An anodic double layer gasochromic sensor structure for optical detection of hydrogen in improved response time and with improved optical absorption real time constants, comprising: a glass substrate; a tungsten-doped nickel oxide layer coated on the glass substrate; and a palladium layer coated on the tungsten-doped nickel oxide layer. The rocket engine includes a combustion chamber having an injector end and a nozzle end. A heading error estimate is updated based on the updated current heading estimate, and an estimated drift rate is determined based on the heading error estimate and an operational latitude. Each recess has two first interference blocks. Particularly preferred supported catalyst systems are those comprising metallocene complexes.