Method for data collection and integration into 3D architectural model

Abstract

Rapid development in the field of smartphones over past years has enabled using their multimedia capabilities in virtually reconstructing and visualizing architectural objects by creating 3D-models of such objects. Several authors have tested cell phone cameras accuracy. For example Nokia N93, Sony Ericsson K750i, iPhone placed under test could be successfully used in applications not requiring ultimate precision [Gruen A, Akca D (2009) Evaluation of metric performance of mobile phone cameras. Institute of Geodesy and photogrammetry, ETH, Zurich. doi:10.3929/ethz-a-005749738; Takahashi Y, Chikatsu H (2009) 3D Modelling and visualization of cultural heritage using mobile phone cameras. In: Proceedings of the 3rd ISPRS international workshop 3D-ARCH, Trento]. Rapid technical development in the field of unmanned aerial vehicles (UAV) and lowering of their cost has made them available practically for everyone interested and eased tremendously use of such machines in aerial photography and photogrammetry [Eisenbeiss H (2009) UAV photogrammetry. Ph.D thesis, Dissertation ETH no. 18515, ETH Zurich; Remondino F, Barazzetti L, Nex F, Scaioni M, Sarazzi D (2011) UAV photogrammetry for mapping and 3D . In: Proceedings of the international conference on unmanned aerial vehicle in geomatics (UAV-g), Zurich]. We used Nokia N8 smartphone in our study since it had best optical, computing and communications capabilities at the time of this writing. In present paper we illustrate two ways of using smartphone's camera in mapping object's properties. One is a well known method of photogrammetric 3D-modelling. Another is a less used method of photogrammetric positioning [Dillon MJ, Bono RW, Brown D. L (2004) Use of photogrammetry for sensor location and orientation. IMAC-XXII: conference and exposition on structural dynamics, Jacksonville; Mautz R, Tilch S (2011) Survey of optical indoor positioning systems. In: Proceedings of the international conference on indoor positioning and indoor navigation, Guimarães]. Firstly we demonstrate mapping of moisture content using photogrammetric positioning of sensor. Mechanically rigidly connected moisture probe and phone (together with built-in camera and special software) are linked via a bluetooth adapter enabling thus synchronisation of moisture measurement results to exact location. Individual results are stored directly to accompanying image file used for positioning each measurement. Such approach should eliminate possible human errors common in long and tedious measurements. Secondly a 3D model of a Tallinn Observatory tower is created by traditional means using phones built-in 12 megapixel camera. Low weight of the phone (about 120 g) enabled transporting it to suitable photographing positions onboard an airborne UAV. Described in present paper method is suitable for 3D-mapping of a large variety of physical properties of objects in interest. © 2013 Springer Science+Business Media.