# Digital 3D Hologram Generation Using Spatial and Elevation Information
## 3 Results and Discussion
### Conducted Distance Measurement Procedures  
In the hologram map we developed, we performed measurements to assess whether our approach could overcome the limitations identified in previous hologram maps through our research. The map is constructed at a scale where 1 cm represents a distance of 220 m. We incorporated the map's scale into our subsequent calculations. For the experiment, we selected six arbitrary points labeled A, B, C, D, E, and F, as shown in Figure 6.  
In the hologram we developed, we include contour lines to depict elevation data, analogous to those found in conventional topographical maps. By interpreting the contour lines, we can obtain the elevation data for any point on our hologram map. We can easily measure the horizontal distance between two points using a ruler or other measuring tools, in a manner akin to measuring distances on conventional paper maps. After completing the measurements, we determined the heights of the points, the height differences, and the horizontal distances between them, as detailed in Table 1.  
Figure 6: Distance measurement between two points on a map: (**a**) distance between points A and B; (**b**) distance between points C and D, and between points E and F.  
We obtain the following horizontal distances between selected points on the map: 2.5 cm between points A and B (Figure 6a), 3.2 cm between points C and D, and 2.3 cm between points E and F (Figure 6b). Using the map scale of 220 m per centimeter, these distances translate to real-life distances of 550 m, 704 m, and 506 m, respectively. For ease of reference in our subsequent work, we will denote the distance between the points as \(\Delta d\).  
Via the analysis of the elevation data obtained from the map, we measured the height differences between points A and B, C and D, and E and F. In the subsequent part of this study, for convenience, we denoted the height differences as \(\Delta h\). We can now calculate the distance between the two points using these values by applying the Pythagorean theorem. We consider the hypotenuse as the actual distance that needs to be calculated. We regard the height difference and the horizontal distance as the remaining two sides of the triangle. For simplicity, we defined the actual distance between two points as L.  
Following the measurement of horizontal distances and vertical elevation changes between two points with our advanced hologram map, we can compute the required parameters by employing the Pythagorean theorem. The distance between points A and B calculated using the Pythagorean theorem was 592 m with a slope angle of \(\alpha=21.6^{\circ}\). The distance between points C and D, as calculated using the Pythagorean theorem, is 752 m with a slope angle of \(\alpha=20.3^{\circ}\). The distance between points E and F, calculated using the Pythagorean theorem, is 566 m, and the slope angle is \(\alpha=26.3^{\circ}\).  
We explored the measurement of distance on a hologram map in the preceding discussion. The findings demonstrate that the method employed in this experiment allows for accurate distance measurement and precise determination of the area's slope angle, offering substantial benefits [34; 35]. Utilizing the hologram map we developed enables the acquisition of geographic information as precise as that from conventional 2D maps while providing a true three-dimensional representation of the area. Our new hologram map overcomes the distance measurement limitations found in earlier hologram maps.