  HI intensity mapping (IM) is an exciting new probe that could revolutionize
the future of cosmology. However, the relative faintness of the HI signal when
compared to foregrounds of astrophysical or terrestrial origin will make HI IM
extremely challenging. The imprint of these foregrounds may result in
systematic errors in the recovered cosmological signal. We discuss an IM
simulation pipeline developed at Manchester that can introduce systematic
errors at the TOD level in order to help assess their impact. We will present
results for two potential sources of systematics for HI IM surveys: 1/f noise
and the integrated emission from global navigation satellites.
