 The trend in spatial data accuracy has improved from meters to centimeter levels in recent decades due to the use of LADAR data and aerial systems for imagery and topographic models, which rely on high-precision GNSS technologies. Low-cost dual-frequency multi-constellation receivers have decreased rapidly in cost, making centimeter-level accuracies economically affordable for remote sensing, ground support, field data collections, and classroom instruction. However, assessing the performance of these new receivers is challenging due to the lack of a reference source of higher precision and accuracy than the low-cost GNSS receivers themselves. In this study, a low-cost receiver antenna was evaluated using height modernization monuments in South Carolina, resulting in 2.2 cm IMSE in both horizontal and height dimensions with 95% confidence level accuracies of 3.7 cm and 4.2 cm, 95% respectively. Performance tests in the mountains revealed issues with cellular connections, availability of reference sites, and satellite signal occlusion from mountains that also affect more expensive receivers. This article was authored by Michael E. Hodgson. We are article.tv, links in the description below.