A PBeL for training non-experts in mobile-based photogrammetry and accurate 3-D recording of small-size/non-complex objects

The high level of automation, user-friendliness and cost-effectiveness of photogrammetry have contributed significantly to its popularisation among amateur users in recent years. Paradoxically, this situation poses challenges when relying on the accuracy of the derived 3-D products requiring control procedures to be implemented. In this context, we present a case study of the D3Mobile project: a fully online competition for participants worldwide funded by the International Society of Photogrammetry and Remote Sensing (ISPRS). The aim is for participants to obtain reality-based 3-D models using their own mobile phones and to critically examine the metric accuracy that hides behind the beguiling realism of photogrammetry. The relative precision of the former participants’ models reached values around 1:2,000, proportionally to the object size. These results provide an idea of the current level of development of photogrammetry and the potential it offers for any kind of user after proper capacity building and training.