// Raul - If state cannot be read from file create a default one
            if (_state == null)
            {
                _state = CreateDefaultState();
            }
            else // Use the state saved in the file, but don't forget to allocate memory for arrays.
            {
                _state.DistanceMeasurements = new double[SonarArrayLength];
                formerDistanceMeasurements = new double[SonarArrayLength];
            }

        /// <summary>
        /// Create default service state
        /// </summary>
        pxsonar.SonarState CreateDefaultState()
        {
            pxsonar.SonarState temp_state = new pxsonar.SonarState();

            // Allocation for Arcos Sensor readings.
            temp_state.DistanceMeasurements = new double[SonarArrayLength];
            formerDistanceMeasurements = new double[SonarArrayLength];

            temp_state.MaxDistance = 4000;
            temp_state.HardwareIdentifier = 0;
            temp_state.TimeStamp = DateTime.Now; 

            // Initialize Sonar readings.
            for (int i = 0; i < SonarArrayLength; i++)
            {
                temp_state.DistanceMeasurements[i] = 0.0;
                formerDistanceMeasurements[i] = 0.0;
            }

            // Raul - P3DX front ring sonar is 180 degress. But lateral transducers are
            // Raul - centered at 90 degrees, so I consider: 196 degrees.
            // Raul - I considered the aperture of one transducer is 16 degrees.
            temp_state.AngularRange = 196;  // 180 plus two halfs of lateral transducers.

            // Raul - Angle increment for sonar transducer rays.
            temp_state.AngularResolution = 1.0; // let's generate one ray per degree.

            // Save state in case it doesn't exist.
            SaveState(temp_state);

            return temp_state;
        }