Rob Pettengill's presentation at the Texas Star Party in 2015 focuses on building a custom Raspberry Pi-based astronomy camera system, outlining the process, lessons learned, and future improvements. He emphasizes the benefits of combining small electronics with astronomy, including features like enhanced focusing and remote controlling of telescopes. The talk also highlights the challenges of wireless connectivity in astronomical imaging and suggests updates for enhancing image quality and operational efficiency.

1. Rob Pettengill - TSP 2015
The Astro Raspberry Pi Camera System 4
Rob Pettengill (rcp@alumni.stanford.edu)Rob PettengillRob Pettengill
Texas Star PartyTexas Star Party
16 May 2015
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Pie image from http://www.flickr.com/photos/rexroof/3802694376/
Creative Commons Attribution 3.0 Unported

2. Rob Pettengill - TSP 2015
AGENDA
• Why Build Your OwnWhy Build Your Own
Camera?
• How I Built Mine
• What I Learned
• What’s Next?
• Build Your Camera Not Mine
Christos Vasilas of Dash One
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1st afocal RPi Cam astro images

3. Rob Pettengill - TSP 2015
Internet Of Things And Astronomy
• Remote Observing downsized & updated.
• GoTo telescope control
• PushTo instrumentation and link to
planetarium software
• Automatic focusing.
• Guiding
• Camera control and enhancement.
• Plate solving.
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http://vaticanobservatory.org
http://simonbox.info/index.php/astronomy
http://www.recantha.co.uk/blog/?p=3615
http://astrobeano.blogspot.com/2014/01/instrumented-telescope-with-raspberry.html

4. Rob Pettengill - AASRob Pettengill - AAS 4
http://www.raspberrypi.org
http://beagleboard.org/Products/BeagleBone+Black
http://www.intel.com/content/www/us/en/do-it-yourself/edison.html

5. Rob Pettengill - AAS
W h a t Wa s I m p o r t a n t To M e ?
I wanted to combine my interests in small
electronics & Astronomy in a project.
• Saw potential in credit card sized
computers.
• Replace the laptop with a small low
power wireless computer. ARM based
IOT computers are powerful yet small
and low power.
• Replace the laptop display with a
wirelessly connected cell phone or iPad.
Better displays than many laptops and
far better than camera displays.
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Terry BeliaTerry Belia astrotex.com

6. Rob Pettengill - AAS
Why Build Your Own Camera?
• Sensor
• Customize to your scope and
target
• Functions
• Enhanced Focusing
• Region of Interest Crop
• Packaging
• Size & Weight
• Cooling
• Cost
• Fun
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7. Rob Pettengill - TSP 2015
R P i + C a m e r a M o d u l e +
Q u e s t a r C a m e r a A d a p t e r
C a n I t Wo r k ?
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https://www.flickr.com/photos/robpettengill/sets/72157635483690850/

8. Rob Pettengill - TSP 2015
Hang Me ’Til I’m Done
Astro RPi 2.0
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9. Rob Pettengill - TSP 2015
Screw Me Up Tight
Astro RPi 3.0
Uses a T-ring as a nut to bolt mounting plate for camera to theUses a T-ring as a nut to bolt mounting plate for
extension tubes
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10. Rob Pettengill - TSP 2015
A System Platform
Astro RPi 4.0
Uses simple metal cage for sensor board with a T-ring as a nut toUses simple metal cage for sensor board with a T-ring as a nut to
bolt
Uses simple metal cage for sensor board with a T-ring as a nut to
mounting plate to the telescope adapter.
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11. Rob Pettengill - TSP 2015
Sensor Board Mount Parts
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12. Rob Pettengill - TSP 2015
Assembled Sensor Cage & Telescope Adapter
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13. Rob Pettengill - TSP 2015
Assembled Sensor Cage & Telescope Adapter
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14. Rob Pettengill - TSP 2015
Acquisition Software Stack
IOT based model - smart devices, using web based
interfaces on the network, to talk to personal devices.
• On the Raspberry Pi
• Camera Interface (raspicam)
• Web Server - translate camera control from Web
requests to raspicam, serve up images for aiming and
focusing
• Image storage on local SD card
• Wireless ad hoc WiFi network for communication
• On a smartphone or tablet
• Web browser / Berrycam with camera control interface
• Last still image
• Streaming video
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15. Rob Pettengill - TSP 2015 15
72 image Astro Raspberry Pi Lunar Panorama made with Hugin
Rob Pettengill - TSP 2015Rob Pettengill - TSP 2015

16. Rob Pettengill - TSP 2015 16
BerryCam ready for Jupiter
imaging

17. Rob Pettengill - TSP 2015 17
Jupiter Io & Europa 240 of 500 images stacked & sharpened

18. Rob Pettengill - TSP 2015
Lessons Learned
• To ease switching from visual to sensor views, Prime focus sensor
should be located as close to parfocal with the eyepiece as possible.
• Wireless connection speeds limit ease of aiming and focussing.
Important features include:
• high speed wireless networks
• focus peaking
• region of interest cropping
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19. Rob Pettengill - TSP 2015
What's Next?
• Investigate larger sensors - Lack of Linux ARM drivers for high
quality imaging chips is a barrier for now. A few already provide
Intel Linux drivers and some ARM Linux (Point Grey).
• Improve ad hoc network speeds via faster wireless adapter or
feathered operation.
• Add region of interest cropping to focussing mode and image
capture mode.
• Add adjustable focus peaking display fo focussing mode.
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20. Rob Pettengill - TSP 2015
Extra Slides On ImageExtra Slides On Image
Evaluation
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21. Rob Pettengill - TSP 2015
Quick Resolution Check
• Calculate angular
pixel size
• Down-sample image
to reference
resolutions
• Up-sample reference
images to original
size
• Compare original to
reference images
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22. Rob Pettengill - TSP 2015
• Down-sample a reference image to the desired resolution
• Up-sample reference images match your own image
• Compare your original to reference images
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Comparative Resolution
Check
• Find HQ Reference
• Calculate angular pixel
resolution sizes