We set a threshold to eliminate the gauge errors of steps which resulted from the shaking of smartphone, such that ΔT > T Th Acc _ norm − g > A Th (3).
Sea level height is presented along the y-axis of the diagram, and the tide gauge error, i.e., the difference in sea level height between the two sea level records, is presented along the x-axis of the diagram.
The tide gauge error, i.e., the difference between the reference pressure tide gauge record and the GNSS-derived sea level, for GPS L1 versus wind speed.
The tide gauge error, i.e., the difference between the reference pressure tide gauge record and the GNSS-derived sea level, was then compared to the wind speed for identical epochs (wind speed measurements are available every 10 min).
From Figure 7, it is again apparent that the phase delay sea level better resembles the tide gauge sea level, i.e., the tide gauge error is smaller, than the SNR sea level.
It does not appear that there are significantly less SNR-derived results at higher wind speeds than at lower wind speeds, and there is no visible correlation between the tide gauge error and increasing wind speed.
The tide gauge error for GPS L1 compared to wind speed, both for SNR analysis and phase delay analysis, is presented in Figure 8. Figure 8 Sensitivity of GNSS sea level results for wind speed.
Externally-generated electrons from the flood gun can cause serious errors in the pressures indicated by the gauges; the error can be positive or negative depending on the gauge current-measuring circuit.
In Figure 8, the tide gauge errors of the SNR solution are distributed around zero for wind speeds between 0.5 and 17.5 m/s, which were the lowest and highest wind speeds observed during the campaign, respectively.
