| Name
| Abbreviation
| Remarks
| Location
|
| Anglo-Australian Observatory
| AAO
| 3.9 metre Anglo-Australian Telescope, ANU's Siding Spring 2.3 m Telescope, 1.2 metre UK Schmidt Telescope
| Coonabarabran, New South Wales (Australia)
|
| David Dunlap Observatory
| DDO
|
| Richmond Hill, Ontario (Canada)
|
| McDonald Observatory
|
| 11m Hobby-Eberly Telescope, 2.7m Harlan J. Smith Telescope, 2.1m Otto Struve Telescope
| Davis Mountains, 450 miles west of Austin, Texas (USA)
|
| Infrared Optical Telescope Array
| IOTA
|
| Amado, Arizona (USA)
|
| Euro 50
| EURO50
| 50m optical telescope (planned), cooperation from
- Tuorla Observatory, Finland
- Department of Physics, National University of Ireland
- Instituto de Astrofisica de Canarias, Spain
- Lund Observatory, Sweden
- Optical Science Laboratory, University College London, UK
- National Physical Laboratory, UK
| Roque de los Muchachos Observatory, La Palma (Canary Islands)
|
| Keck Telescopes
| Keck
| Two 10m optical/infrared telescopes (occasionally used as an astronomical interferometer)
| Mauna Kea, Hawaii (USA)
|
| Magdalena Ridge Observatory Interferometer
| MRO
| Astronomical interferometer which will have up to ten telescopes, providing the highest resolution optical images in the world
| Magdalena Ridge, New Mexico (USA)
|
| Nordic Optical Telescope
| NOT
| 2.6m optical/infrared telescope.
| Canary Islands, Spain
|
| Overwhelmingly Large Telescope
| OWL
| Conceptual design of a segmented mirror telescope with a single aperture of 100 meters in diameter.
| Still on research status.
|
| Thirty meter telescope
| TMT
| Conceptual design of a segmented mirror telescope with a single aperture of 30 meters in diameter.
| Still on research status.
|
| Southern African Large Telescope
| SALT
| At 11m, the biggest telescope in the southern hemisphere of the Earth.
| Karoo, South Africa
|
| Very Large Telescope
| VLT
| Four separate 8m optical/infrared telescopes (occasionally used as an astronomical interferometer).
| Paranal Observatory, Chile
|
| William Herschel Telescope
| WHT
| 4.2m optical/infrared telescope.
| Canary Islands, Spain
|
|
| LAT
| 1.8m (70 inch) Amateur telescope, under development
| TBD, California (USA)
|