Topic: "Multiple Balloon Measurements of Gravity Waves over New Hampshire" (Video)
ABSTRACT: The undergraduate GreenCube group, with mentorship from professors and engineering staff, have designed and constructed a payload conforming to CubeSat standards. A CubeSat is a small satellite package standard established by CalPoly and Stanford Universities for standardized secondary spacecraft design. The GreenCube is a 30cm x 10cm x 10cm payload which contains a 3-axis magnetometer, a GPS receiver, a ham radio system, and and digitized sensors. For the GreenCube II gravity wave mission flown this August, the sensors were thermistors for ambient atmospheric temperature observations. Together with the GPS data, these thermistors were used in an attempt to measure atmospheric gravity waves over Mt Washington.
Two adjacent GreenCubes were flown on two high altitude sounding balloons which reached approximately 90,000 feet altitude before bursting. The payloads then descended via parachute and were retrieved using the real-time GPS track received through the ham radio system. The balloons flew over the Presidential Range of mountains and were recovered in Maine. The flight time is approximately two hours.
The onboard GPS gathered position and timing data over the entire trajectories of the balloons. Disturbances in the horizontal velocities of the balloons are being used to locate gravity wave fields in the flight path and study their properties. Changes in both position and time of the wave fields can be analyzed by comparing the tracks of the two balloons and payloads. Thermistor data show variations comparable in scale size and altitude to those of the observed velocity variations. We are investigating the relationship between these observed signatures and the expected signatures of orographic (terrain-generated) gravity wave signatures.
In addition to the GreenCube payloads, each balloon also carried a commercial camcorder on its lower secondary payload (designed to carry an emergency locator transmitter (ELT).) These cameras captured HD video of the Earth from the balloon altitudes, including images of cloud formations which bear the signs of atmospheric gravity waves.
In this presentation we will report on the goals and objectives of the GreenCube project; the design and implementation of the GreenCube spacecraft; the logistics and operation of the GreenCube2 mission flown this summer; data analysis of our gravity wave signature data; and plans for future GreenCube designs and flights.