EBHIS averaged angular power spectrum (black dots) at v_LSR = −3.76 km s^-1. Systematic and statistical uncertainties are estimated quantitatively by the power spectra calculated for emission free portion of the EBHIS data at v_LSR = + 50 km s^-1 (green) and v_LSR = −200 km s^-1 (blue). Data after subtraction of a noise template N(k) are plotted in red. The distribution for k< 0.07 arcmin^-1 (vertical line) is approximated by a power-law with γ = −2.86 ± 0.03.