Blog | Descartes Labs

Get to Know Marigold (Part 2): Introduction to the Bare Earth Composites

Written by Descartes Labs | Sep 11, 2024

Welcome to Marigold! This is part 2 of our Get to Know Marigold blog series with helpful videos. This series gives you and insiders' view of Marigold. Part 1 of this series can be found here: Functionality and Processing Tools

In the following video snippets, we will introduce you to our proprietary data sets - the Descartes Labs Bare Earth Composites. 

Video: Overview of the Bare Earth Composite


Accessing the best remote sensing data for mineral exploration can be challenging, time consuming, and require a specialist’s knowledge. We have combed through the entire archives of ASTER and Sentinel-2 satellite imagery to create global, analysis-ready Bare Earth Composites to provide the best data possible for geological interpretation.

 

Video: Pixel Inspector


To create these, Descartes Labs used Machine Learning algorithms to find the “barest” pixel for the entire archive of ASTER and Sentinel-2 data. These are the pixels with the least vegetation, water, cloud, shadow, snow and ice so that the data is optimized for exposed outcrop. 

 

Sentinel-2/ASTER Data Processing, Before and After Mosaic


Descartes Labs corrects the selected pixels to surface reflectance and then mosaics these pixels together to create a seamless global composite. The imagery is then spectrally balanced so you can process regional areas with ease. 

The Bands that make up the Bare Earth Composites

We then took an additional step to provide you with our Fused Bare Earth Composite, combining the best spectral bands from Sentinel-2 and ASTER sensors for mineral exploration. We merged the 9 visible-to-near-infrared bands from Sentinel-2 and the 6 short-wave-infrared bands from ASTER to create a single spectral dataset to provide you 15 wavelengths of light for a greater spectral resolution. This data is ideal for regional exploration, mineral mapping or lithological discrimination with spatial resolutions for bands at 10, 20 and 30 meters. 

Video: Adding Bare Earth Composite


To access the Descartes Labs Fused Bare Earth Composite, first, log in to your Marigold account. Then, in the Raster Layers section, click on the plus sign and Catalog Layer. Select the Fused Bare Earth Composite option and click Add Layer. Next, choose your area of interest and adjust your parameters. Use the magic wand icon to auto-scale the layers. You can now explore your areas of interest!

In the next upcoming series of Get to Know Marigold, you will learn how to use Descartes Labs’ Bare Earth Composites to make your data analysis faster, easier, and more efficient. Descartes Labs empowers project geologists to unlock new insights, drive informed decisions, and optimize remote sensing workflows.