Potential Impact of Global Navigation Satellite Services on Total Power
  HI Intensity Mapping Surveys
  Future total-power single-dish HI intensity mapping (HI IM) surveys have the
potential to provide unprecedented insight into late time ($z < 1$) cosmology
that are competitive with Stage IV dark energy surveys. However, redshifts
between $0 < z < 0.2$ lie within the transmission bands of global navigation
satellite services (GNSS), and even at higher redshifts out-of-band leakage
from GNSS satellites may be problematic. We estimate the impact of GNSS
satellites on future single-dish HI IM surveys using realistic estimates of
both the total power and spectral structure of GNSS signals convolved with a
model SKA beam. Using a simulated SKA HI IM survey covering 30000 sq. deg. of
sky and 200 dishes, we compare the integrated GNSS emission on the sky with the
expected HI signal. It is found that for frequencies $> 950$ MHz the emission
from GNSS satellites will exceed the expected HI signal for all angular scales
to which the SKA is sensitive when operating in single-dish mode.
