Research directorate / PO
Acquisition, visibility, and continuous coverage.
Persistent Observation coordinates distributed sensing and orbital acquisition to maintain usable records across changing environmental conditions. The directorate assesses instrument availability, horizon constraints, and the intervals between successive observations. Visibility is evaluated from the observing system’s perspective. A record is considered continuous when the combined acquisition windows satisfy the assigned coverage requirement, even where no individual instrument remains in position for the complete interval.
Periods traditionally classified as unobservable have been reduced through overlapping acquisition windows. Current work concentrates on transfer between systems, consistency of time references, and the treatment of partial observations. Subject participation is not required for continuity of coverage. Assessment therefore separates the availability of a record from any response associated with its acquisition. Where observations are under review, the original sequence is preserved so that subsequent interpretation does not alter the conditions under which the record was obtained.
Program areas
Combine distributed and orbital observation windows into a common acquisition schedule. Instrument sequences are aligned to the same time reference and checked for usable overlap. The program evaluates coverage at the boundary between systems, where individual records may otherwise appear complete.
Assess exposure, horizon conditions, and usable visibility intervals. Trials compare nominal lighting conditions with the information available to each observing system. Assessment windows are retained long enough to distinguish a temporary reduction in signal from an interruption in acquisition.
Identify and reduce gaps between observing systems. Planned transfers are tested against the full reference cycle, with duplicate records retained where they support reconciliation. Continuity is measured at the combined-system level and reported independently of the number of active instruments.
Reported coverage excludes intervals for which observation remains under review.