Aero 428, Spring '13

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Electromagnetic Sensing for Space- Borne Imaging
Aero 428, Spring '13

• In this course you will
• Study IR and Visible imaging systems that can be
  used to obtain high resolution imaging
• of space objects.
• Carry out design of a space system to find and
  image dangerous Near Earth Asteroids using
  stellar occultation
• Learn useful background on optics, telescopes,
  interferometry and imaging.
• Visit NASA Ames Research Center, Mission Design
  Center

Instructor Prof. D. C. Hyland Time MWF, 935
1050 Location Rm 204, HRBB
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Electromagnetic Sensing for Space-Borne Imaging
Lecture 1 Introduction

• Prof. David Hyland
• Department of Aerospace Engineering
• Dwight Look College of Engineering,
• Texas AM University

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Electromagnetic Sensing for Space-Bourne Imaging

• Study IR and Visible imaging systems that can be
  used to obtain high resolution imaging of space
  objects.
• To provide an example, consider design of a
  system to track and image Near Earth Asteroids
  using stellar occultation.
• Learn the needed background on optics,
  telescopes, interferometry and imaging.
• Get some hands-on knowledge via our existing two
  observatories.

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Electromagnetic Sensing for Space-Borne Imaging
Course output Mid-term exam March 5,
2013. Final Presentation at NASA Ames, April
22, 2013 Final Report due April 30, 2013
Instructor
Prof. D. C. Hyland Course Textbooks
Primary Space Mission Analysis and Design,
3rd Edition by Wiley J. Larson and James R.
Wertz Secondary Two-Dimensional Imaging, by R.
N. Bracewell, Prentice-Hall, 1995. Principles
of Optics, 7th Edition, by M. Born and E. Wolf,
Cambridge University Press, 1999.
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Course Outline
Phase I Lectures, homework, and group exercises
in class. Due to the need for instruction in much
new material, this phase covers the first seven
weeks of the semester. 1. Introduction to
Course and the Design Challenge 1/15 2.
Design Challenge Detecting and imaging Near
Earth Objects 1/17 3. Review of Maxwells
equations, EM wave propagation 1/22 4.
Geometric optics approximation Analysis of
lenses and mirrors 1/24 5. Survey of
monolithic telescope designs 1/29 6.
Telescope design light gathering, types of
aberrations, Strehl ratio 1/31 7. Fourier
optics Kirchoff integral, Huygens-Fresnel
principle 2/5 8. Telescopes revisited
Diffraction limits, PSF, MTF 2/7 9. Intro. to
sparse aperture systems Sparse primary
2/12 10. Interference phenomena, optical
coherence2/14 11. Mutual coherence, van
Cittert-Zernike theorem, image computation
2/19. 12. Survey of types of interferometry
and existing facilities. 2/21 13. Sources of
noise, classical to quantum 2/26 14. Noise
calculations for various detection methods
2/28 At the outset, the class will be
organized into Research Teams whose main purpose
is to help ones peers learn the lecture
material.
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Course Outline

• Reading assignments would be given out during
  class. Homework assignments will be given out
  each week concerning the previous weeks
  material. The assignments are given out each
  Thursday in class and are due the following
  Thursday in accordance with the following
  schedule
• HW 1 Out1/24, Due 1/31
• HW 2
  Out1/31, Due 2/7
• HW 3 Out2/7, Due 2/14
• HW 4 Out2/14, Due 2/21
• Each Thursday when an assignment is given out,
  one of the research teams will be asked to
  give a short presentation of the teams solution
  to one of the
• previous weeks homework problem.
• Mid-term exam March 5.
• Before Spring Break Class will be organized
  into Technical Specialty Teams
• and A Study Manager and Assistant Study
  Manager will be elected.

