NVO and The Digital Planetarium

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NVO and The Digital Planetarium
NVO Outreach Workshop
July 11, 2002

• Ed Lantz
• Product Development manager
• Spitz, Inc.

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Dome Theaters
Traditional Planetarium
Large-FormatFilm Theatre
Digital Planetarium
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Traditional Planetaria

• Hemispheric Projection Screen
• Starfield Projector
• High-resolution astronomical simulation
• Hemispheric Slide Projection or All Skys
• Narrow Field Video is Common
• Laser Graphics - Full or Partial Dome
• Combination Large-Format Film, Planetarium
• Total Annual Attendance Worldwide 87,400,000

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Planetarium Facts

• Planetarium
  Worldwide of
• Classification of
  Theaters Total
• School/District 999 36
• University/College 397 14
• Museum/Science Center 375 14
• Observatory/Other 201 7
• Unclassified 782 28
• TOTAL 2754

Courtesy The LNP Planetarium Compendium, Loch
Ness Productions, 2000
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Planetarium Facts

• Dome Size (m) of Theaters Tilted
  Domes
• 3 - 6 766 2
• 6 - 9 696 3
• 9 - 12 463 9
• 12 - 15 191 23
• 15 - 18 98 17
• 18 - 21 102 34
• 21 - 27 80 40
• Portable 774

Courtesy The LNP Planetarium Compendium, Loch
Ness Productions, 2000
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Large-Format Film Theater

• Hemispheric Projection Screen
• Tilted 20-30º typically
• Large-Format Film
• 15-perf, 70mm (original IMAX format)
• 8-perf, 70mm (increasingly popular format)
• Dome Diameters from 15m to 28m
• 254 LF Theaters Worldwide - Half are Domes
• 175 Large-Format Films Released

From White Oak Associates, Inc. Inventory of
Large Format Theaters, 1998 edition
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Digital Planetarium

• Full Dome or Partial Dome Video Projection
• Multiple Edge-Blended Projectors or Fisheye
• CRT, DLP, LCoS projector technologies
• 30 Existing/Planned Theaters by 7 Manufacturers
• Most Use Pre-Rendered, Pre-Recorded Shows
• Hi-res digital video graphics technologies
• Realtime 3D Interactive Becoming Affordable

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Digital Dome Manufacturers

• Evans Sutherland - Salt Lake City, UT
• GOTO Optical - Japan
• Spitz, Inc. - Chadds Ford, PA
• Sky-Skan - Nashua, NH
• Trimension, Inc. - Burgess Hill, UK
• Silicon Graphics/Zeiss/Schneider
• Minolta - Japan

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Sampling of Digital Planetaria

• AMNH/Rose Center - New York City
• Bibliotheca Alexandria - Alexandria, Egypt
• Burke Baker Planetarium - Houston, Texas
• Exploration Place - Wichita, Kansas
• National Space Centre - Leicester, UK
• LodeStar Planetarium - Albuquerque, NM
• Northern Lights Centre - Watson Lake, Yukon
• National Air and Space Museum - DC
• Adler Planetarium - Chicago

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Sampling of Digital Planetaria
Bibliotheca Alexandria Alexandria, Egypt
LodeStar Planetarium Albuquerque, NM
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Spherical Projection Formats
Single Projector(Fisheye)
Edge-Blended Projectors
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Edge-Blended Projection
Polar Source is Split Into Sub-Frames and
Edge-Blended
Sub Frame 1 Sub Frame 2 Sub Frame 3 Sub
Frame 4
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Fisheye Projection
Polar Fisheye Source Image

• Simple Configuration
• Limited Hemispheric Resolution (2048x1536 pixels)
• Requires Projector Inside Theater Space

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Feeding the Digital Planetarium

• Astronomical Visualization
• Night sky visualization
• Naked eye and deep sky
• 3D visualization and simulation
• Astrophysical models
• Digital Galaxy, Cosmic Atlas, Deep Space
  Explorer, etc.
• Informal Educational Programming
• Need compelling, meaningful stories
• What is our place in the universe?
• Whats out there?
• What does it all mean?
• My future, mankinds future
• Data queries data interpretation
• Visualization data mining, formatting

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Who Are We?

• Public Planetaria
• Science astronomy educators
• Media/production staff
• Astronomers
• School Planetaria
• Science and astronomy educators
• Show Producers
• Writers
• Art directors
• Animators
• Editors
• Musicians

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Graphics Formats

• Pre-Rendered Shows
• Dome master format
• Composited Images
• All-Sky Images
• Deep-Sky Objects
• Realtime 3D
• Texture maps
• Star/Object Data

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Pre-Rendered Shows

• Dome Master Formats
• Spherical mapping format
• Master format for archiving, distribution, etc.
• Independent of particular projection geometry
• Defined only by resolution, field-of-view, file
  type
• independent of specific projection scheme

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Polar Fisheye Master
Longitude
0º
90º
90º
-90º
0º
Polar Fisheye(Azimuthal Equidistant)
-90º
180º
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Equidistant Cylindrical Master
Equidistant Cylindrical
90º
0º
Latitude
-90º
-180º
0º
180º
Longitude
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Skinning a Sphere with Platonic Solids
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Cubic Master
Advantage - Efficient File FormatDisadvantage -
Scene is Broken Up, Difficult to Preview
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Vis Needs Pre-Rendered Shows

• All-Sky Images
• Celestial sphere at all available wavelengths
• specified coordinate system
• compositing must be seamless, no missing data
• Numerous mappings acceptable
• azimuthal equidistant (separate hemispheres)
• equidistant cylindrical
• Hammer-Aitoff
• cubic
• Deep-Sky Objects
• Need sufficient metadata!

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All-Sky Image Resolution

• Number of Pixels Required to Project Eye-Limited
  Resolution on Hemisphere

Number of Pixels
(0.5) (4? steradians) (57.3/steradian)2 (60 arc
min/deg)2
(0.5 arc min/pixel)2
300 Million Pixels!!!
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All-Sky Image Resolution

• Fisheye Projection Systems
• 1024x1024 or 1536x1536 polar frame
• Edge-Blended Projection Systems
• up to 4000x4000 polar frame
• Highest Resolution All-Sky Images in Use
• 14,000x7200 equidistant cylindrical (3 arcmin)
• Nearly 300 MB file!
• Seamless Transition to High-Magnification Images
• Deep sky zoom with higher resolution

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Deep Sky Objects

• Many Excellent Images Available from STScI/Aura
• Where Do They Go in the Night Sky???
• Need Metadata!
• Image angular height/width
• Image center RA/Dec
• Image rotation w.r.t. celestial coordinates
• Image brightness/magnitude?
• Estimated object distance (for 3D systems)
• Simplified Search Capability a Plus

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Deep Sky Zoom
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Deep Sky Object Resolution

• Higher Resolutions allow Seamless Zooms
• 1024x1024 useful
• 4000x4000 better
• 8000x8000 best!

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Image Formats

• Numerous Formats in Use
• TARGA is currently most popular format
• Compression artifacts can be a problem
• High Dynamic Range Formats Needed
• Display dynamic range limited (10001)
• HDRI, Cineon, others

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Other Ideas

• Automated Downloads
• Solar weather
• Solar system images, data
• Transient phenomena
• Current terrestrial/space based images
  metadata
• Edu releases current event items
• Connecting People Resources
• Not all data is accessible online
• Queries can actually drive future research
• Amateur astronomer image exchange
• Astronomers have stories to tell we need stories

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Thanks...