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 ? ? ? ? ? ?