低精度SINS初始对准/GPS双天线测向互辅算法

针对低精度捷联惯性导航系统无法实现航向角的自对准和全球定位系统双天线测向需要较长时间的初始化问题，研究了二者互相辅助的新算法．即利用SINS初始对准时的俯仰角信息和已知基线长度进行约束，通过搜索基线姿态角，在二次残差最小的条件下快速确定基线航向角，然后利用该航向角辅助SINS的快速初始对准．建立了互辅算法模型，论述了互辅原理，推导了相关公式．通过实验比较，验证了新算法的正确性及可靠性，30s内得到了0.2°的俯仰角和航向角误差，100s内实现了低精度SINS的初始对准，且算法简单，实用性强．

Interact arithmetic of low-accuracy SINS' initial alignment and GPS orientation measurement with two antennas

The low-accuracy strapdown inertial navigation system' (SINS) heading angle can not be achieved in the process of initial alignment, also the GPS direction finding with two antennas requires a long time for initialization. As to that, a new arithmetic is proposed in order to acquire the heading angle faster: the heading angle of the baseline is fixed quickly assisted by the baseline length in the condition of the least square error by searching the attitude; also the attitude is confined by elevation information from SINS' initial alignment. Then the heading angle is used in the SINS' initial attitude. The model is established, the principle of the new algorithm is discussed, and then some correlative expressions are induced. Experiments indicate that the new method proves proper and credible with simple algorithm and high practicability. The error is no more than 0.2°in pitch precision and yaw precision within 30 sec and initial alignment is accomplished within 100 sec.