[U-04] Geospatial Applications for Societal Benefits

[U04-08] Real-Time 4-Band Spectral Camera: Development and Field Applications for Environmental Measurements

*Ahmad Shaqeer Mohamed Thaheer¹, Garid Zorigoo¹, Tatsuharu Ono¹, Yukihiro Takahashi¹ (1.Department of Cosmosciences, Faculty of Science, Hokkaido University)

Keywords:Multi-band Camera, Spectral Measurement, Realtime Analysis

Understanding environmental parameters is crucial for assessing environmental conditions accurately. Studies focusing on crop health, water pollution, and fruit quality assessment could achieve significant advancements if evaluations were available in real time. Recent developments in remote-sensing technologies for predicting these parameters have provided rich spectral and spatial data, demonstrating remarkable performance in estimation and identification. Additionally, in-situ measurements serve as critical tools for the verification and validation of remotely obtained results. However, both methods face limitations: remote sensing often suffers from low temporal resolution, requiring several days for updated data, while in-situ methods necessitate laboratory analysis, causing delays in obtaining actionable insights. To address these challenges, we present the implementation of a real-time 4-band spectral camera for environmental assessment. The camera is composed of four monochromatic global shutter cameras, synchronized at the hardware level to capture the same scene simultaneously. Four bandpass filters were selected based on a prior band selection study, ensuring optimal spectral performance. To balance intensity levels across all cameras, neutral density filters were employed on select cameras. A feature transformation algorithm was applied to the captured images to identify and match local features, enabling pixel-level correction across the four bands. The corrected images were then processed and transmitted via a ZeroMQ framework. This framework facilitates efficient data transmission, with the client retrieving the computed image for further analysis. The multiband spectral camera has compact dimensions of 10 × 10 × 10 cm and weighs only 500 grams. It is powered via a USB-C connection and outputs data through an Ethernet port. Additionally, data can be stored locally on an SD card for offline analysis. This lightweight and portable design allows the camera to be integrated into various platforms, including drones, autonomous robotic vehicles, or conveyor systems, making it highly versatile for a wide range of environmental applications.