Abstract:
At 26Tb/day return average, NISAR (National Aero-
nautics and Space Administration (NASA) and the In-
dian Space Research Organization (ISRO) Synthetic
Aperture Radar) will stress ground station facilities
with a variable cadence of data generation observing
nearly all of earth's land and ice to produce global time-
series maps of cryospheric, solid-Earth and ecosystem
phenomena. Between the instrument data generation
source and downlink sink lies the primary science data
bu er, the SSR (Solid State Recorder).
The SSR has deferred, discrete le deletion events that
occur only after a le is played back to all required
ground segments (sometimes both NASA and ISRO).
A forward dispatch, advancing frontier repropagation
playback scheduler is proposed as a model of the SSR's
greedy playback scheduling behavior. Schedules based
on the existing low delity model and new intermediate
delity model are compared to assess the impact of
deferred, discrete deletion on planning. The low delity
model is found to produce unfeasible schedules that
exceed SSR capacity, causing 3.87% of all observations
in a 12 day simulation to be removed by repair actions.
