This study evaluates the productivity and accuracy of surveys completed with single-base real-time kinematic (RTK) Global Navigation Satellite Systems (GNSS) using four different GNSS constellation combinations: (1) GPS-only, (2) GPS+GLONASS, (3) GPS+Galileo+BeiDou, and (4) GPS+GLONASS+Galileo+BeiDou. For this comparison, we set up a test site consisting of 20 stations ranging with obstructions from low to severe conditions, primarily resulting from trees. Reference coordinates for each station were obtained through a least squares adjustment of total station and static GNSS observations. In the field surveys, we completed fourteen rounds of 30-second RTK occupations on each station across a period of five days in January 2019 using two antennas with a total of four receivers (two per antenna), each set to record a different constellation combination. Observations with the second antenna followed immediately behind the first antenna in order to maintain consistent satellite conditions for all constellation combinations. In comparison to the reference coordinates, we found that additional constellations dramatically improved productivity in the field, particularly in high obstruction conditions where the percent of fixed observations increased with each additional constellation from 15%, 21%, 70%, to 91%. However, the impact of additional constellations on accuracy is less clear from the data. GPS+GLONASS generally produced the smallest RMS values, despite larger bias. Combinations (3) and (4) produced solutions with smaller biases but larger standard deviations as compared to GPS+GLONASS.