For gravitationally lensed type II signals, the phase of the dominant (2, 2) mode and the higher-order (3, 3) mode is offset by $-\pi /12$, or roughly $-0.26\mathrm{rad}$. Using this, we develop a test for type II imagery by allowing the phases of the (2, 2) and (3, 3) modes to vary separately and introducing a new waveform parameter to represent the phase offset between the two. We use simulated, asymmetric mass ratio, precessing signals to show that the test can reproduce the $-\pi /12$ phase offset when detected by three detectors for H-L optimal $\mathrm{SNR}\gtrsim 40$ and $\mathcal{M}\le 30$. We analyze GW190412 and GW190814 using this parametrization, measuring the offset to be ${0.13}_{-0.17}^{+0.22}$ for GW190412 and $-0.05_{-0.22}^{+0.20}$ for GW190814. We also measure the Bayes factor in support of zero phase offset, ${\log }_{10}{\mathcal{B}}_{\mathrm{\Delta }\phi =0}$, to be $-0.14$ for GW190412 and 0.21 for GW190814. This implies our results are not strong enough to confidently argue if either event is a type II image and is consistent with our statistical analysis.

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• General relativity
• Gravitational lenses
• Gravitational waves