| 摘要 |
PROBLEM TO BE SOLVED: To obtain pictures of a stable picture quality on the ground by discriminating the state of a line on the ground and transmitting the result to an aircraft and switching data to compressed picture data obtained by space picture compression where degradation of the picture quality is less continued and transmitting data from the aircraft to the ground. SOLUTION: A line quality discrimination circuit 39 discriminates the state of the line in accordance with compressed picture data 19, to which an error correction code transmitted from the aircraft is added, to send line state data 40. A compression control circuit 37 generates a compression control signal 38 from line state data 36 transmitted to the aircraft; and when the line quality is degraded, the compression control signal 38 is sent to a switching circuit 31 so as to select space picture compression data 30 where degradation of the picture quality is less continued. The switching circuit 31 switches time picture compression data 10 of the output of a time picture compression circuit 9 to space picture compression data 30 of the output of a space picture compression circuit 29 to send compressed picture data 32. Thus, degradation of the picture quality is not continued even if the line state is degraded. |
