Partially resolved route: only one end is known to the reference data.
First and last received points. Two measurements, nothing in between.
'Entry' and 'exit' mark where the station began and stopped receiving the aircraft, at the edges of the antenna's range: not where the aircraft appeared or vanished.
Start and end of contact
An altitude here falls below the ground of the covered area (lowest point: 372 m, the value drops under 300 m): suspect, probable corrupted frame.