  We use a Fourier transform spectrometer based on a compact mid-infrared
difference frequency generation comb source to perform broadband
high-resolution measurements of nitrous oxide, $^{14}$N$_2$$^{16}$O, and
retrieve line center frequencies of the $\nu$$_1$ fundamental band and the
$\nu$$_1$ + $\nu$$_2$ - $\nu$$_2$ hot band. The spectrum spans 90 cm$^{-1}$
around 1285 cm$^{-1}$ with a sample point spacing of 3 ${\times}$ 10$^{-4}$
cm$^{-1}$ (9 MHz). We report line positions of 67 lines in the $\nu$$_1$
fundamental band between P(37) and R(39), and 78 lines in the $\nu$$_1$ +
$\nu$$_2$ - $\nu$$_2$ hot band (split into two components with e/f rotationless
parity) between P(34) and R(33), with uncertainties in the range of 90-600 kHz.
We derive upper state constants of both bands from a fit of the effective
ro-vibrational Hamiltonian to the line center positions. For the fundamental
band, we observe excellent agreement in the retrieved line positions and upper
state constants with those reported in a recent study by AlSaif et al. using a
comb-referenced quantum cascade laser [J Quant Spectrosc Radiat Transf,
2018;211:172-178]. We determine the origin of the hot band with precision one
order of magnitude better than previous work based on FTIR measurements by Toth
[http://mark4sun.jpl.nasa.gov/n2o.html], which is the source of the HITRAN2016
data for these bands.
