Illustration of HGPS region superimposed an all-sky image of Planck CO(1-0) data (Planck Collaboration X 2016) in Galactic coordinates and Hammer-Aitoff projection. For comparison, we overlay the HEGRA Galactic plane survey (Aharonian et al. 2002) and VERITAS Cygnus survey (Weinstein 2009) footprints. Triangles denote the Fermi-LAT 2FHL γ-ray sources (Ackermann et al. 2016) identified as Galactic, and stars indicate the 15 Galactic VHE γ-ray sources outside the HGPS region. H.E.S.S. has detected three of these, which are labeled SN 1006 (Acero et al. 2010a), the Crab Nebula (Aharonian et al. 2006b; H.E.S.S. Collaboration 2014a), and HESS J0632+057 (Aharonian et al. 2007; Aliu et al. 2014a). The gray shaded regions denote the part of the sky that cannot be observed from the H.E.S.S. site at reasonable zenith angles (less than 60°). The lower panels show the HGPS γ-ray flux above 1 TeV for regions where the sensitivity is better than 10% Crab (correlation radius R_c = 0.4°; see Sect. 3) and observation time, both also in Galactic coordinates. The white contours in the lower panels delineate the boundaries of the survey region; the HGPS has little or no exposure beyond Galactic latitudes of |b| ≤ 3° at most locations along the Galactic plane.