# Technological Development and Application of Photo and Video Theodolites
## 2 Technological Development
### Development from 2001 until Today
\begin{table}
\begin{tabular}{c c c c} \hline
**Specifications** & **Leica TS60** & **Trimble S9** & **Topcon DS-200i** \\ \hline
**Camera/sensor** & 2\(\times\)/CMOS & 1\(\times\)/CMOS & 1\(\times\)/CMOS \\
**Resolution** & 5 MPx & 3 MPx & 5 MPx \\
**Fps** & 20 Hz & 5 Hz & Live video 1  \\
**FOV overview/telescope** & 15.5\({}^{\circ}\)\(\times\) 11.7\({}^{\circ}\)/1.3\({}^{\circ}\)\(\times\) 1.0\({}^{\circ}\) & 16.5\({}^{\circ}\)\(\times\) 12.3\({}^{\circ}\)/X & Ultra-wide 1 /X \\
**Zoom overview/telescope** & 8\(\times\)/30\(\times\) & 8\(\times\)/X & 1  \\
**Accuracy distance (prism)** & 0.6 mm + 1 ppm & 0.8 mm + 1 ppm & 1.5 mm + 2 ppm \\
**Accuracy distance** & 2 mm + 2 ppm & 2 mm + 2 ppm & 2 mm + 2 ppm \\
**Accuracy Hz and V** & 0.5\({}^{\prime\prime}\) & 0.5\({}^{\prime\prime}\) & 1\({}^{\prime\prime}\) \\
**Scanning function** & X & \(\bullet\) & X \\
**Year released** & 2015 & 2015 & 2014 \\ \hline \end{tabular}
\end{table} 
Table 1: Main specifications of currently available IATS [49; 50; 51]. \(\times\) 300\({}^{\circ}\) with 84\(\times\) zoom. The general camera enables an FOV of 57.5\({}^{\circ}\)\(\times\) 43.0\({}^{\circ}\). An expert controls the instrument using a remote controller via live video at 15 fps. SX10 combines high-density 3D scan data, enhanced imaging called Trimble Vision, and high-accuracy total station data. It uses MagDrive servo technology, and it can measure dense 3D scan data at up to 26,600 points per second with high precision over the full measurement range of up to 600 m [52]. There was some confusion, even among Trimble developers, as to whether it should be considered a new scanner or a new total station. However, it is still classified as a TS because of its characteristics regarding the telescope, angle and distance measurements, and the possibility to measure explicitly one point. Since it combines imaging with scanning on a level that is not rudimentary, we can call it the first image-assisted scanning total station (IASTS). At the beginning of this year, Trimble introduced its successor SX12. The technical data offered at the moment describe the following upgrades: 8.1 MPx image sensors, 107\(\times\) zoom of the main camera, and a new laser pointer, while the remaining features regarding angle and distance measurements and scanning function are at the same level as SX10 [53]. Topcon presented its IASTS GTL-1000 in 2019, and it is the world's first RTS and laser scanner with an inbuilt camera, which is primarily used for colorizing the scanned scenes. The camera has a 5 MPx image sensor which is also used for live video. A 3D laser scanner is installed in place of the RTS handle, resulting in a solution that it is both a geodetic measuring station and a geodetic 3D laser scanner. The instrument uses direct drive via an ultrasonic motor. The main advantage of this IASTS compared to other commercially available IASTS is the scan rate, which is on the level of today's terrestrial laser scanners and is specified as 100,000 points per second. It is the first such instrument in the world [54]. In Table 2, Leica MS60, Trimble SX12, and Topcon GTL-1000 are compared with their main specifications and characteristics. All instruments have a scanning function and they are classified as multi-stations, so-called IASTS. These three instruments, at the moment, represent the state-of-the-art geodetic instruments in the world.