For over 60 years humans have been putting cameras and sensors into space to look back at our planet. Satellites capture data across the electromagnetic spectrum — from visible wavelengths all the way to radio wavelengths. This is called Earth Observation (EO) data.
Here at SkyWatch, we provide access to Earth Observation data so you can build valuable applications in the industries that you serve, whether they are agriculture, insurance, or financial services.
Here are some of the types of data used in Earth Observation.
One of the most common types of earth observation data outputs is what we call true color composite. This is the combination of a red, green, and blue band from a multispectral imager pressed together to create a true color image. This image looks no different than any image you would see on Google Earth or any other mapping service you use.
The most common use case for true color composite imagery is to view change in an area or monitor an area's development over time. This includes construction site monitoring, mining site monitoring, or deforestation monitoring, among many other use cases.
Another popular type of earth observation data is a false color composite. This is a type of satellite product that includes or displays features that are invisible to the human eye. Such features include minerals, healthy vegetation, burnt ground, and soil moisture.
Some of the use cases and benefits of false color composite include monitoring crop health using near-infrared bands. Infrared bands show vegetation regrowth over time after wildfire or after detecting pollution in the soil from a nearby power plant or mining facility. The use cases for false color composite span dozens of different industries.
Monitoring Crop Health Through Indexes
In earth observation, it is also very popular to use the bands from a multispectral sensor to create what we call indexes. Indexes are used to better discriminate the differences between features and highlight changes over time in a particular area.
The most common index is the Normalized Vegetation Differential Index, otherwise known as NDVI. Some of the use cases or benefits of an NDVI satellite product include monitoring crops' health to optimize fertilizer and water usage, identifying crops attacked by pests and diseases, and assessing the impact of a wildfire. This is achieved through Normalized Burn Ratio Index, also called NBRI.
Thermal imaging is another popular form of earth observation data used to measure the temperature variation of something on the ground. Thermal imaging is also used if we need to see through obscurity created by either cloud, smoke, or other limiters. For example the ability to monitor a wildfire through the smoke the fire created.
Another example is being able to detect heat by monitoring the rate at which water evaporates from the ground. Imagine a wildfire raging, creating massive amounts of smoke in the sky. In earth observation, the way we monitor that wildfire is by using a thermal infrared sensor. That sensor allows us to view the heat that is emitted from those fires through the clouds.
Shortwave Infrared, also known as SWIR, is the type of imaging in earth observation that allows us to:
- Penetrate thin clouds
- Identify interesting minerals and new dig sites
- Identify new illegal constructions quicker in areas often covered by clouds
- Detect oil spills next to pipelines and other oil infrastructure
Synthetic Aperture Radar, also known as SAR, is a type of earth observation data collection that allows us to peer through clouds and image our planet day and night. This can be used for monitoring floods in near real-time, tracking ground deformation, and mapping volcanic eruptions.
Over 70% of the world's landmass is covered by clouds, which makes it very difficult for most satellites to image our planet. SAR provides high or low-resolution imaging capabilities day and night and in a way that is weather independent. That's right, it can see through the clouds! Radar satellites are particularly well suited for surveillance of vast lands with limited above-ground, distinct features such as glaciers and deserts.