Electric Breakdown Voltage

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Electric Breakdown

Voltage

Chris Rowan | Anthony Thompson | Philip de la Vergne | Aaron Wascom | Brandon Sciortino

http://www.scienceclarified.com/Di-El/Electric-Arc.html



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Mission Goal The goal of this

payload is to understand the relationship of temperature and humidity on electric breakdown voltage.

http://commons.wikimedia.org/wiki/File:Paschen_Curves.PNG

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Science Objectives Recreate as closely as possible Paschen’s curve

using a corona discharge

Deviations from Paschen’s curve will be used to understand the relation of temperature and humidity on the minimum breakdown voltage

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Technical Objective At the conclusion of our flight, our payload will

have stored data during flight on:o Pressureo Temperatureo Humidityo Timeo Voltage across the spark gapo Currents across the spark gap indicating an electrical

breakdown

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Science Background: Terms Corona Discharge: An electrical discharge due to

ionization of the fluid around a conductor

Spark Gap: A space between two high-potential terminals (as of an induction coil or spark plug) through which pass discharges of electricity

Electric Potential: The maximum amount of energy which can be exerted by each unit of charge in the conductor that is experiencing a force due to an electric field

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Science Background: Corona Current

Electric breakdown will be determined by magnitudes of current across the spark gap

Current carried by corona discharge is an integral of the current density over the surface of the conductor

Current carried by corona discharge is measured in microamperes

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Science Background: Discharge Mechanism

Coronal discharges are a result of chain reactions in which neutral atoms are ionized by high energy particles in the atmosphere.

When neutral atoms are ionized they release free electrons which then feel coulomb forces due to the electric field.

The positively and negatively charged particles are accelerated in opposite directions and given a kinetic energy

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Science Background: Avalanche Effect

The chain reactions are commonly called electron avalanches because as the kinetic energy in free electrons in the field increase they gain the ability to ionize other neutral atoms they collide with.

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Science Background: Avalanche Effect Cont.

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Science Background: Paschen’s Curve

This data graph can be used as a way to predict the voltage values, while neglecting temperature, humidity, and air ionization, which are needed to successfully discharge across a spark gap

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Volta

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50k

100kPressure

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Power Requirements DC/DC converter shall provide a voltage capable

of creating an electrical breakdown across the spark gap throughout the flight

Spark gap will be set to a distance allowing for an electrical breakdown to occur throughout the flight within the power and structural constraints

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Data Requirements Accurately timestamp the ambient pressure, temperature, and

humidity around the payload.

Accurately timestamp the times in which a current indicating electrical breakdown occurs

Data will be collected at a time interval that will observe all incremental changes in breakdown voltage

Data collected shall be stored by an archive system capable of being extracted, processed, and analyzed at the conclusion of the flight

Ammeter shall be accurate to the microampere

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Structure Requirements The payload will remain fully functional during the

thermal, vacuum, and shock preflight tests

The payload will have one face with two 17 cm holes cut for the LaACES interface

The payload shall not weigh more than 500g

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Payload Design Parts are readily available at a reasonable price

Mass and size of the parts are within the constraints of the payload interface set LaACES managemento DC to HV DC convertero Ammeter Design

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Payload Design: Principle of Operation

The analog signals from the sensors will be conditioned before entering the Analog-Digital converter and stored to the EEPROM via the Basic Stamp

The BalloonSat shall control the voltage amplification of the DC/DC converter via the Digital-Analog converter

The BalloonSat shall store true binary values for current to the EEPROM indicating an electrical breakdown

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Payload Design: System Design

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Payload Design: Mechanical External Design

The payload will have dimensions of 17 cm x 10 cm x 10 cm

At least ¾ inch wall thickness

The 17 cm holes will be on the 17 cm face and through the payload walls

The top face will have a lid for access

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Payload Design: Mechanical Internal Design

Each part will be attached to two walls for stability during flight and landing

Cables will be as direct as possible to prevent cables acting as antennae

The spark device will be in an individual compartment with holes for ventilation

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Payload Design: Mass Management

Part Weight Uncertainty

Payload Interfacing 65g +/-15

BalloonSat 70g +/-5

Power Source 100g +/-50

Payload Casing 60g +/-20

DC to HV DCConverter

30g +/- 20

Ammeter 40g +/- 15

Total 365g +/- 125g

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Payload Design: Power BudgetCurrent Power

mA(4*h)

