dd = 
            vel: [58x4x52 double]
             sw: [58x4x52 double]
            amp: [58x4x52 double]
             pg: [58x4x52 double]
         status: [58x4x52 double]
        heading: [52x1 double]
          pitch: [52x1 double]
           roll: [52x1 double]
    temperature: [52x1 double]
            HiV: [52x1 double]
        XmtAmps: [52x1 double]
             bt: [1x1 struct]
           dday: [52x1 double]
        ens_num: [52x1 double]
         config: [1x1 struct]
          error: []
dd.bt = 
      vel: [4x52 double]
    range: [4x52 double]
       pg: [4x52 double]

dd.config = 
          yearbase: 2000
            nbytes: 889
                 n: [1x1 struct]
               ofs: [1x1 struct]
             ndata: 5
       nbeams_used: 4
            ncells: 58
              cell: 8
             blank: 4
             pulse: 8
         sysconfig: [1x1 struct]
    vel_multiplier: 0.0025

dd.config.n =
    leader: 63
       vel: 348
        sw: 232
       amp: 232
        pg: 0
    status: 0

dd.config.ofs =
    leader: 14
       vel: 77
        sw: 425
       amp: 657
        pg: 889
    status: 889

dd.config.sysconfig =
    frequency: 150
      hirange: 1
     earthref: 0
           up: 4
      concave: 8