Why OHANA?

Two recent technological breakthroughs make such a project feasible, at least in theory:

• Large telescopes can now be equipped with adaptive optics, providing Strehl ratios at least 0.3 at 2 microns on faint sources ($R<14\sim 15$).
• Coherent light transport on short distances (10 meters) and coupling with single mode fibers in K and L bands is routinely demonstrated with the IOTA/FLUOR interferometer, leading to scientific results with unprecedented quality of visibilities (0.3% stability)

There is no other site on earth which provides the combination of superb seeing, largest collecting areas with adaptive optics, near kilometric baselines. For reference, it should be reminded that the resolution at 2 microns of an 800 meter baseline such as that defined by Keck and CFHT or Gemini is 0.5 milliarcseconds (Figure 2.). However, such a project would also require the cooperation between observatories with different goals, policies and funding agencies. Furthermore, the severe competition for observing time should be weighted against the scientific potential of such an interferometric array.