单项选择题
A.direction of a target B.distance to a target C.size of a target D.shape of a target
Radar is not only to obtain（），but also to measure their...
单项选择题Radar is not only to obtain（），but also to measure their distance away from you.
A.brightness of objects B.color of targets C.shape of targets D.bearing of objects
Most GPS receivers use the doppler shift of the carrier...
单项选择题Most GPS receivers use the doppler shift of the carrier phase to compute（）.
A.Latitude B.Longitude C.Speed D.Time
Magnets in the binnacles of magnetic compasses are used...
单项选择题Magnets in the binnacles of magnetic compasses are used to reduce the effect of（）.
A.deviation B.variation C.local attraction D.All of the above
