加拿大诺瓦泰（Novatel）公司于1992年底推出高精度的C／A码窄距相关GPS接收机。近两年的大量实测结果表明：由于采用窄距相关技术，使C／A码达到P码的精度；采用码／载波相位扩散技术，使GPS单频接收的测程达到320km，精度为smm＋1－2PPm，接近双频接收机的精度。这种高精度的 Novatel Inc. of Canada introduced a highly accurate C / A code GPS receiver with narrow range correlation at the end of 1992. A large number of measured results in the past two years show that the C / A code achieves the accuracy of P code due to the narrow-range correlation technique. The code range of single-frequency reception of GPS is 320 km with the code / carrier phase diffusion technology, and the accuracy is smm + 1- 2PPm, close to the accuracy of dual-band receiver. This high precision