Avionics: Using custom PCB to command optical set up and data log. Optical Setup: Toptica iBeam Smart PT:

• Output power: 50mW

• Wavelength: 520 +/- 5 nm

• Analog modulation up to 500 kHz

• Pulse option, including up to 10 MHz auto pulse, or modulation bandwidth up to 250 MHz

• Laser not aligned with transit of particles, Pigtail collimation necessary to orientate beam path with particle transit

Currently, we are in the process of finding sensor, lenses and collimators to complete the optical setup

Aims

Simulations

-Diffraction simulated using diffraction.sim library from GitHub.

-Different microscope images of particles from the internet were used as samples.

-Simulated over different distances from the detector.

Software and Image Propagation

The role of the software will be to initially convert the raw diffraction patterns, captured by the optical system, to usable particle information. The frames are predicted to typically contain a smaller number of particles but at high diffraction, so in that case the core task is numerical reconstitution of particle images using Fourier-based propagation methods. Overall, the software serves as the computational bridge between raw optical holograms and actionable particle analytics.

Desired conclusions

Once the images are reconstructed, we can extract meaningful measurements such as particle size, shape, using more frames to get speeds, directions, and classify the particles. This can be matched up to altitudes to form vertical profiles comparing their size and shape distributions through the low atmosphere. In the case of multiple particles with lower diffraction spread, the same pipeline can extend to further count particles in the frame and segment overlapping diffraction rings.