public ObservableCollection <GPS> AvailableGPS()
        {
            List <GPS> availableGPS = GPSCollection.ToList();

            //foreach (var gps in GPSes.GetAssignedUnits())
            foreach (var fg in BSCEntities.FisherGPSViewModel.FisherGPSCollection
                     .Where(t => t.DateReturned == null))

            {
                GPS tempGPS = fg.GPS;
                if (availableGPS.Contains(tempGPS))
                {
                    availableGPS.Remove(tempGPS);
                }
            }
            return(new ObservableCollection <GPS>(availableGPS));
        }
 public List <GPS> GetAllGPS()
 {
     return(GPSCollection.ToList());
 }