DINO Peer Review10 December 2003 Science Jessica Pipis Dohy Faied Paul Kolesnikoff Brian Taylor Miranda Mesloh David Goluskin

DINO Peer Review 5 December 2015 Introduction The purpose of the science subsystem is to take stereoscopic images of clouds in order to create a topographic map of cloud heights. There will be two camera’s mounted at specific angles on the satellite. The gathered images will be sent to the flight computer where an algorithm will find matching points. Using these points the images will be overlaid creating a topographic map which will be sent back to CU. Also included is a description of an algorithm and test plan.

DINO Peer Review 5 December 2015 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 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

DINO Peer Review 5 December 2015 Requirements Mass 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

DINO Peer Review 5 December 2015 Block Diagram Camera #1Camera #2 C&DH USB

DINO Peer Review 5 December 2015 The Camera Basic Information –Olympus C 4000 –Has C-mount capabilities –Field of view depends on lens –4.0 megapixel camera –Has USB port for data output –Maximum resolution of 3200x2400 Does appear raw data is not available Has TIFF format –Advanced noise filter Need to see if this can be disabled –Electric variable shutter speed 1/1000 to 16 second

DINO Peer Review 5 December 2015 Needed Flight Preparations Design interface for camera –USB or Flash with USB Write software for camera Make or acquire lens meeting NASA requirements Design mount for camera Test

DINO Peer Review 5 December 2015 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

DINO Peer Review 5 December 2015 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 –Time

DINO Peer Review 5 December 2015 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

DINO Peer Review 5 December 2015 Influences Based on: Altitude km Velocity – 7.65 km/s

DINO Peer Review 5 December 2015 Simulator Used to simulate topography of the ground produced by stereoscopic sensing Influenced by factors above Atmosphere “magnifies” results

DINO Peer Review 5 December 2015 Results

DINO Peer Review 5 December 2015 Optimization of Stereo Pairs Between 10 o and 20 o (probably around 15 o ) Two camera layout, preferably three –Multiple pictures Determining along and cross track wind Large field of view Multiple layouts of camera 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 –

DINO Peer Review 5 December 2015 Camera Layout With Nadir

DINO Peer Review 5 December 2015 Error in Camera Layout 10 o Nadir 30 o 20 o

DINO Peer Review 5 December 2015 Error in Camera Layout The angle between two cameras is insignificant in camera layout Error increases as angle between nadir and a camera increases Error negatively affects algorithm Suggests a +/- camera angle better than nadir and forward looking -10 o +10 o

DINO Peer Review 5 December 2015 Camera Layout Third camera preferable to normalize +/- camera views Can obtain nadir camera view with –Two cameras –Multiple pictures –Large field of view (dependant on number of pictures taken) Can have lower resolution in vertical direction

DINO Peer Review 5 December 2015 Example Given –Two cameras –Field of view of 10 o Time –About 4.88 seconds between pictures –Illumination changes and cloud movement becomes insignificant Covers nadir and fore/aft views Angle between fore/aft views of 15 o

DINO Peer Review 5 December 2015 Algorithm Needs Two Images Ground Reference Point Cloud Camera Ground Reference Point Cloud Ground Reference Point Cloud Camera Ground Reference Point Cloud First Satellite PositionSecond Satellite Position First Cloud ImageSecond Cloud Image

DINO Peer Review 5 December 2015 Algorithm Combines Two Images Cloud #1 Ground Reference Points Cloud #2 First Images are Overlaid 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 Cloud #1Cloud #2 Images are Transformed to Align at Ground Level Ground Reference Points Cloud #1 Ground Reference Points Cloud #2 Images are Shifted Until Features Match

DINO Peer Review 5 December 2015 DINO Moves in Three Axes Pitch Φ Yaw  Roll Ψ Direction of Flight ±10° Pointing Accuracy ±2° Position Knowledge 90 min Oscillation Period

DINO Peer Review 5 December 2015 Pointing Error Moves Two Images Cloud #1 Ground Reference Points Cloud #2 Yaw Rotated Image Pair Yaw Rotation is Greatest Error Forward Image has Rotation and Translation with Yaw Error Field of View Must be Large Enough to Accommodate Motion Ground Reference Points Cloud #1Cloud #2 No Error Image Pair

DINO Peer Review 5 December 2015 Modeling Motion Errors Forward Camera CorrectionYaw Error Model Roll Error ModelPitch Error Model

DINO Peer Review 5 December 2015 Science Algorithm is Under Way Basic Algorithm Determined Floating Point Math Avoided Topo Map in Pixel Distance Saves Bandwidth Point Matching needs Work Finalizing Motion Correction Technique Pseudo-Code Needed Testing Needed Final Write-up Needed Implementation in Software not started

DINO Peer Review 5 December 2015 Science Subsystem Test Plan 1.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

DINO Peer Review 5 December 2015 Science Subsystem Test Plan 2.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

DINO Peer Review 5 December 2015 LEGO Table Test Plan Flat Surface can be Mounted on Gimbal to Test Picture Angles Variety of Heights and Configurations can be Tested Ideal for Illumination Effects and Color Recognition Check for donation from LEGO

DINO Peer Review 5 December 2015 Commands and Sensors Commands from C&DH –Set up cameras –Turn on/off camera #1 – Turn on/off camera #2 –Take a picture –Retrieve pictures –Clear memory Sensors –Possible Thermistor

DINO Peer Review 5 December 2015 Parts List 2 Camera’s - Approx. $499 each –Olympus C megapixel USB Cables PC Board Multiplexer Components LEGO table and testing components

DINO Peer Review 5 December 2015 Decisions Not Yet Made Camera angle on structure –Time between pictures Yaw control needed How many pictures are needed to determine along track wind What is the time delay between images

DINO Peer Review 5 December 2015 Issues and Concerns Camera –Problem The camera we are currently using doesn’t have software for USB –Solution We can write our own software for USB or design an interface to the flash card Determining Camera angles –Depends on algorithm used Determining when is a good time to take pictures –Determining whether it is a good picture We can generate topographic maps, but they may be cloudless scenes Probably will use color information Time between pictures –Time we have to take pictures vs. time we need to take pictures

DINO Peer Review 5 December 2015 Questions?