1. William “Lee” Willcockson
Science Team
Paul Kolesnikoff
William “Lee” Willcockson
Miranda Mesloh
Pascal Getreuer
Keith Wayman
Casey Rubin
Ariel Esposito
Science
Jessica Pipis
Mike Wong
Allyson Bieryla
Anders Fornberg
Introduction
The purpose of the science subsystem is to take stereoscopic images of clouds in order to create a topographic map from which we can determine cloud heights.
There will be two camera’s mounted at specific angles on the satellite.
Each camera will take an image that will contain at least one identifiable cloud feature and at least one identifiable ground feature.
These images will then be sent to the flight computer where they will be overlapped and turned into a topographic map which will allow us to determine the height of the clouds.
Requirements
The Science subsystem shall be designed to meet all of DINO’s science objectives. It shall implement a stereoscopic imaging technique in order to measure cloud heights.
Clouds imaged in the visible spectrum
Field of view of degrees.
Resolution of better than 640x480
Shutter speed of 1/64th of a second or faster
Ample amount of time shall be allotted for the software system to finish processing an image before another image is required
Each image shall contain at least one identifiable cloud feature and at least one identifiable ground feature
Each of the multiple images used to produce a topographic map of the cloud features must contain the same cloud features and the same ground features
Requirements-cont.
Mass kg on the main satellite
Power- less than 11 Watts on the main satellite
The Science subsystem shall operate on 5V and/or 12V lines
All Science subsystem components shall comply with NASA’s safety requirements
There shall be no pressurized vessels in the science subsystem, including the lens of each camera
All components shall comply with NASA’s outgassing specifications
Any glass components shall comply with NASA’s regulations
All components shall either be contained or meet NASA’s requirements to be a low-released mass part
Block Diagram
The Camera
Basic Information
AIPTEK Pen Cam 1.3 Mega
41.5 degree field of view
Maximum resolution of 1248x960
Electric variable shutter speed
Needs 5 Volt line to each camera
At maximum resolution, each picture is about 200K.
Takes about seconds for each picture to store.
Takes a couple minutes to retrieve pictures.
Time is dependent on software.
Needed Flight Preparations
Replace current lens with Jam Cam lens.
Remove springs on circuit board.
Conformal coat entire board.
Build another casing for Jam Cam lens.
Make sure that lens is bolted securely to circuit board.
Decisions Not Yet Made
Camera angle on structure
Time between pictures
Yaw control needed
How to determine when to take pictures
Determining if it is a good picture
Commands and Sensors
Commands from C&DH
Turn on/off camera #1
Turn on/off camera #2
Take a picture
Retrieve pictures
Clear memory
Sensors
Possible Thermistor
Parts List
2 Camera’s - Approx. $60 each
USB Cables
PC Board
Multiplexer Components
Test Plans
Find a camera that will work
Make sure that components are flyable
Do STK simulations
Test with C&DH to make sure commands work
Create a stand alone test that tests the cameras ability to respond to commands without C&DH.
Vibration testing to make sure lens will not break (not fracture critical)
Issues and Concerns
Camera
Problem
The camera that we are currently using has a lens casing that is made of what looks to be ABS manufactured plastic.
Solution
Using a Jam Cam lens instead of the lens that came with the camera.
We will need a new lens mount built to fit the jam cam lens.
Field of view and resolution will need to be recalculated.
Different focal length may cause problem with images
Acceptable amount?
Determining Camera angles
Depends on optical power of camera
An acceptable amount of error
Determining when is a good time to take pictures
Determining whether it is a good picture
We are going to need to talk with software to see how this is going to work.
Time we have to take pictures vs. time we need to take pictures
Find USB commands

2. DINO Science
The science subsystem takes stereoscopic images of clouds and processes them to create a topographic map of cloud heights.
Colorado Space Grant
Consortium

3. Introduction
The science subsystem takes stereoscopic images of clouds and processes them to create a topographic map of cloud heights.
The two cameras will be mounted to look forward and aft at +/-7.5deg from Nadir on the satellite.
The two images will be timed to photograph the same object.
The two images will be sent to the flight computer where an algorithm will create a topographic map.
The algorithm and test plan are also covered.
Colorado Space Grant
Consortium

