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Electric Breakdown Voltage

Electric Breakdown Voltage. Chris Rowan | Anthony Thompson | Philip de la Vergne | Aaron Wascom | Brandon Sciortino. http:// www.scienceclarified.com/Di-El/Electric-Arc.html. Mission Goal.

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Electric Breakdown Voltage

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  1. Electric Breakdown Voltage Chris Rowan | Anthony Thompson | Philip de la Vergne | Aaron Wascom | Brandon Sciortino http://www.scienceclarified.com/Di-El/Electric-Arc.html

  2. 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

  3. 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

  4. Technical Objective • At the conclusion of our flight, our payload will have stored data during flight on: • Pressure • Temperature • Humidity • Time • Voltage across the spark gap • Currents across the spark gap indicating an electrical breakdown

  5. 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

  6. 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

  7. 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

  8. 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.

  9. Science Background: Avalanche Effect Cont.

  10. Science Background: Paschen’s Curve 30k 20k Voltage 10k Pressure 100k 50k 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

  11. 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

  12. 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

  13. 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

  14. 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 management • DC to HV DC converter • Ammeter Design

  15. 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

  16. Payload Design: System Design

  17. 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

  18. 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

  19. Payload Design: Mass Management

  20. Payload Design: Power Budget

  21. 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

  22. Project Management: Organization

  23. Project Management: Master Schedule

  24. Spectral Analysis By: Chris Rowan Anthony Thompson Philip de la Vergne Aaron Wascom Brandon Sciortino

  25. Mission Goal • This 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

  26. Science Objectives • Identify different topography features flown over during flight to establish ground truth • Collect and record images at high altitude • Compare 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

  27. Technical Objectives • Measure the reflectance properties of various terrains • Successfully launch an optical sensor payload • Determine location of the payload in relationship to the launch point and the ground with GPS • Extract, process, and analyze data stored on the payload

  28. Science Background Remote 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

  29. Science Background Active vs. Passive Active • Beam artificially produced energy to a target and record the reflected component Passive • Detect only energy emanating naturally from an object http://www.intechopen.com/books/biomass-and-remote-sensing-of-biomass/introduction-to-remote-sensing-of-biomass

  30. Science Background Infrared • Light with longer wavelengths than visible light • Extending from the red edge of the visible spectrum http://gers.uprm.edu/geol6225/pdfs/06_thermal_rs.pdf

  31. Science Background Spectral 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

  32. Science Background Characteristics 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

  33. Science Background Characteristics of Terrain Water • Longer 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.

  34. Science Background Characteristics of Terrain Vegetation • Chlorophyll 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

  35. Science Background Characteristics of Terrain Soil • They tend to have high reflectance in all bands • Dependent on factors such as the color, constituents, and moisture content

  36. Science Background Spectral Signature http://remote-sensing.net/concepts.html

  37. Science Background Spatial 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

  38. Science Background Angular 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-calculator

  39. Science Background Instantaneous Field of View • The 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. http://www.crisp.nus.edu.sg/~research/tutorial/image.htm#ifov

  40. Science Background Instantaneous Field of View • the angular cone of visibility of the sensor • the area on the Earth's surface which is "seen" from a given altitude • The size of the area viewed is determined by multiplying the IFOV by the distance from the ground to the sensor

  41. Science Background Pixels • A digital image comprises of a two dimensional array of individual picture elements • Each pixel represents an area on the Earth's surface. • IntensityValue • Location Address

  42. Science Background Pixels Intensity Value • The 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

  43. Science Background Pixels Location Address • Denoted 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

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

  45. Science Background Filters • Filters are used to zone in on portion of the EM Spectrum • There are two types of filters • Lens filters • Image processing filters

  46. Science Background Filters Lens Filter • Applied directly to the remote sensor to only capture selected portions of the spectrum Band-Pass filter selecting a specified wavelength

  47. Science Background Filter Processing Filters • Applied during post processing to zone in on specific intensities Band-Pass filter selection of a specified intensity

  48. Science Background Filter Processing Filters • Low-Pass – removes high data points • High-Pass – removes low data points • Band-Pass – keeps all data within a specified band • Band-Reject – removes all data within a specified band

  49. Additional Uses • Determining the health of specific vegetation • Identifying specific types of vegetation through the analysationof their specified emittance • Law Enforcement can locate illegal plant growth such as the Cannabis plants

  50. Requirements • The camera must cover near infrared • The camera shall be at a 0° angle with respect to the payload • The camera must be the lowest payload on the launch, to avoid camera obstructions • The 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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