Completeness fraction of recovered artificial sources as a function of the peak flux density of the total added artificial sources. The completeness of the selected fields with different typical noises are shown in different colors. The mean RMS values for the high, low, and typical noise regions are 0.12 mJy beam⁻¹, 0.06 mJy beam⁻¹, and 0.08 mJy beam⁻¹, respectively. 95% completeness limit is reached at a flux density of ~0.35 mJy for the best case G22.5 (red line) and ~0.8 mJy for the worst case G06.5. Typically, the GLOSTAR survey in B-configuration is 95% complete to point sources at the ~0.6 mJy level (i.e., the chosen 7 σ threshold for the catalog in Sect. 3.3), as shown in black line for all the selected fields. See the completeness in Sect. 3.4 for details.