The Role of Antennas on GNSS Pseudorange and Multipath Errors and Their Impact on DFMC Multipath Models for Avionics

Commercial GNSS avionics antenna (Antenna B referred to in the text) mounted in the semi-anechoic chamber at DLR

Group delay variations (normalized to zenith) in ns for (a) Antenna A and (b) Antenna B at 1176 MHz, as measured on the 0.4-m rolled-edge ground plane in Starlab chamber

Pseudorange error (in m and normalized to zenith) obtained from the antenna measurement in Starlab and then processed through the ideal receiver for Antenna A at the L1 band (left) and at the L5 band (right)

Pseudorange error (in m and normalized to zenith) obtained from the antenna measurement in Starlab and then processed through the ideal receiver for Antenna B at the L1 band (left) and at the L5 band (right)

MPSR (in dB) for Antennas A and B (on the left and on the right, respectively) at the L1 band

MPSR (in dB) for Antennas A and B (on the left and right, respectively) at the L5 band

Functional flow diagram of the process to obtain pseudorange errors starting from electromagnetic measurement of the antenna

Multipath versus elevation for E1 and E5a with antenna errors and after antenna error removal (Note: AGDV refers to antenna group delay variations)

3D map of the predicted multipath error (normalized to zenith and with antenna-intrinsic error calibrated out) of Antenna A at the L1/E1 band

Comparison of the 100s smooth multipath error obtained by processing GNSS data from flight tests in code-minus-carrier technique and synthetic data obtained by electromagnetic simulation of the installed performance of Antenna A on A320 aircraft

Different parts of the A321NEO aircraft considered in the installed performance analysis to identify the sources of multipath: a) fuselage only; b) fuselage and tail; c) fuselage, tail, and wings (without winglets); and d) full aircraft

Skyplot of multipath error, calibrated and normalized to zenith, for Antenna A on A321NEO, Position 2, at the L1 band considering: a) fuselage only; b) fuselage and tail; c) fuselage, tail, and wings (no winglets); and d) full aircraft

Multipath on L1 band vs elevation for Antenna A on A321NEO, Position 2, considering: a) fuselage only; b) fuselage and tail; c) fuselage, tail, and wings (no winglets); and d) full aircraft

Predicted multipath error (in m) as a skyplot (top) or versus elevation (bottom) at the L1 band for Antenna A (left) and Antenna B (right), installed in the primary position GPS Position 2 on the A321 NEO aircraft

Predicted multipath error (in m) as a skyplot (top) or versus elevation (bottom) at the L5 band for Antenna A (left) and Antenna B (right), installed in the primary position GPS Position 2 on the A321 NEO aircraft

Predicted multipath error (in m) as a skyplot (top) or versus elevation (bottom) at the L1 band for Antenna A (left) and Antenna B (right), installed in the primary position GPS Position 2 on the A330 aircraft

Predicted multipath error on L5 band (in m) as a skyplot (top) or versus elevation (bottom) for Antenna A (left) and Antenna B (right), installed in the primary position GPS Position 2 on the A330 aircraft

Standard deviation of the predicted multipath error (in m, calibrated for antenna-intrinsic pseudorange error and normalized to zenith) at the L1 band for Antennas A and B from the installed performance simulations on A321NEO and A330 aircraft

Standard deviation of the predicted multipath error (in m, calibrated for antenna-intrinsic pseudorange error and normalized to zenith) at the L5 band for Antennas A and B from the installed performance simulations on A321NEO and A330 aircraft

A350 CAD model with indication of the position of the GPS Position 2 (left) and the ADF position (right)

Predicted multipath error (in m) as a skyplot (top) or versus elevation (bottom) at the L1 band for Antenna A, installed in the primary position GPS Position 2 (left) and in the ADF position (right) on an A350 aircraft

Predicted multipath error (in m) as a skyplot (top) or versus elevation (bottom) at the L1 band for Antenna B, installed in the primary position GPS Position 2 (left) and in the ADF position (right) on an A350 aircraft

Predicted multipath error (in m) as a skyplot (top) or versus elevation (bottom) at the L5 band for Antenna A, installed in the primary position GPS Position 2 (left) and in the ADF position (right) on an A350 aircraft

Predicted multipath error (in m) as a skyplot (top) or versus elevation (bottom) at the L5 band for Antenna B, installed in the primary position GPS Position 2 (left) and in the ADF position (right) on an A350 aircraft

CAD model of a Falcon 200, with indication (center of coordinate system) of the antenna position (Position 1)

Predicted multipath error (in m) as a skyplot (top) or versus elevation (bottom) at the L1 band for Antenna A (left) and Antenna B (right), installed in the GPS Position 1 on a Falcon 200 aircraft

Predicted multipath error (in m) as a skyplot (top) or versus elevation (bottom) at the L5 band for Antenna A (left) and Antenna B (right), installed in the GPS Position 1 on a Falcon 200 aircraft

Simulation of the rays impinging on the antenna on the Falcon aircraft relative to satellites at an elevation of 80°

Standard deviation of the predicted multipath error (in m, calibrated for antenna-intrinsic pseudorange error and normalized to zenith) at the L1 band for Antennas A and B from the installed performance simulations on an A350 (Position 2 and ADF) and Falcon 200 aircraft

Standard deviation of the predicted multipath error (in m, calibrated for antenna-intrinsic pseudorange error and normalized to zenith) at the L5 band for Antennas A and B from the installed performance simulations on an A350 (Position 2 and ADF) and Falcon 200 aircraft

Comparison of the 100-s smoothed RMS of the multipath between measurement and simulations for A350 data on the L1 band using Antenna A

Raw RMS of multipath with simulated data from A350 aircraft, processed using the trajectories and satellite constellations seen in real-life flights during the DUFMAN project