Extrapolation Techniques and Systematic Uncertainties in the NO$\nu$A Muon Neutrino Disappearance Analysis

The NOvA long-baseline neutrino experiment consists of two highly active, finely segmented, liquid scintillator detectors located 14.6 mrad off Fermilab's NuMI beam axis, with a Near Detector located at Fermilab, and a Far Detector located 810 km from the target at Ash River, MI. NO$\nu$A released it first preliminary results of the muon neutrino disappearance parameters, measuring $\sin^2(\theta_{23}) = 0.51 \pm 0.10$ and or the normal hierarchy $\Delta m^2_{32} = 2.37^{+0.16}_{-0.15} \times 10^{-3}$ eV$^2$ and for the inverted hierarchy $\Delta m^2_{32} = -2.40^{+0.14}_{-0.17} \times 10^{-3}$ eV$^2$. This talk will present a discussion of the systematic uncertainties and extrapolation methods used for this first analysis which uses $2.74\times10^{20}$ POT-equivalent collected between July 2013 and March 2015.