  The baryon acoustic oscillation feature can be used as a standard
cosmological ruler. In practice, for sub-percent level accuracy on the distance
scale, it must be standardized. The physical reason why is understood, so we
use this to develop an algorithm which improves the estimated scale. The
algorithm exploits the fact that, over the range of scales where the initial
correlation function is well-fit by a polynomial, the leading order effects
which distort the length of the ruler can be accounted for analytically. Tests
of the method in numerical simulations show that it provides simple and fast
reconstruction of the full shape of the BAO feature, as well as sub-percent
determination of the linear point in the correlation function of biased tracers
with minimal assumptions about the underlying cosmological model or the nature
of the observed tracers. Our results also suggest that, for least squares
estimators of the correlation function, half-integer generalized Laguerre
functions are a particularly useful choice.
