Fast and robust pushbroom hyperspectral imaging via DMD-based scanning
This provides a cost-effective, fast, and robust hyperspectral imaging solution for applications requiring simultaneous spectral and RGB data capture, though it appears incremental in design.
The authors tackled the problem of pushbroom hyperspectral imaging by developing a device with no macro moving parts, using a DMD and dual CMOS sensors, resulting in a prototype that captures a 192x192 pixel spatial resolution and 500 spectral bands in under 30 seconds.
We describe a new pushbroom hyperspectral imaging device that has no macro moving part. The main components of the proposed hyperspectral imager are a digital micromirror device (DMD), a CMOS image sensor with no filter as the spectral sensor, a CMOS color (RGB) image sensor as the auxiliary image sensor, and a diffraction grating. Using the image sensor pair, the device can simultaneously capture hyperspectral data as well as RGB images of the scene. The RGB images captured by the auxiliary image sensor can facilitate geometric co-registration of the hyperspectral image slices captured by the spectral sensor. In addition, the information discernible from the RGB images can lead to capturing the spectral data of only the regions of interest within the scene. The proposed hyperspectral imaging architecture is cost-effective, fast, and robust. It also enables a trade-off between resolution and speed. We have built an initial prototype based on the proposed design. The prototype can capture a hyperspectral image datacube with a spatial resolution of 192x192 pixels and a spectral resolution of 500 bands in less than thirty seconds.