The “Maritime Autonomous Navigation using Alternative Absolute positioning techniques” (MANAA) project will provide new ways of integrating millennia old celestial navigation techniques with state-of-the-art technology and thinking, whilst developing visual and non-visual spectrum optical techniques and sensors with the potential to observe celestial bodies independently of the lighting and weather conditions. MANAA will develop algorithms to process the acquired data, combining it with other typical maritime sensors such as IMUs to achieve a non-RF dependent positioning solution in open sea. RF techniques will therefore be used only for error bounding and given minimal recognition in the developed techniques. This work will build upon a thorough state-of-the-art review, and this will be used to elicit user and system requirements for the design.