A Self-made Goniometer

 Building a Low-Cost Automated Goniometer for Light Scattering Studies

In my 2020 work published in the European Journal of Physics, I described the design and fabrication of a self-made, fully automated goniometer for studying light scattering in planetary science. Commercial systems are often expensive and purpose-specific, so I set out to create a cost-effective, versatile alternative without compromising accuracy.

My design uses Arduino microcontrollers, stepper motors, and a green diode laser with a sensitive light-to-frequency detector. The setup automates movement of both the light source and detector arms, enabling measurements over a wide range of scattering angles. Calibration with Lambertian surfaces ensures reliable bidirectional reflectance data.

This instrument successfully measured scattering from regolith analogs such as sugar and NaCl, producing phase curves consistent with known scattering behavior. Beyond planetary science, it offers educational and research value for optics, remote sensing, and materials studies—proving that high-quality instrumentation can be built in-house on a modest budget.



Comments

Post a Comment

Popular posts from this blog

A Simple Way to Find Wavelength of Light Accurately by Using Webcam

Image
How can we measure the wavelength of a laser beam with simple, low-cost tools? In our recent work, " Measuring wavelength of laser beam using single slit diffraction: a simple but precise experiment using webcam and ImageJ software " we revisited the classic single-slit diffraction experiment but gave it a modern upgrade. Traditionally, this experiment involves photodiodes and optical benches, with painstaking manual measurements that are often error-prone. Instead, we used a paper screen, a regular webcam, and free software to make the process faster, easier, and more accurate. The setup is simple: a laser beam passes through a narrow slit, producing a diffraction pattern on the screen. A webcam captures this pattern, and the free image-processing software ImageJ is used to measure the span of the central bright region. From this, we calculate the wavelength of the laser. Using this method, we tested both a known red He–Ne laser and a green diode laser , achieving resu...
Read more

Shadow2Profile - an Image to Roughness Estimation software

Image
Estimating Surface Roughness from a Single Image Measuring surface roughness is vital in fields from manufacturing to planetary science, yet traditional methods—profilometers, laser scanners—are costly and limited in scope. My 2025 Measurement paper presents a simple, computational technique that uses just one digital image of a surface illuminated at a known angle. The method analyzes shadow patterns cast by microscopic “hills” onto “valleys” and compares them with computer-generated profiles until the best match is found. From this, key roughness parameters—average height deviation (Ra) and average slope angle—are calculated. The technique works for a wide range of scales, from microscopic samples to landscapes, and requires minimal equipment. Open-source software, Shadow2Profile , was developed for Windows and Linux, enabling anyone to apply this approach to their own images. This innovation could benefit remote sensing missions, material testing, and any scenario where convention...
Read more