Abstract: Communication systems and methods for high-data-rate, high-efficiency, free-space communications are described. High-speed optical modems and automatic repeat request can be employed to transmit large data files without data errors between remote devices, such as an earth-orbiting satellite and ground station. Data rates over 100 Gb/s can be achieved.

Abstract: Communication systems and methods for high-data-rate, high-efficiency, free-space communications are described. High-speed optical modems and automatic repeat request can be employed to transmit large data files without data errors between remote devices, such as an earth-orbiting satellite and ground station. Data rates over 100 Gb/s can be achieved.

Abstract: A satellite in low-Earth orbit (LEO) or medium-Earth orbit (MEO) with a modern image sensor and/or other remote sensing device can collect data at rates of 10 Mbps or higher. At these collection rates, the satellite can accumulate more data between its passes over a given ground station than it can transmit to the ground station in a single pass using radio-frequency (RF) communications. Put differently, the sensors fill the spacecraft's memory faster than the spacecraft can empty it. Fortunately, free-space optical communications signals can carry far more data than RF communications signals. In particular, a spacecraft can transmit over 1 Tb of data in a single pass using burst wavelength-division multiplexed (WDM) optical signals. Each burst may last seconds to minutes, and can include tens to hundreds of WDM channels, each of which is modulated at 10 Gbps or more.

Abstract: A satellite in low-Earth orbit (LEO) or medium-Earth orbit (MEO) with a modern image sensor and/or other remote sensing device can collect data at rates of 10 Mbps or higher. At these collection rates, the satellite can accumulate more data between its passes over a given ground station than it can transmit to the ground station in a single pass using radio-frequency (RF) communications. Put differently, the sensors fill the spacecraft's memory faster than the spacecraft can empty it. Fortunately, free-space optical communications signals can carry far more data than RF communications signals. In particular, a spacecraft can transmit over 1 Tb of data in a single pass using burst wavelength-division multiplexed (WDM) optical signals. Each burst may last seconds to minutes, and can include tens to hundreds of WDM channels, each of which is modulated at 10 Gbps or more.