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The Landsat Data Continuity Mission (LDCM) focuses on a next generation global coverage, imaging system to
replace the aging Landsat 5 and Landsat 7 systems. The major difference in the new system is the migration
from the multi-spectral whiskbroom design employed by the previous generation of sensors to modular focal
plane, multi-spectral pushbroom architecture. Further complicating the design shift is that the reflective and
thermal acquisition capability is split across two instruments spatially separated on the satellite bus. One of the
focuses of the science and engineering teams prior to launch is the ability to provide seamless data continuity
with the historic Landsat data archive. Specifically, the challenges of registering and calibrating data from the
new system so that long-term science studies are minimally impacted by the change in the system design. In
order to provide the science and engineering teams with simulated pre-launch data, an effort was undertaken to
create a robust end-to-end model of the LDCM system. The modeling environment is intended to be flexible
and incorporate measured data from the actual system components as they were completed and integrated.
The output of the modeling environment needs to include not only radiometrically robust imagery, but also
the meta-data necessary to exercise the processing pipeline. This paper describes how the Digital Imaging
and Remote Sensing Image Generation (DIRSIG) model has been utilized to model space-based, multi-spectral
imaging (MSI) systems in support of systems engineering trade studies. A mechanism to incorporate measured
focal plane projections through the forward optics is described. A hierarchal description of the satellite system
is presented including the details of how a multiple instrument platform is described and modeled, including
the hierarchical management of temporally correlated jitter that allows engineers to explore impacts of different
jitter sources on instrument-to-instrument and band-to-band registration. The capabilities of a new, non-imaging
instrument to simulate the measurement of platform ephemeris is also introduced. Finally, the geometric and
radiometric foundations for modeling clouds in the DIRSIG model will be described and demonstrated as one of
the more significant challenges in registering multi-spectral pushbroom sensor data products.
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