4. Science Hardware Block Diagram
Camera #1
Camera #2
Digital IO
Microcontroller
RS-232
C&DH
USB
USB
Colorado Space Grant
Consortium

5. Science Algorithm Flow Chart
Find Cloud
Take
Forward Picture
Take
Aft Picture
Linearize
Pictures
Find
Matching Pixels
Generate
Topo Map
Colorado Space Grant
Consortium

6. Changes Since PDR Camera: Canon Digital Rebel
Field of View: 28 degrees
Use Microcontroller for Digital IO
Weight Budget Increased to 1.75kg
Colorado Space Grant
Consortium

7. Functional Requirements
Structure
Software
Stereo Imaging
Estimate Cloud Height
Capture Image of Cloud
Comm. With Camera/Computer
Camera
Testing
Algorithm
Colorado Space Grant
Consortium

8. Requirements
The Science subsystem shall be designed to meet all of DINO’s science objectives. It will implement a stereoscopic imaging technique in order to measure cloud heights.
Clouds imaged in the visible spectrum
Field of view of 28 degrees is needed for cameras.
Cameras will have a resolution of better than 640x480.
Shutter speed of 1/64th of a second or faster
Ample amount of time shall be allotted for the software system to finish processing an image before another image is required
Each of the multiple images used to produce a topographic map of the cloud must contain the same features
Colorado Space Grant
Consortium

9. Requirements Mass- 1.75 kg on the main satellite
Power- less than 11 Watts on the main satellite
The Science subsystem will operate on 5V and/or 12V lines
All Science subsystem components shall comply with NASA’s safety requirements
There shall be no pressurized vessels in the science subsystem, including the lens of each camera
All components will comply with NASA’s outgassing specifications
Any glass components shall comply with NASA’s regulations
All components shall either be contained or meet NASA’s requirements to be a low-released mass part
Colorado Space Grant
Consortium

10. Camera Mounting System
Colorado Space Grant
Consortium

11. Science System Schematic
Colorado Space Grant
Consortium

12. The Camera Cannon Digital Rebel Dimensions (W x H x D):
142 x 99 x 72.9 mm
Weight: 750 g
Power Requirements:
7.4 volts
Cost: $1300 Including Lens
Thermal Requirements:
0 - 40°C
Colorado Space Grant
Consortium

13. Algorithm Needs Two Images
Camera
Camera
Cloud
Cloud
Ground Reference Point
Ground Reference Point
First Satellite Position
Second Satellite Position
Cloud
Cloud
Ground Reference Point
Ground Reference Point
First Cloud Image
Second Cloud Image
Colorado Space Grant
Consortium

14. Algorithm Combines Two Images
Cloud #1
Cloud #2
Cloud #1
Cloud #2
Ground Reference Points
Ground Reference Points
First Images are Overlaid
Images are Transformed to Align at Ground Level
Cloud #1
Cloud #2
Horizontal Separation Between Matching Point on Images Determines Height
Topo Map of Point Separation Allows Integer Math
Point Matching Algorithm in Progress
Use of Color and Derivative Information Likely
Ground Reference Points
Images are Shifted Until Features Match
Colorado Space Grant
Consortium

15. DINO Moves in Three Axes
Yaw 
±10° Pointing Accuracy
±2° Position Knowledge
90 min Oscillation Period
Roll Ψ
Direction of
Flight
Pitch Φ
Colorado Space Grant
Consortium

16. Pointing Error Moves Two Images
Cloud #1
Cloud #2
Ground Reference Points
Yaw Rotation is Greatest Error
Forward Image has Rotation and Translation with Yaw Error
Field of View Must be Large Enough to Accommodate Motion
No Error Image Pair
Cloud #1
Cloud #2
Ground Reference Points
Yaw Rotated Image Pair
Colorado Space Grant
Consortium

17. Modeling Motion Errors
Forward Camera Correction
Yaw Error Model
Pitch Error Model
Roll Error Model
Colorado Space Grant
Consortium

