The Science and Technology team at Geosys has been working on advanced processing techniques for Landsat 8 for several years – giving our customers a distinct advantage over the competition. We don’t wait for the industry … we lead the way.
In 2016, Geosys began offering an enhanced version of Landsat 8 NDVI maps. While the satellite delivers at 30-meter resolution, it is also capturing some data at 15-meter resolution. By understanding the data available on the various bands and running calculations, we can accurately enhance the imagery to deliver the data at 15- meter resolution without any distortions.
This process has been verified and validated by historical imagery captured of the same location on the same day by both Landsat 8 and Sentinel 2 (which operates at 10-meter resolution).
The Basic Principle
Landsat 8 has eleven different bands that measure radiances at various spectral ranges. While most operate at 30-meter resolution, the panchromatic band is collecting data at 15-meter resolution. The panchromatic band operates at a higher spectral resolution because it has a broader spectral range. So, it has a high level of detail but the image is greyscale. We need the color, which is why the panchromatic band hasn’t been used in the past.
Geosys has defined a process, using spectral and panchromatic bands, to enhance the spatial resolution of the NDVI maps while maintaining the quality of the data.
Here is an example of the results of this new process:
The image set below shows a field in Iowa taken with Landsat 8 – the image on the left is the standard resolution while the image on the right is the enhanced, 15 meter resolution
Landsat 8 at 30 meters
Landsat 8 enhanced to 15 meters
Another comparison of Landsat 8 at 30-meters (left) verse the enhanced 15- meter resolution (right)
Within the image processing industry, there is a well-known approach called Pan Sharpening. It is important to note that this is different from the Geosys processes explained above. Pan Sharpening is pixel-level fusion technique that we have found to create radiometric distortions, which ultimately effects the quality of the data being provided. Therefore, we have worked on this alternative method to enhance the resolution of the data.
Want to learn more?
To understand more about the spectral bands and resolutions, be sure to review 4 Things You Should Know About Satellite Technology or download the complete whitepaper: Understanding and Evaluating Satellite Remote Sensing Technology in Agriculture