A modified TCAR method to improve the NL ambiguity resolution over medium-long baseline is presented. The estimated DD ionospheric delay derived from the Kalman-filter floating solution is adopted to modify the floating NL ambiguities. Modified by the smooth DD ionospheric delay, the NL ambiguity residuals are mostly within 0.5 cycles over medium-long baselines, showing a significant improvement in contrast to the classical TCAR method. The positioning performances of the modified method are even better than the LAMBDA method over 72 and 634 km baselines. As the ambiguity can be correctly fixed just after several epochs, high-precision positioning can be achieved in a very short time.

提出了一种改进的TCAR方法，可在中长基线上提高NL模糊度分辨率。从卡尔曼滤波器的浮动解推导出的DD电离层延迟估计值用于修正浮动NL模糊度。通过平滑的DD电离层延迟，在中长基线上，NL模糊残差大部分在0.5个周期内，与传统的TCAR方法相比，显示出显着改善。在72和634 km的基线上，改进方法的定位性能甚至优于LAMBDA方法。由于可以在几个时期之后就可以正确地解决歧义，因此可以在很短的时间内实现高精度定位。