Transmission of atmospheric ducted communication signals

A communications system comprising:

• a transmit processor for determining transmit elevation in response to a refractive layer altitude;
• a transmitter array including a plurality of transmitters each for transmitting one of a plurality of transmitted signals in response to the transmit elevation wherein each of the plurality of transmitted signals is encoded using a data signal and one of a plurality of unique synchronization sequences, wherein each of the plurality of unique synchronization sequences corresponds to one of the plurality of transmitted signals;
• and
• a receiver configured for receiving the plurality of transmitted signals, isolating each of the plurality of transmitted signals in response to one of the plurality of unique synchronization sequences corresponding to each of the plurality of transmitted signals to generate a plurality of isolated signals, to combine the plurality of isolated signals to generate a combined signal and to generate the data signal in response to the combined signal.

A method of communications comprising:

• transmitting, by a transmitter array, a first transmission signal at a first elevation angle wherein the first transmission signal includes a first synchronization sequence, a second transmission signal at a second elevation angle wherein the second transmission signal includes a second synchronization sequence;
• and a third transmission signal at a third elevation angle wherein the third transmission signal includes a third synchronization sequence;
• receiving, at a receiver array, the first transmission signal, the second transmission signal, and the third transmission signal;
• isolating, by a processor, a data signal from the first transmission signal in response to the first synchronization sequence, the data signal from the second transmission signal in response to the second synchronization sequence, and the data signal from the third transmission signal;
• determining an first offset in response to the data signal from the first transmission signal, a second offset in response to the data signal from the second transmission signal, and a third offset in response to the data signal from the third transmission signal;
• estimating an optimal transmit elevation angle in response to the first offset, the second offset, and the third offset, and
• transmitting the optimal transmit elevation angle to the transmitter array.