles off the shoreline.

TLDNR;

Do you know of a camera that could see a subject 3 miles offshore in all weather and lighting conditions?

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Brian Rhodes

•Aug 26, 2015

IPVMU Certified

Can cameras be installed on the crib?

Also, I don't quite understand how the algae plays a role in the problem? Are the cameras there to detect the presence of algae near the intake, or people tresspassing on the crib?

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Jon Dillabaugh

•Aug 26, 2015

Pro Focus LLC

In reply to Brian Rhodes

Brian,

The cameras are for security purposes only. They made it sound like Fort Knox with a padlock and a single camera 3 miles on shore.

The algal bloom (which isn't really algae, it's bacteria) is monitored by scientists who take daily samples from a boat.

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Undisclosed #1

•Aug 27, 2015

IPVMU Certified

Fascinating article. Thanks.

First let's get the all weather thing off the table. Clearly, certain conditions, like heavy fog/precipitation are going to severly limit even a camera at 1000 ft. Assuming this is an optical camera there are times when it will be useless.

But could a camera at such a distance be useful to detect unwanted visitors during other condidtions? I would think it could be, but probably there are cheaper ways.

A couple things to note, unless we are talking about paratroopers/frogmen, we are talking about a craft, which should be easier to detect than a figure alone. Also, the crib only has one way in, (unless grappling, in which case that can be done from the far side without detection in any case), so a choke point of sorts. If IR illuminators can be installed at the crib towards the entrance, then that would enable night vision. If not, long range IR laser illuminators could be used.

Of course whether this is what they actually have is a another matter and I support your calling BS on the whole affair on the toledo blog. But to your actual question, I think the answer is yes, sometimes.

From the camera calculator I punched a few datapoints and got this:

Mind you these settings are relatively benign, the Cohu-HD for instance has a focal length of 1667mm, which I would use but the camera calculator is limited to AOV's of at least 1.

Of course the question is why not install a point to point wireless link and camera in the crib? I have no idea. And they already have a 5MP camera on a solar powered floating buoy a few hundred(?) feet away from the crib!!! Apparently aimed towards shore...

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Jon Dillabaugh

•Aug 27, 2015

Pro Focus LLC

In reply to Undisclosed #1

Great info! It seems that buoy cam is 720p for video and 5mp stills. However, it seems rather useless on a floating, bouncing buoy..?

275mm lenses are quite common and inexpensive... right? ;)

I was also wondering if the curvature of the Earth would come into play, as well as large waves? Believe it or not, but 10ft waves are common on the lake.

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Undisclosed #1

•Aug 27, 2015

IPVMU Certified

In reply to Jon Dillabaugh

I was also wondering if the curvature of the Earth would come into play...

Always good to keep in mind, but in this case I think the effect is too small. For every mile the horizon drops about 8 inches or so it's a couple of feet at best, which would be easily offset by a typical mounting height. Also, before on can gain entrance, you need to get onto the landing, which itself is several feet tall:

Believe it or not, but 10ft waves are common on the lake.

Especially when the gales of November come early.

As for mounting, you would want to mount as high as feasible to reduce atmospheric effects and to be able to see over any waves etc. At the same time, the higher the pole, the more sway and vibration, which at the extreme zoom could be ruinous. So a balance would have to be struck depending on the options available on the shore point.

But really Jon, they just need someone to explain hybrid solar/wind powered point-to-point wireless to them, so what are you waiting for?

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Undisclosed #2

•Aug 27, 2015

Pentax has a very expensive long range lens with "atmospheric reduction" capabilities that can combat fog and heat rays which become amplified in long distance.

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John Honovich

•Aug 27, 2015

IPVM

No conventional camera will work at night over such range. I am not even sure if laser based cameras have a chance at that distance.

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Undisclosed #1

•Aug 27, 2015

IPVMU Certified

In reply to John Honovich

What do you mean by conventional, visible light, or not "crazy expensive"?

Eagle vision claims images from 5km on the left (daytime), up to 9pm (nightime) on the right. ;)

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Undisclosed #3

•Aug 27, 2015

In reply to Undisclosed #1

But those night images are showing very well lit targets, that wouldn't be the case in this scenario.

Cameras produce images from light reflected off of objects. Light can travel very long distances, but it also dissipates over distance.

It's not "hard" to capture an object 3 miles away with a camera, people get great shots of the moon all the time. The primary issue is light at the target, and atmospheric conditions between you and the target (and budget of course :) ).

In this case I think you could put together a camera setup that would provide pretty good images most of the time, but you'll be effectively blind at night, or when there is any rain/snow/fog in the air.

IMO, applications like this can be a scenario where the Avigilon HD-PRO cameras are worth considering primarily for the Canon EF lens mount they use. Finding a good quality 200 or 300mm EF lens might be easier than finding a comparable CCTV lens of that length.

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Jean-Philippe Encausse

•Aug 27, 2015

[Fun] Not a security camera but the Nikon P900 have a very impressive zoom for a small form factor: https://www.youtube.com/watch?v=2oScEo5aRek

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Billy Guthrie

•Sep 13, 2015

I n my opinion, the best way I would to tackle this application is to utilize a pair of powerbeam 5AC-500 (PBE-5AC-500) with an IP based PTZ camera. The distance from the water intake crib to the low service pumping station is only ~3miles. At that distance, your RF signal levels would be ~-50dBm(+/- a few dB) with an easy 100Mbps+ through. You could possibly utilize a pair NBE-5AC-19 (Dunno, I have a thing with plastic mounts... not too fond of them) and still get a 33dB fade margin with 29Mbps at -96dBm. The 5AC-500 works fantastic at 5 miles over water (reliably) at 100Mbps of bandwidth (200Mbps Aggregate).

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Dana Varga

•Nov 17, 2015

[Note - Cohu Employee]

The new RISE 4260HD camera from CohuHD Costar can see through atmospheric obscurants at 3 miles (or more).

Here is video at 2.5 miles through fog: Long-range with Defog

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Jon Dillabaugh

•Nov 17, 2015

Pro Focus LLC

In reply to Dana Varga