Velocity-integrated intensity channel maps of the MWISP ¹²CO (1–0) emission in the large-field observations. The integrated velocity range is written in the bottom-left corner of each panel (in km s⁻¹). The plotting scale for each panel is same (from −2 to 9 K km s⁻¹). In each panel, the dashed grey square shows the area of deep mapping observations, while the red ellipse shows the position and size (7′ × 5′) of the Crab Nebula.