What Color Light Works Best for Outdoor Data Transmission Over Long Distances?

[Bern1937]

I am looking for ideas and suggestions on using light for data transmissions. Range will be up to 500 feet, during daylight hours, and outdoors. Want to use relatively common LEDs and diode detectors, due to pricing. The sending end will be moving and sending out light 360 degrees. The receiving end will have a very basic and crude tracking system, so possibly a very simple and broad focus lens can be used. What I am looking for is thoughts on what color of light to use. Since there will be high ambient light can I use a certain color/frequency and some type of filter to get a better signal to noise ratio than if I just use white and a sensor that will look at all the background light? --- Also has anyone been able to get long range, using simple systems without the use of lenses? Your thoughts and ideas ? ? ? ? ? ?

 

[rumborak]

I'm assuming this is for a fun project? There's a ton of commercial products out there that do just that, on a level that is far beyond what you would ever be able to achieve with a homegrown device.

That said, regarding your question, you could start by looking at the absorption spectra of normal air, and then choose the wavelength with the least absorption.

 

[berkeman]

I am looking for ideas and suggestions on using light for data transmissions. Range will be up to 500 feet, during daylight hours, and outdoors. Want to use relatively common LEDs and diode detectors, due to pricing. The sending end will be moving and sending out light 360 degrees. The receiving end will have a very basic and crude tracking system, so possibly a very simple and broad focus lens can be used. What I am looking for is thoughts on what color of light to use. Since there will be high ambient light can I use a certain color/frequency and some type of filter to get a better signal to noise ratio than if I just use white and a sensor that will look at all the background light? --- Also has anyone been able to get long range, using simple systems without the use of lenses? Your thoughts and ideas ? ? ? ? ? ?

Can you say more about the project? Why do you want to use light instead of RF links? What datarate do you need to support? What kind of data is being transmitted?