First load the data into obj so that you have a structure like:

obj.epsi
obj.ctd

If you’re starting with .modraw data, you can get Matlab data by initializing and epsi_class

obj = epsi_class;
obj.f_readData;

To make a plot centered on 60 seconds from the start of the deployment:

tMid = 60; %midpoint of spectral window in seconds since start of deployment
tscan = 4;
plotSec = 30;

obj.Meta_Data.AFE.FS = 320;
obj.Meta_Data.CTD.SN = '0000';
setup = mod_som_read_setup_from_config('bench_config');
obj.Meta_Data.paths.process_library = '~/GitHub/EPSILOMETER';
obj.Meta_Data.paths.data = pwd;
obj.Meta_Data = epsiSetup_fill_meta_data(obj.Meta_Data,setup);

ax = axes;
[~,~,~,ax] = epsiPlot_spectra_at_tMid(obj,tscan/2,tscan);
epsiPlot_spectra_at_tMid(obj,tMid/2+nanmin(obj.epsi.time_s),tscan,plotSec,1,0,1,ax)