a transmission from Earth to a spacecraft or the path of such a transmission
"The satellite engineers adjusted the uplink frequency after the control center lost contact with the rover on Mars."
The portion of a communications link used for the transmission of signals from an Earth terminal to a satellite or to an airborne platform. An uplink is the converse of a downlink. An uplink or downlink is distinguished from reverse link or forward link.
"The control center adjusted the frequency on the uplink to ensure the distress signal reached the orbiting rescue satellite without interference."
To transmit a signal by means of an uplink.
"The technician adjusted the satellite dish to ensure the emergency call was transmitted clearly via the uplink."