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Course Outline

• Phase II Beginning immediately after Spring
  Break - is the conceptual design phase for the
  design challenge using the technical research
  done in Phase I.
• The groups organized in Phase II will have five
  weeks to create a conceptual mission design.
• Special lectures can be given and/or groups can
  use class time to work together. Weekly meetings
  will be held for the class management team to
  brief the instructor on the project status.
• Final Presentation at NASA Ames
• The instructor will hold office hours and will
  serve an active role in working with students.
  The Final Report describing the conceptual design
  will be due on April 30, 2012.

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Course Outline
Grading Scheme Phase I (50) Homework 20 H
omework Presentations 5 Midterm
Exam 25 Phase II (50) Final
Review 25 Final Report 25 TOTAL
100
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MEASUREMENT OF PERFORMANCE
ATTITUDE Outstanding in enthusiasm Very
interested and industrious Average in diligence
and interest Somewhat indifferent Totally
uninterested WORKING WITH OTHERS Exceptionally
well accepted Works well in the group
setting Gets along satisfactorily Works mostly
alone Does not communicate DEPENDABILITY Can
be relied upon to follow through Above average
in dependability Usually dependable Sometimes
neglectful or careless Unreliable, can't be
counted on to follow through
QUANTITY OF WORK Worked
above and beyond the call of duty
Put out a full day's effort each
week Did reasonable amount of work Did less
work than expected Did hardly anything at
all QUALITY OF WORK Excellent, usable
work Very good Average Below average, much not
pertinent to project Poor ATTENDANCE AND
PUNCTUALITY Always present and on time Just an
occasional and excused absence Average in
attendance Often not there when needed,
frequently absent or late Unreachable
Note All activities should be consistent with
the Aggie Honor Code An Aggie does not lie,
cheat, or steal or tolerate those who do Please
refer to the Honor Council Rules and Procedures
on the web at http/www.tamu.edu/aggiehonor.
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Design Challenge

• Design a space, or ground-based system capable of
  tracking and profiling potentially dangerous
  Near-Earth Asteroids (NEAs) using stellar
  occultation
• Address the visible range of wavelengths (0.3 to
  0.9 ?m)
• Basic Objective initial identification and orbit
  determination
• Advanced Objective Resolve size and profile
  shape of select NEAs. Seek a design -
• That is most inexpensive
• That maximizes existing technology and hardware.
• We will be assisted by Roy Tucker, discoverer of
  hundreds of asteroids and co-discoverer of
  asteroid Apophis!

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Asteroid Tracking and Imaging via Stellar
Occultation
By recording the shadowing of the star at each
telescope and correlating the results, both the
orbital track and the asteroid profile can be
determined
Spatially distributed array of small telescopes
This telescope sees no star
Star is visible at this telescope
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3/31/2010
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Initial Results can be obtained from Existing
Two-telescope Facility

• One fixed and one mobile telescope. Both are 16
  in diameter. Observation process
• Point each telescope to the same star field
• Record the outputs of the photodetectors mounted
  in each telescope
• Watch for dips in intensity of each star
• Cross correlate stellar occultations across both
  telescopes
• Determine improved orbit estimate and size
  estimate

B
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3/31/2010
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Gigantic Astronomical Imaging array Array
Public Outreach/Learning Through Research

• This is a widely distributed network of
  observatories with two modes of operation
• Independent operation for educational purposes,
  and
• Collective operation for high resolution
  astronomy, including planet detection.

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GAIA - Basic Idea Public Outreach/Learning
Through Research

• Individual observatories on the Regional campuses
  of the TAMU system
• Field units can be operated from the member
  University campuses as well as schools (K-12),
  Colleges and other Universities in the region
• Field units could be operated as nodes of GAIA

• GAIA is an Intensity Interferometry Array
  (H.B.-T. effect See Appendix for details)
• Field units require only a telescope,
  photodectector, data acquisition and
  communication
• GAIA avoids the expense of new detector
  technology or amplitude interferometry
• Central Ops center would accomplish the image
  processing and Observatory operations

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Two Observatory Sites Are Now Operational