CCD Detection System for Rainbow Camera CCD readout system for specific lines of the CCD
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Transcript of CCD Detection System for Rainbow Camera CCD readout system for specific lines of the CCD
Earth Science Projects for Olin College Students:J. Vanderlei Martins UMBC Physics Department
and NASA GSFC Climate and Radiation Branch
1. CCD Detection System for Rainbow Camera– CCD readout system for specific lines of the CCD
2. CubeSat Sun-Sensor– CCD or CMOS based– Position Sensing Detector Based (
http://www.on-trak.com/theory.html)
– Solar Cell based
3. CubeSat Attitude Control System– Sun-Sensor to determine pointing– Magnetorquers to control the satellite’s attitude
Science – The Big Picture: Interaction Between Aerosols and Clouds
Andreae, et al. – Science 2004Smoking Rain Clouds over the Amazon
Cloud Droplet Measurements from Cloud Rainbow
F-M. Breon, P. Goloub, 1998.
Project 1- CCD Detection System for Rainbow Camera
• Interested in Only Selected lines of the CCD
• Most CCD/Cameras allow for windowing or binning but not for reading “a bunch” of selected lines along the CCD.
• Reading only selected lines increases speed and reduces data volume
Example of stripe filter: need to read only one line in the center of each stripe
Project 2 - CubeSat Sun-Sensor
• One face of the satellite must always point to the sun– maximizes solar incidence in the solar panel– Assures optimum geometry for cloud-side
measurements
• Feedback from Sun-Sensor increases accuracy of the Attitude and Determination Control System
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Reflectance Ratio 2.1/2.25mm
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Effective Radius (mm)
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Collision-Coalescence
Water-ice processes
Aerosol Impactin Microphysics?
water
mixed phase
ice
Ratio 2.1/2.25mm
Proxy for ice/waterseparation
Ratio 2.1/2.25mm
Proxy for ice/waterseparation
Temperature
ice
Water
More Science: Cloud-Side Profiling
Radiator face
Cloud CubeSatCloud CubeSatOrbit Geometry:Orbit Geometry:
Sun-Sensor
CMOS Detector Array
Ex: SunSensor from Nat. Cheng Kung University for the PACE CubeSat
Cloud-CubeSat
Other options:•PSD – analog position sensitive detector•Solar cell pyramid
Project 3 - CubeSat Attitude Control System
• Can we control the attitude of the satellite using Earth’s magnetic field
• How much torque is needed and how to implement an active control system to keep one face of the satellite always pointing to the sun.
• Sun-Sensor can be used as feedback mechanism
Mag
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oils
Use Sun-Sensor signal to align one face of the satellite (or solar panel) to
the sun