手持GPS在不做控制点的情况下，在相同的坐标参考系统中，相同地物点坐标和高程数据在不同时间

<span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'; mso-bidi-font-family: 'Times New="New"  Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">手持</span><span lang="EN-US" style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New="New"  Roman','serif'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">GPS</span><span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'; mso-bidi-font-family: 'Times New="New"  Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">在不做控制点的情况下，在相同的坐标参考系统中，相同地物点坐标和高程在不同时间<span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'; mso-bidi-font-family: 'Times New="New"  Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">采集的数值有差异吗？差异大吗？主要是什么原因呢？</span></span>

有差异啊，因为星历差、大气层条件差等因素影响，差异大小因手持机而异，一般情况下小于10米吧