Near field navigation system for the approach of an aircraft to a landing platform on a moving vehicle, in particular on a naval vessel, said near field navigation system comprising: - a user segment having at least three receivers (40, 40', 40") and at least three user antennas (41, 42, 43) mounted to a user structure of a said aircraft whereby said user antennas (41, 42, 43) are located at different locations distant from one another and are directed in different directions, - a processing unit provided in the user segment and arranged to be connected to a flight computer of said aircraft, and - at least one additional position detecting unit provided in the user segment, - wherein each receiver (40, 40', 40") is connected to a corresponding, respective one of said user antennas (41, 42, 43) and wherein the receivers (40, 40', 40") are connected to said processing unit, - wherein said processing unit comprises a positioning calculation unit configured to run an algorithm for sensor fusion to merge data from different positioning sources; - said near field navigation system further comprising a base segment provided on a said moving vehicle, said base segment having at least four transmitters (30, 32, 34, 36) with relative positions between them which are fixed and at least four base antennas (31, 33, 35, 37), wherein each transmitter is connected to an associated one of said base antennas (31, 33, 35, 37) and wherein the base antennas (31, 33, 35, 37) are provided on a base structure of said moving vehicle and are positioned relative to each other at known distances; - wherein at least a first one of said transmitters (30; 32; 34; 36) is provided with an inter-transmitter distance measuring unit (30'; 32'; 34'; 36') that is adapted to determine a distance between the antenna of said first one of said transmitters and the antenna of at least one other one of said transmitters (32, 34, 36) of said base segment; - wherein said first one of said transmitters is adapted to transmit the determined inter-transmitter distance data to said receivers (40, 40', 40") of said user segment; - wherein said at least three receivers (40, 40', 40") with the associated user antennas (41, 42, 43) and said at least four transmitters (30, 32, 34, 36) form together distance measuring units, and - wherein the processing unit is adapted to calculate relative three-dimensional position data and attitude data of the user structure with respect to said base structure on the basis of distance data obtained from said distance measuring units and of position data obtained from said additional position detecting unit. - a user segment having at least three receivers (40, 40', 40") and at least three user antennas (41, 42, 43) mounted to a user structure of a said aircraft whereby said user antennas (41, 42, 43) are located at different locations distant from one another and are directed in different directions, - a processing unit provided in the user segment and arranged to be connected to a flight computer of said aircraft, and - at least one additional position detecting unit provided in the user segment, - wherein each receiver (40, 40', 40") is connected to a corresponding, respective one of said user antennas (41, 42, 43) and wherein the receivers (40, 40', 40") are connected to said processing unit, - wherein said processing unit comprises a positioning calculation unit configured to run an algorithm for sensor fusion to merge data from different positioning sources; - said near field navigation system further comprising a base segment provided on a said moving vehicle, said base segment having at least four transmitters (30, 32, 34, 36) with relative positions between them which are fixed and at least four base antennas (31, 33, 35, 37), wherein each transmitter is connected to an associated one of said base antennas (31, 33, 35, 37) and wherein the base antennas (31, 33, 35, 37) are provided on a base structure of said moving vehicle and are positioned relative to each other at known distances; - wherein at least a first one of said transmitters (30; 32; 34; 36) is provided with an inter-transmitter distance measuring unit (30'; 32'; 34'; 36') that is adapted to determine a distance between the antenna of said first one of said transmitters and the antenna of at least one other one of said transmitters (32, 34, 36) of said base segment; - wherein said first one of said transmitters is adapted to transmit the determined inter-transmitter distance data to said receivers (40, 40', 40") of said user segment; - wherein said at least three receivers (40, 40', 40") with the associated user antennas (41, 42, 43) and said at least four transmitters (30, 32, 34, 36) form together distance measuring units, and - wherein the processing unit is adapted to calculate relative three-dimensional position data and attitude data of the user structure with respect to said base structure on the basis of distance data obtained from said distance measuring units and of position data obtained from said additional position detecting unit.