This report summarizes the project Synthetic Natural Environments 2009-2011. The main purpose of the project has been to find areas of great potential for further development, where R&D efforts are considered particularly relevant for increasing the benefit of 3D synthetic natural environment models (SNE) for the Swedish Armed Forces (SwAF). As opposed to previous projects in this area, the emphasis has no longer been on development of signal processing techniques, but rather on how existing and coming technical achievements in the field can be used as efficiently as possible to support SwAF. The basis of this work is a survey on needs and opportunities regarding SNE conducted in 2009, through enquiries, discussions with representatives from SwAF, the Swedish Defence Materiel Administration (FMV) and FOI, as well as participation in the NATO group SET-118 ("3D Modelling of Urban Terrain"). Together with existing R&D activities and technical development trends, this has resulted in three areas being identified as particularly relevant, summarized below. One area concerns interoperability, both in terms of technology for distribution of geospatial data and new 3D data models. Connecting multiple simulator systems (e.g. within the Swedish National Training Network, NTN) requires a technical infrastructure that allows for flexible handling of geographical content.In order to support SwAF in such matters, the SNE project has initiated work on implementation of a database/server platform for geospatial data distribution, based as far as possible on OGC standards. The initial use of the platform is mainly internal use at FOI, but the goal is to exploit its capabilities within NTN and other SwAF activities involving GIS. Another interoperability aspect is new, semantically enriched 3D data models that have gained popularity for "3D GIS". Interoperability issues will be the main focus for the project's work in 2012. Another issue concerns sensor technology tools for mapping in a mission area, to create geographical data and 3D models with simple vehicle-mounted sensors. A small field trial was conducted in Eksjö, Sweden 2010 together with personnel from the Göta Engineers (Ing 2) and a number of sensor-oriented projects at FOI, the goal being to establish contact with the Geo Support Groups and to gain insight in the needs of SwAF, and to let GIS personnel within SwAF take part of results from R&D projects. The third area concerns quality aspects of 3D models. Today, techniques for creating models are so mature that the users of the models could formulate more distinct requirements with respect to the intended use of the models. The key here is an increased collaboration between SwAF, FMV and FOI and the development of a methodology to address such questions. A number of quality measures have been suggested in the literature, but an approach to clarify which measures are relevant for 3D models in SwAF-related applications remains to be developed.