With the new of DigiTerra Explorer it is possible prepare individual base maps from online sources and use them during data collection. This can be done without Internet connection in the field!
Navigation with free high-resolution aerial imagery and maps
During field data collection, a satellite image, an aerial photograph or even a topographic map improves significantly the quality of mobile mapping. All these data are accessible but often with difficulties and high costs. However, when using smart phones during online navigation or browsing websites, several free aerial maps are available from online sources. The question arises: if the online version is free, why can't we take them with us to the field? The data would still be free, but we should use a mobile phone with GPS in one hand for displaying maps, and a PDA for data capturing in the other hand. Surely, this would be expensive and extremely inconvenient.