# Super-Resolution Remote Imaging Using Time Encoded Remote Apertures
## 5 Proof of Concept Experiments  
In this section, we demonstrate the performance of the algorithm using experimental data. The experimental setup is shown in Figure 5a. The imaging system contains an ultra-fast laser (One Five Katana HP amplified diode laser) that emits laser pulses with 50 ps width and 10 MHz repetition rate. An example of the laser illumination area is shown in Figure 5d. The laser has 1 W emission power at the wavelength of 532 nm. The scene is located around 4 m away from the imaging system. The returning scattered light from the scene is collected by a SPAD (PMD series), which has 20 micron diameter active-area. The SPAD has a photon detection efficiency of 49% at wavelength 555 nm. The dark count rate(DCR) is 10 photons per second. After pulsing probability(AP) is 0.1-3%. Dead time is 77 ns. The SPAD is coupled with a time-correlated single-photon counter (PicoQuant HydraHarp). The total effective temporal impulse response of our imaging system is 80 ps. Exposure time for each scene capture was set to 2 min. Note that we do not use any lenses in front of the SPAD. Figure 5b,c,e,f show examples of experimental scenes. The scene is located approximately 4 m away from the imaging system. Circular patches and stars have a size of 4 \(\times\) 4 cm, and the plane is 8 \(\times\) 8 cm. First, we test the method using two circular patches. We place to patches 15 cm apart from each other and move them apart up to 35 cm with 1 cm spacing (21 different positions). Note that one patch is stationary, while another is moving. See Figure 6. The first column shows the actual scene picture. The second column is a reference simulated picture of the scene using a camera with an aperture size of 20 microns. The ground truth scene has been captured while using a regular camera, and the image was convolved with a blur kernel that corresponds to 20 micron sensor at the corresponding depth. The third column is a reconstruction of the scene using acquired data. Finally, the fourth column shows the actual data. In the reconstruction, one can see that the two patches clearly are separated. Figure 7 shows a plot of ground truth (green) and reconstructed (blue) distances. The RMS error between ground truth and reconstructed distances is 0.03 cm. Next, we test the method using different targets (star, plane, circular patch). Note that the circular patch and plane are white and they have diffuse surfaces, whereas stars are brown and made of wood. See Figure 8a,b. One can notice that the shape of the star and plane's peak are slightly different from the circular patches, but still, three peaks exist in the data. Stars have sharper and more pronounced peaks, whereas planes have  
Figure 4: Statistical analysis of scene recoverability. The plot shows the probability of correctly imaging all targets in a scene of spheres randomly placed in a volume of 10 cubic meters. The number of spheres varies from five to 20 and the sphere diameter from 1 to 8 cm. The plot is generated from simulated data using the realistic parameters of detector and photon noise and assuming a 10 W illumination pulse from the laser. wide peaks. Lastly, in Figure 8c, the reconstruction of three circular patches is shown. In the data, there are three first bounces and three second bounces peaks. As was mentioned in the simulation section, in some cases, it is possible for objects to block some light paths, which results in missing peaks in the collected time response. Peaks may also be too weak to detect and be missing for that reason. We can reconstruct vertexes that have at least one first and two second bounce distance peaks preserved in the data (Section 3.2). The objects can also have low reflectance or be not well-orientated, which may lead to lower peak intensity. However, as long as the peak is detected, the actual intensity is not relevant. If needed, one can increase exposure time or laser power to get a better signal. Additionally, peaks can also overlap with each other.