Apple LiDAR Sensor for 3D Surveying: Tests and Results in the Cultural Heritage Domain

Abstract

The launch of the new iPad Pro by Apple in March 2020 generated high interest and expectations for different reasons; nevertheless, one of the new features that developers and users were interested in testing was the LiDAR sensor integrated into this device (and, later on, in the iPhone 12 and 13 Pro series). The implications of using this technology are mainly related to augmented and mixed reality applications, but its deployment for surveying tasks also seems promising. In particular, the potentialities of this miniaturized and low-cost sensor embedded in a mobile device have been assessed for documentation from the cultural heritage perspective—a domain where this solution may be particularly innovative. Over the last two years, an increasing number of mobile apps using the Apple LiDAR sensor for 3D data acquisition have been released. However, their performance and the 3D positional accuracy and precision of the acquired 3D point clouds have not yet been fully validated. Among the solutions available, as of September 2021, three iOS apps (SiteScape, EveryPoint, and 3D Scanner App) were tested. They were compared in different surveying scenarios, considering the overall accuracy of the sensor, the best acquisition strategies, the operational limitations, and the 3D positional accuracy of the final products achieved.

Smartphone LiDAR Data: A Case Study for Numerisation of Indoor Buildings in Railway Stations

“…Surface acquisition: Overall, the plane-fitting investigation showed a local accuracy of 1 to 3 mm and an average density around 19,000–20,000 pts/m 2 for the LiDAR smartphone data use with the 3D Scanner application. These accuracy levels are also observed in studies conducted with the same type of LiDAR on the iPad Pro in open indoor spaces by using the same application [ 27 , 28 , 30 ]. However, these are still relative accuracies that are highly dependent on the digitised environment.…”

“…As the acquisition areas increase, the accuracy errors increase. This is confirmed by comparing the percentage deviation (FARO-LiDAR smartphone) <5 cm between the largest and smallest environment (rep 78% for the parking, 79% for the warehouse, and 89% for the local) whereas existing work on iPad and iPhone 12 LiDAR sensors shows percentage deviation measurements (FARO-LiDAR smartphone) of more than 85% on outdoor and indoor scans [ 28 , 30 ]. The loss of accuracy with increasing space is also observed in the measurement tests in 4.2.1 where the accuracy deteriorated as the area scanned increased.…”

“…There are also other applications that are equipped with both functionalities, such as the recently released 3D Scanner App [ 26 ]. In the context of our experimentation, we chose to use the 3D Scanner App LiDAR application because of its simplicity of use and the ease with which it generates surfaces with mesh during scanning [ 33 ] and the less noisy surface reconstruction [ 30 ].…”

“…In a recent work, Teppati and al. [ 30 ] have evaluated the accuracy and precision of the point cloud of an Apple LiDAR by testing them on different iOS applications (SiteScape, EveryPoint, and 3D Scanner App). Different materials were used depending on the natural sunlight and the results had to show the level of noise and the mode of acquisition with the iOS application.…”

“…Our experimental approach includes a controlled environment study and a field (in situ) study (where the sensors are tested in different environmental settings). For the in situ tests, we make a comparison of the data captured by the smartphone with those captured with a TLS scanner [ 28 , 29 , 30 ]. However, in our work, the digitised environments are chosen according to the constraints that the space of the station buildings may present.…”