Which description best matches a Running Fix?

Which description best matches a Running Fix?

• A. Limited Objects Are Available for Taking LOPs and the Vessel Remains on a Constant Course. Advances or Retires a LOP Taken to the Same Object at Two Different Times to Fix the Vessel's Position
• B. A Fix Derived from the Intersection of Three LOPs
• C. Starting Point, Course & Speed, Time & Distance
• D. GPS and Radar Ranges Used for a Position Fix

Answer: (D)

Running fix relies on two lines of position taken from the same object at two different times, using your known course and speed to move the first line forward to the time of the second observation. The intersection of that advanced line with the second LOP gives your vessel’s position. This method assumes you can observe the same object twice and that you can accurately dead-reckon the distance traveled between the observations to advance the first LOP. The description that matches this method talks about having limited objects available for taking LOPs, keeping a constant course, and advancing or retiring an LOP taken from the object at the earlier time to the later time to fix the position. That precisely describes the running fix technique. Other approaches describe different fixes: a fix from the intersection of three LOPs is a standard three-point fix, not a running fix; starting point, course & speed, time & distance relate to dead reckoning data rather than a fix method; GPS and radar ranges describe electronic position fixes rather than the running fix method.

Running fix relies on two lines of position taken from the same object at two different times, using your known course and speed to move the first line forward to the time of the second observation. The intersection of that advanced line with the second LOP gives your vessel’s position. This method assumes you can observe the same object twice and that you can accurately dead-reckon the distance traveled between the observations to advance the first LOP.

The description that matches this method talks about having limited objects available for taking LOPs, keeping a constant course, and advancing or retiring an LOP taken from the object at the earlier time to the later time to fix the position. That precisely describes the running fix technique.

Other approaches describe different fixes: a fix from the intersection of three LOPs is a standard three-point fix, not a running fix; starting point, course & speed, time & distance relate to dead reckoning data rather than a fix method; GPS and radar ranges describe electronic position fixes rather than the running fix method.