Added support for new cmdline NOPVC, in order to accept data with a non-valid position validity (field 9).
See Coding Notes for more information about this
Driver to decode the absolute or relative positioning message from an iXSea GAPS (Global Acoustic Positioning System), a fully integrated (INS and GPS) portable USBL system.
Two versions of the driver are available, a serial version and a Network version (UDP). The internal working of the drivers are the same except for the data reception.
This section will describe how to decode the absolute positioning message. To decode the relative positioning message, see the related IxSea GAPS USBL drivers