This shows positioning errors of a dual-frequency receiver at Zhengzhou in the open (left) and authorized (right) services. Top subplot: red, green and blue lines are errors for the east-west, north-south and height components. Middle subplot: 3-dimensional positioning errors. Lower subplot: pink, blue and black lines are DOP values for the east-west, north-south and height components. Bottom subplot: red line is the PDOP value and black line the number of satellites in view.