Field of View
6.4° × 12.8° (vertical × horizontal)
The CT instrument (flown only on EUSO-SPB2) used a 1 m diameter Schmidt telescope with four mirror segments with a bifocal alignment (meaning light focused in two distinct spots on the camera instead of one: a direct cosmic ray hit on the detector would register as a single spot, while light from outside the telescope would register as two, allowing the elimination of direct cosmic ray background noise). The camera used a 512 Silicon PhotoMultiplier (SiPM) detector to target very fast and bright signals as expected from Cerenkov emission from air showers. The CT could be pointed from horizontal to 10° below the limb, depending on science operation needs. The horizontal mode looked for direct Cerenkov light from lower-energy cosmic rays; the sub-limb mode looked for optical neutrino signatures from τ neutrino interactions.
