When I received data from four distant aircraft I expected the count of positions reported to increase correspondingly but it didn’t.
Today, four aircraft moved along a distant airway in the space of an hour. From the Recent Aircraft Seen table, their distances from me when they left my sight were, 124, 134, 134 and 151 nm. Before they went over, my count in the 120-160 nm range was 3 … and it did not increase. I expected that there would have been 10 - 40 positions reported. (A nearby site did not get any credit for these either.)
My thought is that all four aircraft had been counted as seen earlier in the day. They did not appear to add to the aircraft seen count in that hour. Perhaps the algorithm used to populate the distance polar chart does not recognise positions if any unique aircraft had been previously counted.
Any suggestions or pointers to particulars for the feeder stats?