There is a 4 position rotary filter wheel with one clear and three nd filters.

有4轮的位置旋转过滤器与一个明确的和三个nd滤镜。

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The efficiency of differential global position system (DGPS) a nd Kalman filter on improving GPS receiver's positioning accuracy are verified.

验证了DGPS和卡尔曼滤波器在提高GPS接收机定位精度方面的有效性。

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Same setup, same time of day, but this time I used a polarizing filter along with a Hitech 0.6 soft ND grad.

同样设定，同样时刻，但是这次我与HITECH 0.6软的ND一起使用了一个偏振滤光镜。

youdao

Same setup, same time of day, but this time I used a polarizing filter along with a Hitech 0.6 soft ND grad.

同样设定，同样时刻，但是这次我与HITECH 0.6软的ND一起使用了一个偏振滤光镜。

youdao