On 2 June 2009 on orbit 1637 around 1352 UTC, NOAA plans to reconfigure NOAA-19 APT channel A. On an orbital basis, the MIRP will be instructed
to select AVHRR channel 2 for APT channel A when crossing over the southern terminator, from night to day, switching from an IR to visible
channel. The MIRP will also be instructed to select AVHRR channel 3 for APT channel A when crossing over the northern terminator, from day
to night, switching from a visible to an IR channel. APT channel B will remain set to contain AVHRR channel 4 data.
In other words:
APT Channel A will contain channel 2 data in daylight and channel 3b data in night
APT Channel B will contain channel 4 data at all times.
Emily D. Harrod
today 15:00 UTC – very low 5 deg pass – confirm VIS/IR image
May 14, 2009 – 15:26 UTC
It seem that, as a bonus, the APT also switched to channel 1 and 3b at the same time. Note that at 1526 UTC, NOAA-19 was rising over the Fairbanks, AK NOAA CDA station. Due to my location, I ‘see’ the same NOAA-19 southbound orbit about 26 minutes later and received the Ch 1 (visible) and Ch 3b (IR) APT pass at 1558 UTC (AOS).