Abstract: An apparatus for multilateration of a plurality of P objects, each having a transmitter device, and each transmitter device transmitting a signal, the apparatus including N sensors, a processing unit, each sensor receiving the transmitted signals and determining receive times of each signal. The processing unit performing steps: A. combining receive times for signals into a chronologically ordered series of message sets, wherein each message sets comprises the receive times of one of the transmitted signals, B. collecting all valid message sets that occur within a predetermined time interval, wherein k denotes a time step, and wherein each valid message set contains receive times from at least N sensors, C. estimating a time offset vector Ok comprising time offsets Oki of the receive times of the N sensors at step k and i=1 to N by processing message sets, and D. outputting a position of the objects.