PHAT-TACO ExperimentOn board ACES-23

Hannah Gardiner, Bill Freeman, Randy Dupuis, Corey Myers, Andrea Spring

Science PresentationTeam Philosohook

Science Presentation

1. Goals and objectives2. Science background 3. Mechanical Design4. Electrical Design5. Testing6. Calibrations7. Results

Mission Goal

• To study the layers of the atmosphere using an instrumented sounding balloon flown in East Texas during May and to analyze the balloon and the environment surrounding the payload in order to study the relationship between the temperature and humidity profiles acquired during flight.

Objective

• The overall objective is to measure and record humidity, pressure, and internal and external temperature on a sounding balloon flight while taking video of the flight.

SCIENCE BACKGROUND

Science Background: Earth’s Atmosphere

• • Troposphere– Clouds

• Stratosphere– Less humidity &

lower pressure than the Troposphere

http://www.wyckoffschools.org/eisenhower/teachers/chen/atmosphere/earthatmosphere.htm

US Model Atmosphere1 1976

• “A hypothetical vertical distribution of atmospheric temperature, pressure, and density”

• Can calculate properties of the atmosphere– Pressure– Temperature– Density

1U.S. Standard Atmosphere, 1976, U.S. Government Printing Office, Washington, D.C., 1976.

Balloon Radius

• Kaymont 3000 gm sounding balloon

• Ascent rate should be constant during flight

• Has not been in previous flights

Local Area

Regional Area

Our Flight Path

Palestine to Rusk

MECHANICAL DESIGN

Mechanical Drawings - ExternalTop

Front

Mechanical Design - Internal

Mechanical Design - Internal

ELECTRONICS DESIGN

Temperature Sensor Interface

Pressure Sensor Interface

Humidity Sensor Interface

Camera Interface

FLIGHT OPERATIONS: TESTING

Thermal Test

0 20 40 60 80 100 120-50

-40

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0

10

20

30

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Thermal Test: Internal and External Temperature

External Temperature (C)Internal Temperture (C)

Time (Minute)

Tem

pert

ure

(C°)

Vacuum Test

Shock Test

-40 -30 -20 -10 0 10 20 30 400

50

100

150

200

250

300

Shock Test

intempouttemppreshumiditycam

Time (Seconds, 30 before and after drop)

ADC

Coun

ts

FLIGHT OPERATIONS: CALIBRATIONS

Temperature Calibration

External temperature sensor: Temperature(C°) = -.4439(ADC Count) + 28.3Error: ((.013151*ADC Count)^2+(.917709)^2)^.5 C°

Temperature Calibration

Internal temperature sensor: Temperature(C°) = 1.5648(ADC Count) - 364.2Error: 2.07 C° (error variation because of ADC Counts is very small)

Pressure Calibration

Pressure

Counts

Pressure Sensor:Pressure(Atm)=.0039464(ADC counts)-.002953703Error=((1.98378e-5*ADC counts)^2+(.002055339)^2)^.5 Atm

Humidity Calibration

Humidity

Counts

Humidity Sensor:RH(%)= 0.4003(ADC count) – .1047Error: ((0.01453*ADC count)^2+(2.706038)^2)^.5%

RESULTS

0 5 10 15 20 25 30 35-20

-10

0

10

20

30

40 Internal Temperature vs Altitude

Internal Temper-ature Ascent

Internal Temper-ature Descent

Altitude (km)

Temperature (°C)

0 5 10 15 20 25 30 35-80

-60

-40

-20

0

20

40External Temperature vs Altitude

External Tem-perature Ascent

External Tem-perature De-scent

Altitude (km)

Temperature (°C)

0 5 10 15 20 25 30 35-10

-9-8-7-6-5-4-3-2-10123456789

10

Ascent Lapse Rate vs Altitude

Altitude [km]

LapseRate

[C/km]

Lapse rate averaged over one kilometer

RED line is the expected value from US standard atmosphere

Tropopause begin13.6 km (44600 ft.)

Tropopause end18 km (59000 ft)

12 13 14 15 16 17 18 19 20 21-70

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0

External Temperature in the Tropopause (13-20 km)

Tropopause Ascent

Tropopause Descent

Altitude (km)

External Tem-perature

(°C)

0 5 10 15 20 25 30-80

-60

-40

-20

0

20

40

NOAA Data Noon 5/24Temperature vs Altitude

Altitude (km)

Temperature (°C)

0 5 10 15 20 25 30 350

200

400

600

800

1000

1200Pressure vs Altitude

Pressure Ascent

Pressure Descent

Altitude (km)

Pressure (mbar)

0 5 10 15 20 25 300

200

400

600

800

1000

1200

NOAA Data Noon 5/24Pressure vs Altitude

Altitude (km)

Pressurembar

Clouds

• Passed through 3 clouds– Ascent– 1.02 to 1.14 km (3363 to 3763 feet)– 1.18 to 1.23 km (3863 to 4043 feet)

– Descent– 0.86 to 0.66 km (2837 to 2150 feet)

0 5 10 15 20 25 30 350

10

20

30

40

50

60

70

80

90

100

110Humidity vs Altitude

Humidity Ascent

Humidity Descent

Altitude (km)

Humidity (%rel)

Humidity Difference?

• 10% difference in humidity between ascent and descent

• 20 km mark on ascent and descent

• 1 km difference• 37.5 minute

difference

0 2 4 6 8 10 120

20

40

60

80

100

120

Humidity Information for the First/Last 11 km

Humidity First 10 km

Humidity Last 10 km

Altitude (km)

Humidity (%rel)

0 5 10 15 20 25 300

20

40

60

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100

120

NOAA Data Noon 5/24Humidity vs Altitude

Altitude (km)

Humidity (%rel)

0 5 10 15 20 25 30 350

100

200

300

400

500

600

700

f(x) = 0.00902191299 x³ + 0.043658215562 x² + 4.69312331995 x + 147.340553136R² = 0.997416409913255

Radius vs altitude

Altitude [km]

Radius[cm]