Symmetrical multi-path method for determining the distance between two transmitter-receivers

Transmitter-receiver for determining the spatial distance from a second transmitter-receiver within a distance range in the order of magnitude of 10 km comprising:

• a transmitting unit, configured
• to set off at least one first signal round by transmitting a respective first request data frame, containing a sequence of at least two signal pulses with a predetermined pulse time interval, at a first request transmitting time (TTA1, TTB2) to a second transmitter-receiver,
• a receiving unit configured
• to monitor the receipt of a first reply data frame sent in reply to the first request data frame from the second transmitter-receiver and to ascertain a first reply receiving time (TRA1) relative to the first request transmitting time (TTA1,) allocated to the receipt of the first reply data frame,
• the transmitting unit being additionally configured,
• after receipt of a second request data frame from the second transmitter-receiver setting off a second signal round, to transmit a second reply data frame, containing a sequence of at least two signal pulses with a predetermined pulse time interval, with a reply time interval (TreplyA2) of an allocated second request receiving time (TRA2) of the second request data frame to the second transmitter-receiver,
• after receipt of a first request data frame from a second transmitter-receiver setting off a first signal round, to transmit a first reply data frame, containing a sequence of at least two signal pulses with a predetermined pulse time interval, with a reply time interval (TreplyB1) relative to an allocated first request receiving time (TRB1) of the first request data frame to the second transmitter-receiver and on receipt of the first request data frame from the second transmitter-receiver to set off a second signal round by transmitting a second request data frame, containing a sequence of at least two signal pulses with a predetermined pulse time interval, to the second transmitter-receiver at a second request transmitting time (TTB1),
• the receiving unit additionally being configured,
• to monitor the receipt of a second reply data frame sent from the second transmitter-receiver in reply to the second request data frame and to ascertain a second reply receiving time (TRB2) relative to the second request transmitting time (TTB2) allocated to the receipt of the second reply data frame,
• and the transmitter-receiver being configured to transmit the first and the second reply data frames with a predetermined value of the reply time interval relative to the respective request receiving time with a chronological precision, at which the reply time intervals (TreplyA2, TreplyB1) on the part of the first and second transmitter-receivers in the signal rounds are either identical or have a difference, in the case of performing more than one signal round set off by each transmitter-receiver an average difference, the amount of which is a maximum of 200 microseconds.