The inversion of remote sensing signatures of internal solitary waves (ISWs) can retrieve dynamic characteristics in the ocean interior. The ubiquitous large-amplitude ISWs limit the weakly nonlinear methods commonly used to retrieve wave parameters. We establish the relationship between surface features and internal characteristics of ISWs in laboratory experiments through the correspondence of the remote sensing signatures and the surface velocities of ISWs. The results show that the strong nonlinearity makes the solution of wave-induced velocity inseparable, and ISW theories under the weakly nonlinear assumption are inappropriate to describe strongly nonlinear ISWs from the surface. Therefore, the fully nonlinear model Dubreil–Jacotin–Long equation is used in the retrievals and has been well verified in both the laboratory and oceans. Mooring observations and the model show that stratification conditions differentiate the relationship between remote sensing signatures and ISW parameters in deep and shallow seas.