What is the panchromatic band, and what are the advantages?
The panchromatic sensor, found on the RedEdge-P and the Altum-PT, is sensitive to all colors in the visible through near-infrared spectrum. The panchromatic sensor enables higher resolution without large lenses and imagers for each of the multispectral bands, which optimizes the camera's weight and minimizes data volume.
How does pan sharpening work?
Pan sharpening uses a higher-resolution panchromatic image fused with lower-resolution multiband images to create a higher-resolution raster dataset. There are many proven methods for pan sharpening (which we won’t cover here).
RedEdge-P or Altum-PT will have the best spectral accuracy at the original multispectral resolution. Some pan-sharpening methods are better than others at preserving spectral quality, and in the case of RE-P and AL-PT, the multispectral bands do not cover the full panchromatic band because there are gaps between the multispectral bands. This means that there may be spectral information between multi-spectral bands that the panchromatic imager measures but the multi-spectral imagers do not. We have found that in practice, for many vegetation tasks, this difference is not significant.
The spatial resolution increase after pan-sharpening enables a host of applications that require higher spatial resolutions, such as AI/ML based methods for classification, counting, and methods where 3D information from the point cloud can be used.
If the panchromatic band senses the full visible light spectrum, why does the image look black & white?
The panchromatic bands found in the RedEdge-P and Altum-PT are monochromatic imagers, not RGB. These imagers do capture a wide bandwidth of visible light information, but the image preview will be in black & white – just like the multispectral images.
What are the applications of the panchromatic band? Can it see things which other sensors cannot?
The major advantage of the panchromatic band in the RedEdge-P and Altum-PT is that it enables higher resolution imagery without the need for larger, more expensive lenses and imagers for each multispectral band. Being able to visualize your data at leaf-level resolution opens a whole new level of analysis and insights.
The panchromatic band senses a wide range of visible light at high resolution, compared to the narrow band filters of the multispectral bands.
How do I process the images from RedEdge-P and Altum-PT?
The exact workflow depends on what software application you use for processing MicaSense imagery. We have guides available for both Agisoft Metashape and Pix4D here:
Does the pan sharpening happen in the camera?
No. There are no image processing techniques applied to the images in the camera. The pan sharpening happens entirely in post-processing, using the raw data captured from the cameras.