  Galactic interstellar emission contributes substantially to Fermi LAT
observations in the Galactic plane, where the majority of Supernova Remnants
(SNRs) are located. We have developed a method to explore some systematic
effects on SNRs' properties caused by interstellar emission modeling. We
created eight alternative Galactic interstellar models by varying a few input
parameters to GALPROP, namely the height of the cosmic ray propagation halo,
cosmic ray source distribution in the Galaxy, and atomic hydrogen spin
temperature. We have analyzed eight representative candidate SNRs chosen to
encompass a range of Galactic locations, extensions, and spectral properties
using the eight different interstellar emission models. The models were fitted
to the LAT data with free independent normalization coefficients for the
various components of the model along the line of sight in each region of
interest. We will discuss the results and compare them with those obtained with
the official LAT interstellar emission model.
