Sharing of Shortwave Infrared Data (WorldView3 SWIR) in Fire Areas——Taking Wildfires in the Western United States as an Example
1. Preface
Since 2020, there have been many forest fires at home and abroad. The domestic fire is the representative Muli fire, and the wild fires in the western United States are currently intensifying abroad. At the same time, the Pantanal wetlands in South America and Brazil are also being affected by fires. Other areas such as France, Some areas of countries such as Greece and Syria have also suffered forest fires.
At present, the smog belt of wildfires in the western United States has spread to the Pacific Ocean. What kind of impact it will have on the global climate is still unknown:
2. WorldView3 SWIR sharing
Shortwave infrared has unique advantages in fire monitoring. The commonly used free remote sensing satellites that carry shortwave infrared sensors include Sentinel-2A/B and Landsat8 OLI. As the most advanced commercial satellite in the world, WorldView3 has the ability to acquire 8 shortwave bands. , The following will share WorldView3 SWIR data of a scene in Healdsburg, California.
Address link: https://pan.baidu.com/s/1hE7uuRMt7SCic-gfst_Qgg Extraction code: 79vf
The figure is the center wavelength of the band 8 of WorldView3 SWIR:
SWIR while having a strong ability to penetrate smoke, the smoke thick in certain areas, but also difficult shortwave infrared, such as identification of the hexagon in the figure,
the The picture shows the display effect of different combinations of WorldView3 SWIR:
For buildings, it may be a color in visible light, but may be different in short-wave infrared characteristics. For example, the building in the red marked area in the picture below:
In addition, this area is the same The time period Sentinel-2 also happened to pass, and the shooting time was only about 30 seconds between the two:
the picture below is the Sentinel-2 band:
students who want to compare Sentinel-2 and WorldView3 can go to ESA to download the data by themselves. If the disk capacity is full, Sentinel-2 data will not be provided this time. Today, we will use sentinel-hub to look at the Sentinel-2 data for this day:
Compare WorldView3:
Three, Sentinel-hub
Sentinel-hub provides users with the display function of real-time data and historical data. It can not only display the combined display effects of multiple bands, but also provides online browsing of indexes such as NDVI.
The Sentinel-hub in the western region of the United States below is viewed in true color: the yellow line is the strip-scan imaging area on September 9, 2020.
The Sentinel-hub in the western region of the United States below is shortwave + near-infrared viewing: the ability of shortwave to penetrate smoke, yes Clearly see the fire line of multiple fire sites
. The newly launched data is compared with historical data. This is the comparison of yesterday’s new auction. The data on September 9 clearly shows the increase in the fire area:
the picture below shows the mushroom-shaped fire site that went viral on social media. Area:
Several other fire areas:
Okay, that's it for today's introduction, blog address: https://blog.csdn.net/qq_46071146
