Covariant gauge fixing for super IIA D-branes

For the κ-symmetric super IIA D-brane action by the canonical approach we construct an equivalent effective action which is characterized by an auxiliary scalar field. By analyzing the canonical equations of motion for the κ-symmetry-gauge-fixed action we find a suitable conformal-like covariant gauge fixing of reparametrization symmetry to obtain a simplified effective action where the non-linear square root structure is removed. We discuss how the two effective actions are connected.