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Space Cadets. Temperature, Pressure, Humidity & Imaging. Ali Javed Ravneet Singh Brock Couvillion Dean Slama. OBJECTIVES. To fly a balloon payload up to an altitude of 100,000 ft to photograph, measure, and record temperature, pressure, and humidity
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Space Cadets Temperature, Pressure, Humidity & Imaging Ali Javed Ravneet Singh Brock Couvillion Dean Slama
OBJECTIVES • To fly a balloon payload up to an altitude of 100,000 ft to photograph, measure, and record temperature, pressure, and humidity • Identify trends at various atmospheric layers.
MISSION GOALS • Study the relationships between the temperature, pressure, humidity, and altitude ranging from 0 to 100000 ft in an effort to identify trends at various layers of the atmosphere using a balloon payload. • Launched from Palestine, Tx.
Science Objectives • Determine the variability in temperature with altitude. • Determine the variability in pressure with altitude. • Determine the variability in humidity with altitude. • Determine, from previously recorded data, how often to record the data.
Outline: • Science Background • Ravneet (Temperature/Pressure) • Ali (Humidity/Imaging) • Technical Background • Brock (Overview/requirements) • Dean (Specific Sensors)
Five Layers of Atmosphere • Troposphere • Sea level to 15 km, temperature range: up to -60 °C. • Stratosphere • 15 to 50 km, temperature range: -60 °C to ~ 0 °C. • Mesosphere • 50 to 80 km , temperature range: up to -90 °C. • Thermosphere • 80 to 690 km, temperature range: greater than 1200 °C • Exosphere • Up to 10000 km
Pressure • Pressure decreases exponentially with altitude • At sea level, the pressure is, on average, 1013 mb.
Sampling Rate • The temperature decreases as 0.0061 °C/m in troposphere. With balloon payload ascending at 1000 ft/min, which is 304.8 m/min, change in temperature is 1.08 °C/35sec. Approximately 1 °C of change happens every 35 sec, so the sampling rate does not have to be less than 1 sample/35 sec . • The 1 hPa of change in pressure occurs in less than 40 ms.
HUMIDITY • Amount of moisture the air can hold before it rains. • The most it can hold is 100 percent. • It is measured by a Humidity Sensors ,which indicates the amount of water in the air at any one temperature. • For our mission, we will use a Capacitive Humidity Sensors.
HUMIDITY • During the day near the surface, particularly with clear skies, humidity usually decreases with height. • We can verify this trend by looking at Graph 1.
HUMIDITY AND DAYLIGHT • Humidity in the atmosphere changes as day turns into night, since our payload entire flight time will be during the day, this should not affect our result.
HUMIDITY VS GEOGRAPHY • By researching other locations, we found that geography can affect the humidity of an area.
20 feet 653 FT • Areas that are elevated have a higher percentage of humidity compared to areas of lower elevation. 209 feet
IMAGING CHARACTERISTICS HEIGHT 3700FT
IMAGING CHARACTERISTICS HEIGHT 99000FT
IMAGING CHARACTERISTICS • Factors that can affect the photography of a region include • weather conditions • Speed of wind, • Rain.
DATA COLLECTION • We will measure humidity every 30 seconds. • In addition we will continuously record our flight for the entire time of the flight • which is approximately 4 hours.
Technical Overview & Requirements (Brock Couvillion)
Technical Overview • One sensor each for temperature, pressure & humidity • BalloonSat board as central CPU • Values stored on EEprom with time stamp
Signal to EEProm • Analog signal from sensor represents value • Op-Amps used to condition signals to values ADC can read • ADC converts analog signal to digital value • Digital Value stored in memory of EEProm
Requirements • Entire payload must weigh less than 500 grams • Must be able to survive landing impact & function through turbulence • Sensors must function at temperatures from -70°C to 30°C
Measure temperature using a semiconductor temperature transducer • Range of -70 to 30 degrees Centigrade • Accuracy of +/- 3 degrees • Measure humidity using a humidity-sensitive capacitor sensor • Measure pressure using a strain-sensitive sensor • Range of 0 to 1000 millibars • Accuracy of 1 millibars • All three measurements will be taken simultaneously on intervals of 30 seconds
Conclusion • We plan to review our data and compare our results with our expectations. • In addition we have planned to achieve our goals in a timely manner. • We will follow a calendar and meet dead lines to finish all the required steps.