In the fastest readout method, speed is considered more important than accuracy so we take only one sample per pixel and reference this voltage to electrical ground (Vss). The detector node voltage applicable in readout method 1 is shown schematically in Figure 25. The unit cell is reset, integrated, and sampled once at the end of the integration ramp.
This method should be used for imaging in the 3-4 
m band and at
M where the high thermal background flux significantly fills the
detector wells in of order the frame readout time. In this situation,
the dominant noise source is photon shot noise from the background
flux, so readout noise is not an issue.
The minimum readout time for this method is 0.2 sec.