18. Science Algorithm is Under Way
Basic Algorithm Determined
Floating Point Math Avoided
Topo Map in Pixel Distance Saves Bandwidth
Point Matching Correlation
Finalizing Motion Correction Technique
Testing Needed
Final Write-up Needed
Implementation in Software not started
Testing Cloud Detection Algorithm
Colorado Space Grant
Consortium

19. Camera Angles Factors influencing camera angle selection
Base/height ratio
Algorithm matching
Illumination
Signal to noise ratio
Larger camera angles mean smaller ratio
Time
Movement of clouds
Camera Delays
Colorado Space Grant
Consortium

20. Influences Base/Height Ratio
Error caused by optical system is unchanging
Larger ratio decreases relative error
Largest camera angle desired
Illumination
Differences increase with camera angle
By change in relative position of cloud, satellite, and sun
Cloud position and Illumination change over Time
Colorado Space Grant
Consortium

21. Influences Signal/Noise Ratio Decreases with camera angle
Large ratio desired for increased accuracy of determining cloud height from stereo pairs
Cloud Movement
Increases with camera angle
Affects algorithm’s ability to successfully match points in stereo pair
Smaller camera angle is preferred
Colorado Space Grant
Consortium

22. Influences Based on: Altitude - 425 km Velocity – 7.65 km/s
Colorado Space Grant
Consortium

23. Simulator
Used to simulate topography of the ground produced by stereoscopic sensing
Influenced by factors above
Atmosphere “magnifies” results
Colorado Space Grant
Consortium

24. Results
Colorado Space Grant
Consortium

25. Optimization of Stereo Pairs
Between 15o (+/-7.5o)
Two camera layout
Multiple pictures
Determining along and cross track wind
Large field of view
Previous tables and graphs obtained from
Boerner, Anko: The Optimisation of the Stereo Angle of CCD-Line-Scanners, ISPRS Vol. XXXI, Part B1, Commission I, pp , Vienna 1996
Colorado Space Grant
Consortium

26. Test and Build Facilities
Final Test in Clean Room
Collaborates all systems for final check
Camera Ops
Finding Cloud
Data Download
Algorithm
Nadir
Forward
Colorado Space Grant
Consortium

27. Ground Support Lego Test Bed
=Jam Cam
Lego Test Bed
Yaw 
Color of arrow corresponds with movement of table piece.
Roll Ψ
Purpose: To test accuracy of algorithm using known heights of stacked Lego pieces at different angles to simulate pictures in flight.
Direction of
Flight
Pitch Φ
Colorado Space Grant
Consortium

28. Documentation Design Overview Testing Algorithm Disassembly/Assembly
Technical manual
Testing
Outline for first two weeks of camera and entire system
Detailed document including testing results
Algorithm
Outline of how and why it works
Disassembly/Assembly
Outline of procedures to disassemble/assemble camera
Trade Studies
Selection of Camera
Microcontroller
Colorado Space Grant
Consortium

29. Science Subsystem Test Plan
Camera Operation
a. Set – up:
i. Iris (f-stop)
ii. Shutter Speed
iii. Flash Setting
iv. Focus
v. Picture type (Mode)
b. Acquisition
i. Shutter Command
ii. Accuracy
Colorado Space Grant
Consortium

30. Science Subsystem Test Plan
Algorithm
a. Individual Pictures
i. Find Cloud
ii. Find Features
b. Picture Sets
i. Transform to Same Coordinate
ii. Match Reference Features
iii. Correlate All Features
iv. Generate Contours
Colorado Space Grant
Consortium

31. DINO Science Schedule Algorithm Development Camera Preparation
Finalize Coordinate Transformations 20 March
Linearization (Scaling) Integration 20 March
Pixel Correlation Routine 15 April
Topo Line Generation Routine 1 May
Compression Format 1 May
Camera Preparation
Disassembly and Procedure 20 March
Digital Control April
Integrated and Tested 1 May
Colorado Space Grant
Consortium

32. Parts List 2 Camera’s - Approx. $1300 each USB Cables PC Board
Canon Digital Rebel
USB Cables
PC Board
Microcontroller Components
Colorado Space Grant
Consortium

33. Questions?
Colorado Space Grant
Consortium