DC to HV DC Converter

250 mA MAX 1000mAh

BalloonSat 60 mA 240mAh

Payload Interface 36 mA 144mAh

Total 346 mA 1384 mAh

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Project Management All documents will follow version control as stated

in team contract

Project Manager coordinates functional groups

Team meetings at least 3 times a week

Deadlines for incremental tasks set

Risk Management

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Project Management: OrganizationResponsibility Team MemberProject Leader Anthony ThompsonDocumentation Chris Rowan

Mechanical Engineer Anthony Thompson

Electrical Engineer Philip de la Vergne

Software Developer Aaron Wascom

Calibration Brandon SciortinoElectronics Philip de la VergneIntegration Chris Rowan

Data Processing Anthony ThompsonAnalysis Chris RowanTesting Brandon Sciortino

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Project Management: Master Schedule

Spectral Analysis By:

Chris RowanAnthony ThompsonPhilip de la Vergne

Aaron WascomBrandon Sciortino

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Mission GoalThis LaACES payload will measure spectral

signatures emitted over a wide spectrum of terrains with the use of remote sensing, more specifically infrared.

http://www.intechopen.com/books/biomass-and-remote-sensing-of-biomass/introduction-to-remote-sensing-of-biomass 25

http://www.intechopen.com/books/biomass-and-remote-sensing-of-biomass/introduction-to-remote-sensing-of-biomass

Science ObjectivesIdentify different topography features flown over

during flight to establish ground truthCollect and record images at high altitudeCompare and contrast infrared images of the

topography with other remote sensing sources and Team Chosen

Determine the latitude, longitude, and altitude of each image location

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Technical ObjectivesMeasure the reflectance properties of various

terrains Successfully launch an optical sensor payloadDetermine location of the payload in relationship

to the launch point and the ground with GPSExtract, process, and analyze data stored on the

payload

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Science BackgroundRemote Sensing

Acquisition of information about an object or phenomenon without making physical contact

Use of aerial sensor technologies to detect and classify objects on Earth by means of propagated signals

Photographic cameras, mechanical scanners, and imaging radar systems

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Science BackgroundActive vs. Passive

ActiveBeam artificially produced energy to a target

and record the reflected component PassiveDetect only energy emanating naturally from an

object

http://www.intechopen.com/books/biomass-and-remote-sensing-of-biomass/introduction-to-remote-sensing-of-biomass29


Science BackgroundInfrared

Light with longer wavelengths than visible lightExtending from the red edge of the visible

spectrum

http://gers.uprm.edu/geol6225/pdfs/06_thermal_rs.pdf

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Science BackgroundSpectral Signature

The ratio of reflected energy to incident energy as a function of wavelength

Various materials of the earth’s surface have different spectral reflectance characteristics

The spectral reflectance is dependent on wavelength; moreover, it has different values at different wavelengths for a given terrain feature

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Science BackgroundCharacteristics of Terrain

Reflected energy from an object can be measured, and a spectral signature can be formed

By comparing the response pattern of different features, distinctions between them can be made

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WaterLonger wavelength in visible and near infrared

radiation is absorbed more by water than shorter visible wavelengths

Typically looks blue or blue-green due to stronger reflectance at these shorter wavelengths, and darker if viewed at red or near infrared wavelengths.

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VegetationChlorophyll strongly absorbs radiation in the red

and blue wavelengths but reflects green wavelengths

The internal structure of healthy leaves act as excellent diffuse reflectors of near-infrared wavelengths

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SoilThey tend to have high reflectance in all bandsDependent on factors such as the color,

constituents, and moisture content

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Science BackgroundSpectral Signature

http://remote-sensing.net/concepts.html 36

Science BackgroundSpatial Resolution

The spatial resolution, also known as ground resolution, is the ground area imaged for the instantaneous field of view (IFOV) of the sensing device

Spatial resolution may also be described as the ground surface area that forms one pixel in the camera image

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Science BackgroundAngular Field of View

The field-of-view (FOV) is the range of angles from which the incident radiation can be collected by the detector

Spatial resolution of passive sensors depends primarily on their Instantaneous Field of View (IFOV)

http://www.supercircuits.com/resources/tools/lens-calculator38

Science BackgroundThe smallest detail that

you can get an accurate temperature measurement upon at a set distance

The signal recorded by a detector element is proportional to the total radiation collected within its IFOV.

