Characterization of acoustic detection efficiency using an unmanned surface vessel as a mobile receiver platform

Table 2 Summary table of parametric coefficients and smooth terms for Model 2, GAMs testing the effect of operating mode, tether length, thruster, a smoothed function of distance, a smoothed function of distance for each mode, a smoothed function of distance for each tether length, and a smoothed function of distance for each thruster status on detection probability of high- (top) and low-power (bottom) transmissions

Parametric coefficients	Estimate	SE	Z	p-value
High-power
(Intercept)	1.88	0.57	3.30	9.51E−04
Mode = Station-keeping	− 2.25	0.62	− 3.65	2.59E−04
Tether = 2.9 m	− 0.58	0.60	− 0.96	0.335
Tether = 4.6 m	1.22	0.76	1.60	0.110
Thruster = on	− 5.27	0.91	− 5.78	7.26E−09

Smoothing terms	EDF	Χ²	p-value
S (distance)	3.00	33.93	< 2E−16
S (distance): mode = Drifting	1.23E−05	1.08E−06	0.823
S (distance): mode = Station-keeping	1.21E−05	1.27E−06	0.795
S (distance): tether = 1.1 m	3.15E−06	8.97E−08	0.945
S (distance): tether = 2.9 m	2.72E−06	1.66E−07	0.880
S (distance): tether = 4.6 m	1.05	4.97	0.015
S (distance): thruster = off	2.58E−03	2.52E−03	0.259
S (distance): thruster = on	9.58E−02	0.11	0.284

Parametric coefficients	Estimate	SE	Z	p-value
Low-power
(Intercept)	0.54	0.42	1.29	0.199
Mode = Station-keeping	− 1.41	0.44	− 3.20	0.001
Tether = 2.9 m	− 0.15	0.45	− 0.32	0.746
Tether = 4.6 m	1.37	0.56	2.47	0.014
Thruster = on	− 2.91	0.54	− 5.43	5.54E−08

Smoothing terms	EDF	X²	p-value
S (distance)	2.74	25.75	5.62E-07
S (distance): mode = Drifting	1.43E−05	5.56E−06	0.545
S (distance): mode = Station-keeping	1.28E−05	5.81E−06	0.509
S (distance): tether = 1.1 m	0.75	1.65	0.117
S (distance): tether = 2.9 m	3.12E−05	7.49E−06	0.566
S (distance): tether = 4.6 m	0.64	1.35	0.125
S (distance): thruster = off	1.24E−05	7.35E−06	0.432
S (distance): thruster = on	2.17E−05	1.21E−05	0.456

For each model (high- (top) and low-power (bottom) transmissions), parametric coefficients are provided with the estimate, standard error (SE), test statistic (Z), and p-value for the null hypothesis that the parameter is zero and smoothing terms are provided with the estimated degrees of freedom (EDF), test statistic (χ2), and approximate p-value for the null hypothesis that the smoothing term is zero. Italicized p-values are significant at a significance level of 0.05, see Fig. 5 for the partial effects plots of significant smoothing terms

ISSN: 2050-3385