Shipboard line-transect distance sampling methods are commonly used to estimate populations of cetaceans. One of the assumptions of these methods is that all animals on the trackline are detected, but this is not always the case (especially for cryptic species). Mark Recapture Distance Sampling (MRDS) is a method that uses a secondary observation team to identify the fraction of animals detected on the trackline when it is suspected that animals have been missed. During typical visual line transect methods, MRDS use a secondary visual observation team to understand the fraction of animals on the trackline that are missed by the primary team. In this paper (https://link.springer.com/article/10.1007/s10651-020-00443-7), acoustic detections from a towed hydrophone array are used as the secondary 'observation' platform.

One component of the methods presented in this paper estimates the trackline detection probability p(0) for different levels of an additional variable such as Beaufort Sea States (as presented in Table 2). This was not part of the MRDS output in R. How can these methods be replicated? Specifically, if I have completed MRDS analysis for my dataset, how can I estimate trackline detection probability for individual Beaufort sea states (or other variables with multiple levels)?