class="comment">%P.R. Jackson)  Required to stop bad data return when missing GPS and</span>
0107     <span class="comment">%bottom track.</span>
0108     bvbt_indx                           = find(A(zi).Nav.totDistEast == -32768);
0109     A(zi).Nav.totDistEast(bvbt_indx)    = NaN;
0110     A(zi).Nav.totDistENorth(bvbt_indx)  = NaN;
0111     gvbt_indx                           = ~isnan(A(zi).Nav.totDistEast);
0112     A(zi).Nav.totDistEast(bvbt_indx)    = interp1(A(zi).Sup.ensNo(gvbt_indx),A(zi).Nav.totDis