(a) Angular power spectra of the VLA-D array, Effelsberg-100 m, and VLA-Effelsberg combined images toward the representative region near the Galactic center (see Fig. 4). The 2D Kolmogorov-like spectrum is indicated by the dashed black line for comparison. (b) Percentage of missing flux of the VLA D-array data across the Galactic plane covered by the GLOSTAR survey. The horizontal dashed red line indicates a missing flux fraction of 10%.