JEITA  CP-3451 - 49 - Default = none '2' = 2-dimensional measurement '3' = 3-dimensional measurement Other = reserved GPSDOP Indicates the GPS DOP (data degree of precision). An HDOP value is written during two-dimensional measurement, and PDOP during three-dimensional measurement.   Tag = 11 (B.H) Type = RATIONAL Count = 1 Default = none GPSSpeedRef Indicates the unit used to express the GPS receiver speed of movement. 'K' 'M' and 'N' represents kilometers per hour, miles per hour, and knots. Tag = 12 (C.H) Type = ASCII Count = 2 Default = 'K' 'K' = Kilometers per hour 'M' = Miles per hour 'N' = Knots Other = reserved GPSSpeed   Indicates the speed of GPS receiver movement. Tag = 13 (D.H) Type = RATIONAL Count = 1 Default = none GPSTrackRef Indicates  the  reference  for  giving  the  direction  of  GPS  receiver  movement.  'T'  denotes  true  direction  and  'M'  is magnetic direction. Tag = 14 (E.H) Type = ASCII Count = 2 Default = 'T' 'T' = True direction 'M' = Magnetic direction Other = reserved GPSTrack Indicates the direction of GPS receiver movement. The range of values is from 0.00 to 359.99. Tag = 15 (F.H)