Apt » History » Version 3
PASCHOS, Alexandros, 03/02/2016 11:42 PM
| 1 | 1 | PASCHOS, Alexandros | {{toc}} |
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| 3 | 2 | PASCHOS, Alexandros | h1. *2.2 Automatic Picture Transmission* |
| 4 | 3 | PASCHOS, Alexandros | |
| 5 | 3 | PASCHOS, Alexandros | APT means Automatic Picture Transmission. It is a system, developed in the 1960s, made to transmit low-resolution analog image for weather satellites. A complete APT image takes around 12 minutes to be built up at a rate of 2 lines per second. The data is broadcasted by the satellite. The stream is obtained by the AVHRR/3 instrument. Two channels with a low resolution are emitting all the time using VHF signals at reduced rates (around 120 lines/minutes). |
| 6 | 3 | PASCHOS, Alexandros | The two channels are composed of : |
| 7 | 3 | PASCHOS, Alexandros | * A visible frequency range channel providing APT imagery during the day. |
| 8 | 3 | PASCHOS, Alexandros | * An IR channel providing APT imagery at any time of the day and the night. |