For high-accuracy geodetic applications, time-variable tropo- spheric propagation delay errors limit global positioning system real- time kinematic positioning accuracy. Potential improvements in position- ing accuracy are evaluated by using the National Oceanic and Atmo- spheric Administration (NOAA) real-time tropospheric corrections (herein called NOAA model) within a multiple reference station network approach. The results are compared with those for modified Hopfield tropospheric model corrections, for six scenarios in three geographical regions in the U.S. National Geo- detic Survey network of Continu- ously Operating Reference Stations, for baseline lengths of 60� 150 km. Analyses are conducted at rover locations for relatively humid days, and misclosures for various double difference observations are com- puted; these observations include each frequency (L1 and L2) and three linear combinations (wide lane, ionosphere free (IF), and geometry free). The effectiveness of the net- work approach is demonstrated, with overall performance improve- ments of 15 and 19%, using the modified Hopfield and the NOAA model, respectively. The IF linear combination, a measure of tropo- spheric and orbital errors, shows a 3% improvement for the NOAA model compared with the modified Hopfield model.