1. Balloon Fest December 7, 2013 Team 26 Learning for Life School Group 3 – Wolves (Advanced) Determine Whether GPS Altitude Lags Barometric Pressure and Accelerometer Sensors

2. Experiment Purpose - Consumer GPS Receivers Lag User Movement When Displaying Latitude and Longitude Position - Does GPS Altitude Also Lag Barometric Pressure and Acceleration Sensors When Compared to Actual Altitude? Balloon Fest December 7, 2013 Team 26 - LFLS Group 3 – Wolves (Advanced)

3. Experiment Procedure - Move a NASA Small Satellites for Secondary Students (S4) Sensor Payload Vertically Very Rapidly - Record GPS 3-D Position, Barometric Pressure, and Y-Axis Acceleration Balloon Fest December 7, 2013 Team 26 - LFLS Group 3 – Wolves (Advanced)

4. Experiment Data Analysis - S4 Sensor Payload Records GPS 3-D Position, Barometric Pressure, and Y-Axis Acceleration Once Each Second - Compare Times When Altitude Actually Changes vs. Altitude Reported by GPS, Barometric Pressure, and Accelerometer Sensors Balloon Fest December 7, 2013 Team 26 - LFLS Group 3 – Wolves (Advanced)

5. Proof: GPS Altitude Lags!

6. Experiment Results - S4 Sensor Payload Data Clearly Demonstrates that GPS Reported Altitude Does Lag Actual Altitude, As Well As Barometric Pressure and Vertical Acceleration Sensor Data Reporting by About 10 Seconds on Average - Barometric Pressure Is Still a Very Accurate, Timely, and Important Altitude Indicator! Balloon Fest December 7, 2013 Team 26 - LFLS Group 3 – Wolves (Advanced)