A method is presented for the conversion of an HF oblique ionogram to an ionospheric density true height profile, within the usual approximations of spherical symmetry and no magnetic field. It is a lamination method for inversion of the equations for group path delay and sounder range, which are treated on equal footing, similarly to an earlier method by Rao. A reentrant procedure has been added to alleviate the problem of valley ambiguity. Use of the method and its clear improvement over other methods, which invoke further approximations, are demonstrated by calculations on oblique ionograms from known, model daytime profiles. Future directions are indicated.