The National Geodetic Survey began publishing a series of experimental geoid (xGEOID) models annually since 2014. The latest experimental model is xGEOID20. The San Joaquin Experimental Range (SJER) in Fresno County, California is surveyed using Static GPS and precise levelling and a local geoid (SJER Geoid) is created. In this study, SJER Geoid is compared against xGEOID20A&B models and the results are tabulated. The results indicate that xGEOID20A&B slopes agree with the GPS/levelling data well even in such a small area. SJER Geoid model agrees with the xGEOID20 models at 7 mm level. The biases about 80 cm are within the expected range between the North American Vertical Datum of 1988 (NAVD88) and North American-Pacific Geopotential Datum of 2022 (NAPGD2022).

国家大地测量局从 2014 年开始每年发布一系列实验大地水准面 (xGEOID) 模型。最新的实验模型是 xGEOID20。使用静态 GPS 和精确水准测量对加利福尼亚州弗雷斯诺县的圣华金实验范围 (SJER) 进行了测量，并创建了本地大地水准面 (SJER Geoid)。在本研究中，将 SJER 大地水准面与 xGEOID20A&B 模型进行比较，并将结果制成表格。结果表明，即使在如此小的区域内，xGEOID20A&B 斜率也与 GPS/水准仪数据吻合良好。SJER 大地水准面模型与 7 毫米水平的 xGEOID20 模型一致。大约 80 厘米的偏差在 1988 年北美垂直基准 (NAVD88) 和 2022 年北美-太平洋位势基准 (NAPGD2022) 之间的预期范围内。