A.Serrated range rings B.Indirect echoes C.Multiple echoes D.Blind sector
单项选择题Which ARPA data should you use in order to determine if a close quarters situation will develop with a target vessel? ()
A.Set and drift of the current B.Relative track information C.Predicted time of CPA D.Initial range of acquisition
单项选择题When you turn on the fast time constant (differentiator) control of a radar it will().
A.enhance weak target echoes and brighten them on the PPI B.reduce clutter over the entire PPI by shortening the echoes C.only suppress weak targets to a limited distance from the ship (sea clutter) D.reduce the beam width to provide a map-like presentation for navigation
单项选择题When will the float-free emergency position indicating radiobeacon be activated after abandoning ship? ()
A.Immediately after floating free B.After about one hour when the salt water activates the battery C.Only when keyed by the radar of another vessel D.Only when daylight activates the photovoltaic cell
单项选择题When using the radar for navigating().
A.the best fix is obtained by using a tangent bearing and a range B.and using two radar ranges for a fix,the objects of the ranges should be close to reciprocal bearings C.and using ranges,the most rapidly changing range should be measured last D.and crossing a radar range of one object with the visual bearing of a second object,the two objects should be 80°to 110°apart
单项选择题When using the ARPA in heavy rain,which action should you take? ()
A.Increase the radar gain to pick up weak echoes through the rain B.Increase the STC setting to reduce close-in spurious signals C.Navigate as though the effective range of the radar has been reduced D.Increase the range of the inner and outer guard rings