Balloon Fest December 7, 2013

Team 26Learning for Life School

Group 3 – Wolves(Advanced)

Determine Whether GPS Altitude LagsBarometric Pressure and Accelerometer Sensors

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, 2013Team 26 - LFLS Group 3 – Wolves (Advanced)

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, 2013Team 26 - LFLS Group 3 – Wolves (Advanced)

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, 2013Team 26 - LFLS Group 3 – Wolves (Advanced)

-30

-20

-10

0

10

20

30

40

Proof: GPS Altitude Lags!

GPS AltitudeBarometric Pressure

Acceleration Y

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, 2013Team 26 - LFLS Group 3 – Wolves (Advanced)