I am working on a project where we want a RF transceiver on the AUV for communicating with the ground station when its on the water surface.
I am looking for RF modules that can work in proximity to water body and can provide transmission range of 5 km with throughput of 10 Mbps.
Can you please suggest me some OEMs that make long range RF transceivers. Also, how do other AUVs use RF with antenna being just some centimetres above from water surface?
I talked with one RF OEM, he mentioned that due to fresnel zone clearance issue we cannot have RF communication for than 200 m for antenna being 25 cm above water. He said that for 5 km range the the fresnel zone radius is 10 m so antenna on AUV should be 10 m above water surface which is not feasible in our application.
So how do other AUVs have RF communication for long range?