  Ground-based mid-infrared (MIR) astronomical observations require the removal
of the fast time variable components of (a) sky/background variation and (b)
array background. Typically, this has been achieved through oscillating the
telescope's secondary mirror a few times a second, a process termed "chopping".
However, chopping reduces on-object photon collection time, imposes stringent
demands on the secondary mirror, requires nodding of the telescope to remove
the radiative offset imprinted by the chopping, and relies on an often-fixed
chop-frequency regardless of the sky conditions in the actual observations. In
the 30m telescope era, secondary mirror chopping is impracticable. However, if
the sky and background is sufficiently stable, drift scanning holds the promise
to remove the necessity of chopping. In this paper we report our encouraging
drift scanning results using the CanariCam MIR instrument on the 10.4m Gran
Telescopio Canarias and the implications to future instruments and experiments.
