A robust system and method for positioning and heading for guidance or logging agricultural input placement amounts and locations is disclosed and can be used to aid or direct treatment of a field that has only partial or temporary access to a reliable GNSS signal. The guidance information or data can be stored in memory and output to a video display terminal or the visual display of a computing unit (e.g. laptop or user mobile phone) or alternative formatted or translated to produce an output on a heads-up display such as a light bar.
