This correspondence deals with parameter estimation of product signals cons
isting of hyperbolic FM and chirp factors. A computationally simple algorit
hm that decouples estimation of the chirp parameters from those of the hype
rbolic FM part is presented. It relies on a simple data transformation that
removes the hyperbolic FM component. leaving one with the simpler problem
of estimating chirp parameters, For the latter, the high-order ambiguity fu
nction (HAF) is adopted, Schemes for estimating the hyperbolic FM parameter
are also proposed, The method improves on existing approaches and is shown
to provide performance close to the Cramer-Rao bound.