Help making long range IR sensor and light combo

I am trying to make a IR light and sensor combo for rowing shells (we row backwards in the pitch black in seattle, what could go wrong?) at night to avoid head on collisions (common where I live ). My idea is each boat would have a IR sensor and IR light on the bow. Any time a boat comes into the field of view of the camera, and the camera detects IR light, it would trigger an alert device such as buzzer. Theoretically, it would trigger both boats as they both see each others lights. It needs at least 15 meters of distance, which would be perfect. Ideally it would not trigger for non IR lights (visible wavelength) on the shore. And ideally even work during the day. My problem with the gate type or garage sensors, some of which i have purchased, is that it is detecting a linear beam, and only detects a 1 degree FOV. I need a camera or detector w lens that detects about a 80 degree field of view (40 to port 40 to starboard). Any suggestions would be greatly appreciated.

How can you control this?

3 mm or so Lens will have a 80 degree field of view. Or a wider angle camera w trim built around lens so that it’s field of view is less. Or W an adjustable focal length lens you can zoom in and reduce FOV.

I guess you don't row in rain. fog or snow? Can't remember that ever happening when we lived in the area.

just wondering how you get both boats to sound an alarm with sensors only on the bow? They will all be pointing forward so will not detect each other. For it to work you would need sensor both on the bow and the stern and then you also need to find ir emitters with a greater range than a tv remote and also receivers that are not narrow beam. might it not be easier to use ultrasonic distance sensors or even good old fashioned torches and a photoresistor?

The rain is not heavy and snow is rare but one issue could be reflections off chop/waves. So if this is an issue the sensor may even need to gate the detection to light that persists for a certain time. Hopefully wont be an issue.

The two boats are heading at each other head first. Both sensor and ir light source are on bow pointing forward.
We want to avoid head on collisions.
Do not need anything in stern.

Can’t use visible light. Headlights on boats are a no no as they blind other boats. Just red and green bow lights are permitted. Also visible lights could be detected on bridges street lights etc and would create false alarms.
The city skyline has plenty of lights

Ultrasound would not work well as the shells are extremely narrow and present very little profile to detect w US when moving head to head.

hmm, red and green, so what about using lasers for the emitters and detectors. you can make the beam as narrow or wide as you want and depending on the output power distances can be short or incredibly long. they are compatible with arduino and have been used for sensors and communications before.

You are thinking of visible light. Water absorbs most IR.

I have not worked with lasers but lots of people would be looking at this. Is it ok to look at a laser in the dark? Would it blind you? How would you detect it? And not the other lights out there?

I think lasers (like cat toy or lectures' pointers) would be useless at 1mW: beam is too narrow and mal-focus to widen the beam drops the very low optical power.

It is a very interesting issue. I read one rowing club rules, one states:

  • Lights – bright white lights that shine 360 degrees. These may be 2 lights each shining 180 degrees mounted at the bow and stern. Make sure the boat is visible from the side. In addition a solid red light should be carried on the stern. Spare batteries should be carried and the lights should be tethered to the boat to avoid them being lost overboard. In the event of a light failure the boat must not be moved until the light has been fixed or replaced.

My first guess is that existing lights (hopefully LED) on the "boat" could be modulated and that a rather simple phototransistor + amp + filter + alarm circuitry would provide an early warning. Filter & alarm could be a uC.

Yes I think you are basically on the same wavelength , pardon the pun. I have considered adding a IR led to the existing red and green bow led lights that are currently in Use. The difficulty is in finding the right combination of light source and sensor for the range and field of view.

Unfortunately im pretty new to arduino - just bought my first kit but am fairly handy at household circuitry. I think if I copy some of the existing arduino projects for ir sensors and modify it w my light and sensor it may work.

But it isn’t easy. For example this ir light should be bright

UltraFire 940nm LED IR...

but isn’t detected by this gate sensor

Seco-Larm E-931-S35RRQ NIR Reflective Photoelectric Sensor; For outdoors gates, garage doors, etc; Weatherproof (IP66) construction for indoor/outdoor usage; Adjustable sensing distance - Pack of 1

Probably different wavelengths but who has a light wavelength meter? Not me.
So it’s really abiut finding the right available combo of light and sensor.

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