When parsing .jsf data, there is no slant range could be directly read.

[xyp8023]

In the jsf Sonar Data Message, there is a Sampling Interval dt could be used to calculate the max slant range. Say the number of samples in jsf_sss_ping.port.pings is n, the sound velocity is v:
max_slant_range = dtnv/2
However, it seems that the valid sound velocity is stored in the jsf_dvl_ping.
TODO: 1. add python interface to parse jsf_dvl_ping 2. add c++ and python interface for the function to match the sound velocity from jsf_dvl_ping to jsf_sss_ping.