Instantaneous Field of View

http://www.crisp.nus.edu.sg/~research/tutorial/image.htm#ifov 39

Science BackgroundA. the angular cone of

visibility of the sensor B. the area on the Earth's

surface which is "seen" from a given altitude

C. The size of the area viewed is determined by multiplying the IFOV by the distance from the ground to the

sensor Instantaneous Field of View

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Science BackgroundPixels

A digital image comprises of a two dimensional array of individual picture elements

Each pixel represents an area on the Earth's surface.

1. Intensity Value 2. Location Address

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Intensity ValueThe measured physical quantity such as the

solar radiance in a given wavelength band reflected from the ground

This value is normally the average value for the whole ground area covered by the pixel

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Location AddressDenoted by its row and column coordinates in

the two-dimensional image. In order to be useful, the exact geographical

location of each pixel on the ground must be derivable from its row and column

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Science BackgroundFilters

Filters are used to zone in on portion of the EM Spectrum

There are two types of filters1. Lens filters 2. Image processing filters

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Science BackgroundFilters

Lens FilterApplied directly to the remote sensor to only

capture selected portions of the spectrum

Band-Pass filter selecting a specified wavelength

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Science BackgroundFilter

Processing FiltersApplied during post processing to zone in on

specific intensities

Band-Pass filter selection of a specified intensity

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Science BackgroundFilter

Processing FiltersLow-Pass – removes high data pointsHigh-Pass – removes low data pointsBand-Pass – keeps all data within a specified bandBand-Reject – removes all data within a specified

band

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Additional Uses Determining the health of specific vegetationIdentifying specific types of vegetation through

the analysation of their specified emittanceLaw Enforcement can locate illegal plant growth

such as the Cannabis plants

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RequirementsThe camera must cover near infraredThe camera shall be at a 0° angle with respect to the

payloadThe camera must be the lowest payload on the

launch, to avoid camera obstructionsThe camera shall provide a pixel and spatial

resolution falling within the suitable scope for long-range photography

Camera must be capable of zooming at various rates during different points of the flight to compensate for altitude changes

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RequirementsThe remote sensing must be equipped with a

proper filter lens that records near infraredPictures will be taken at the highest rate

possible before resolution becomes no goodAdequate amount of storage on board to store

photosThe timestamp on the BalloonSat must match

the timestamp on the GPS locaterA timestamp will be recorded on each

photograph

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RequirementsThe payload shall remain fully functional during

the thermal, vacuum, and shock preflight testsThe payload will have two holes 17 cm apart for

the LaACES interfacingThe payload will have a mass of less than 500

grams

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RequirementsDeadlines

A Pre-PDR shall be completed by January 15, 2013

A PDR document shall be completed by February 5, 2013

A Pre-CDR shall be completed by March 5, 2013A CDR document shall be completed March 26,

2013An FRR document shall be completed by April

30, 2013

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Payload DesignPrinciple of Operation

An infrared camera will capture images of the ground during the duration of flight

Filters will be applied during flight and post flight in order to analyze and determine each topographic feature captured

The BalloonSat will control the camera’s zoom and capture rate

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Payload DesignSystem Design

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Payload DesignMechanical Design

Infrared camera positioned 0 degrees with respected to the payloadPoints directly at the ground

The camera must be at the bottom of the payloadClear view of the ground

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Payload Design: Mass Management

Part Weight Uncertainty

Camera 150g +/-50

BalloonSat 70g +/-5

Power Source 70g +/-35

Payload Casing 60g +/-30

Total 380g +/- 120

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Payload Design: Power Budget

Sensors Current PowermA*(4h)

BalloonSat 60 mA 240 mAh

Camera 440 mA 1760 mAh

Total 500 mA 2000 mAh

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Project Management All documents will follow version control as stated

in team contract

Project Manager coordinates functional groups

Team meetings at least 3 times a week

Deadlines for incremental tasks set

Risk Management

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Master Schedule

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Electric Breakdown Voltage

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