Signal from channel 8 of HIRS/2 on NOAA-14 while viewing deep space during one complete orbit on March 12–13, 1995 (top). Here, “scanpos” is equivalent to “sample”; all 56 samples of one calibration sequence are taken within 6.4 sec. As HIRS gives fewer counts for stronger flux, any intrusion of the Moon in the field of view is easily recognizable by the exceptionally low number of counts. The number of counts from the scan with the Moon in the FOV is plotted in the bottom panel, where it is possible to see that the Moon was fully included in the FOV until scanpos 33. Then it began to slowly move out. At scanpos 10, the scanning mirror had not yet reached its final position and, therefore, the Moon was not fully included in the FOV.