## 4 Results and Discussion
### Results of Camera's Orientation, Accuracy, and Precision around the X, Y, and Z Directions  
The results of the experiment to discuss the accuracy of two approaches in producing pictures resembling the reference image regarding the camera's orientations around the X, Y, and Z axes are presented in Table 2 and are explained as follows:  
**Accuracy around the X-axis (pitch)** The results of the experiment regarding accuracy (i.e., producing pictures resembling the reference picture) showed that the results in both approaches are very similar. While the orientation of the camera around the X-axis for the reference image was measured as 7 degrees, the average reference was 5 degrees for the first group of pictures and 2 degrees for the second group of pictures. Thus, the average accuracy error for pictures captured without using a sensor is slightly less (2 degrees vs. 5 degrees) than when the images were captured with the assistance of orientation sensors. This result shows that using the sensor did not improve the accuracy for rotation around the X-axis (pitch). **Accuracy around the Y-axis (roll)** The results showed that the average accuracy around the Y-axis for both approaches is the same. While the orientation of the camera for the reference image around the Y-axis measured 0, the average orientation for Groups 1 and 2 (with and without sensors) measured the same (1 degree). This result showed that when participants wanted to take pictures from a scene using their common sense, they could hold the tablet camera almost in the same orientation as when they used the orientation sensors (Table 2). However, as was indicated in the limitation section, two of the pictures captured by participants had 90 degrees rotation around the Y-axis of the tablet. Although these two exceptional pictures were discarded because of the high statistical skews that could affect the calculations, this could occur in real situations if crews are not warned in advance. **Accuracy around the Z-axis (yaw)** The results showed the average accuracy around the Z-axis for the sensor-based approach is slightly better than the non-sensor-based approach. While the orientation of the camera around the Z-axis for the reference image measured 10 degrees, the average for the non-sensor-based approach was 17 degrees and the sensor-based approach was 15 degrees. Therefore, the orientation accuracy error for the sensor-based approach (5 degrees) was slightly less than the non-sensor-based approach (7 degrees). This result indicates that the participants, using their common sense, can generate results closer to the reference than when they use sensors. In general, the degree of resemblance of the pictures produced by both approaches is very close to the reference picture. The precision of the two approaches in producing pictures resembling each other regarding orientations around the X, Y, and Z axes is presented in Table 2 and explained as follows:  
**Precision around the X-axis (pitch)** The result regarding the standard deviation for the sensor-based approach was less than the non-sensor-based approach (7 degrees vs. 2 degrees). Therefore, precision (i.e., producing pictures that resemble each other) around the X-axis improved when the participants used the sensor-based approach. While the precision error for the non-sensor-based approach was 7 degrees, this value decreased to 2 degrees when they used the sensor-based approach. Therefore, the degree of repeatability of the camera's orientation and picture resemblance for pitch increased. **Precision around the Y-axis (roll)** The standard deviation for both sensor-based and non-sensor-based approaches was almost the same (1.5 degrees vs. 1.2 degrees). Therefore, the results regarding the average precision error around the Y-axis (roll) were almost the same. **Precision around the Z-axis (yaw)** The standard deviation around the Z-axis reduced from 20 degrees to 7 degrees when participants used the sensor-based approach.