Abstract: A method for confirming mobile base station integrity in a relative GNSS aircraft landing system, the method comprising: determining a relative position of a first GNSS antenna fixed to the mobile base station with respect to a second GNSS antenna also fixed to the mobile base station by processing signals from a GNSS satellite constellation; calculating a distance between the first GNSS antenna and the second GNSS antenna using the measured relative position; comparing a calculated distance to a known fixed distance; and confirming mobile base station integrity if the calculated distance is within a predetermined threshold of the known fixed distance.

Abstract: A digital signal processing system includes a digital hardware path for processing digital input data to generate respective digital output data, and at least two algorithmically distinct and mathematically equivalent software processes. Each process independently controls the digital hardware path to generate respective digital output data based on the digital input data.

Abstract: A transmitter section of the arrangement includes an altimeter transmitter and a Doppler transmitter. The transmitters both provide frequency-modulated outputs. The altimeter transmitter is linear-FM while the Doppler transmitter is sine-FM.

Abstract: The disclosure teaches a method, and an apparatus for carrying out the method, for determining the time between TO and FRO received waveforms from the time reference scanning beam (TRSB) of a microwave landing system (MLS). In accordance with the invention, the time interval between the TO and FRO received waveforms is determined by correlating the received waveforms with apriori waveforms representative of the TO and FRO waveforms respectively. The apriori waveforms are generated by having a process construct matched filters for these waveforms. A FRO received waveform is used to provide an apriori representation of a TO received waveform and vice-versa. In one embodiment of the invention, the TO and FRO waveforms which are used to construct the matched filters are time reversed.