I built an IR communication system . the transmitter controlled by arduino and modulated in 38Khz. the reciever is also controlled by arduino (another one) and demodulting the transmitter signals. everything is great so far. now i want to enlarge the communication range up to 1 kilometer and even farther. how can i reach this range (not involving any optics - telescope and ect.) by replacing to a very powerful led?
or optics is necessary for this kind of ranges?
or optics is necessary for this kind of ranges?