动态坐标校正法提高手持GPS精度

Portable GPS Precision Improving Through Dynamic Coordinate Correction

实验表明部分手持GPS外符合定位精度较低,尤其两次观测同一点的互差一般都会超过其标称精度,在测定地质孔位或小比例尺填图中会出现较大误差。实践过程中,发现手持GPS的外符合精度明显低于内符合精度,前者误差有时高达30m左右,而且不稳定,随机性很差;后者坐标相对误差一般均能达到3～5m的精度。利用手持GPS内符合定位精度高的特点提出一种动态坐标校正法,即每次测量都以几个已知点为校正点重复测量,以此计算坐标转换时的相应参数进行坐标纠正,从而提高手持GPS与地图坐标的吻合程度。

Experimentation indicated that external accordant positioning accuracy of some portable GPS is rather too low.Especially difference between twice surveying of a same point is usually beyond nominal accuracy,thus unexpected error will be in borehole positioning and small scale geological mapping.In experiments,external accordant accuracy of portable GPS is obviously poorer than internal accordant accuracy.Errors of the former sometimes can be about 30m as high,fluctuating and less randomness;while the relative error of the later generally 3-5m.A dynamic coordinate correction method has put forward based on above mentioned features.That is in every surveying must take several given points as correcting point and make repeating observations,then carry out coordinate correction through corresponding parameter calculation in coordinate transformation,thereby to improve coordinate coincidence between portable GPS and map coordinates.