  The Simons Observatory (SO) is a cosmic microwave background experiment
composed of three 0.42 m Small Aperture Telescopes (SATs) and one 6 m Large
Aperture Telescope (LAT) in the Atacama Desert of Chile. The Large Aperture
Telescope Receiver (LATR) was integrated into the LAT in August 2023; however,
because mirrors were not yet installed, the LATR optical chain was capped at
the 4K stage. In this dark configuration we are able to characterize many
elements of the instrument without contributions from atmospheric noise. Here
we show this noise is below the required upper limit and its features are well
described with a simple noise model. Maps produced using this noise model have
properties that are in good agreement with the white noise levels of our dark
data. Additionally, we show that our nominal scan strategy has a minimal effect
on the noise when compared to the noise when the telescope is stationary
