Descargar Sentinel-2 Level 1 y Level 2 con ESA Copernicus

Summary

The video explains how to download Sentinel-2 satellite imagery from the Copernicus platform, emphasizing its key features, including spatial resolution, spectral bands, and temporal coverage. Sentinel-2 provides 10-meter resolution for four bands, and 20- and 60-meter resolution for others, offering frequent, global coverage every five days. The video compares Sentinel-2 to other satellites like MODIS, Landsat, and ASTER in terms of their capabilities. Additionally, it guides viewers through the process of creating an account, selecting appropriate products, and downloading images, including level 1 and level 2 corrected data, with practical tips for atmospheric correction and mosaicking images for improved analysis.

Takeaways

• 😀 Sentinel-2 satellites are launched by the European Space Agency and offer multi-spectral imaging with various spatial resolutions (10m, 20m, 60m).
• 😀 Sentinel-2 has twin satellites, Sentinel-2A and Sentinel-2B, orbiting in opposite poles, providing a temporal resolution of 5 days for global coverage.
• 😀 Sentinel-2 has 13 spectral bands in total, including visible, infrared, and shortwave infrared bands, while other satellites like MODIS and Landsat have more or fewer bands.
• 😀 The best spatial resolution for Sentinel-2 is 10 meters, which is more detailed than MODIS or Landsat, which have resolutions ranging from 15m to 250m.
• 😀 Sentinel-2 is equipped with multispectral bands, which are better for detailed analysis of the Earth's surface compared to thermal bands found in MODIS or Landsat.
• 😀 MODIS has a daily revisit time, while Sentinel-2 can provide data every 5 days thanks to its twin satellites, which is ideal for monitoring changes over time.
• 😀 When performing analysis with Sentinel-2 data, understanding the resolution of the bands (10m, 20m, 60m) is critical to choosing the right bands for the analysis.
• 😀 The processing levels of Sentinel-2 data are categorized into Level-0 (raw), Level-1 (top of the atmosphere reflectance), and Level-2 (surface reflectance with atmospheric corrections).
• 😀 To convert Sentinel-2 data from Level-1 to Level-2, atmospheric correction tools like SNAP and the Sen2Cor plugin are used.
• 😀 Sentinel-2 data can be downloaded from the Copernicus project website, where users can select the area, time period, and specific satellite (2A or 2B), as well as the processing level (Level-1 or Level-2).

Q & A

What is the Sentinel 2 satellite and what is its main purpose?

Sentinel 2 is a satellite launched by the European Space Agency as part of the Copernicus program. Its main purpose is to provide high-resolution optical imagery for environmental monitoring, including agriculture, forestry, and land use.

What is the spatial resolution of Sentinel 2 and why is it important?

Sentinel 2 has a spatial resolution of 10 meters for some bands, with others having resolutions of 20 meters and 60 meters. This resolution allows for detailed monitoring of the Earth's surface, making it ideal for tasks like land use mapping and vegetation analysis.

How do Sentinel 2A and 2B satellites work together?

Sentinel 2A and 2B are twin satellites that orbit in opposite poles, with a temporal resolution of 10 days. Together, they provide more frequent observations of the Earth's surface, reducing the time gap between image captures to 5 days for the same area.

What are the different spectral bands available on Sentinel 2?

Sentinel 2 offers 13 spectral bands, including bands for visible light (RGB), near-infrared, shortwave infrared, and medium infrared. Some bands have a resolution of 10 meters, others 20 meters, and some 60 meters.

How does Sentinel 2 compare to other satellites like MODIS, Landsat 7, and Landsat 8?

While MODIS provides a large number of spectral bands (36), it has a lower spatial resolution (250 meters). Landsat 7 and 8 provide better spatial resolution (15 meters) but fewer bands. Sentinel 2 offers a balanced solution with a high spatial resolution of 10 meters and 13 spectral bands, ideal for detailed land analysis.

What is the significance of the temporal resolution of Sentinel 2?

The temporal resolution of Sentinel 2 is 5 days, thanks to its twin satellites. This is crucial for providing frequent updates for time-sensitive applications like crop monitoring, forest health assessment, and disaster response.

What is the difference between Level 1 and Level 2 Sentinel 2 data?

Level 1 data are raw images with atmospheric reflectance, whereas Level 2 data are corrected for atmospheric interference, providing surface reflectance data. Level 2 data are ideal for more precise environmental analysis.

How can users correct Sentinel 2 data from Level 1 to Level 2?

Level 1 data can be converted to Level 2 through atmospheric correction using software like SNAP and plugins like Sen2Cor, which adjusts the reflectance values to account for atmospheric effects.

How does Sentinel 2 handle cloud cover in images?

Sentinel 2 images can be processed to reduce cloud interference. By combining images from different dates, users can create mosaics where the clouds are minimized, allowing for clearer observations of the Earth's surface.

How can users download Sentinel 2 data from the Copernicus platform?

Users can create an account on the Copernicus website, use a map interface to select a region of interest, choose Sentinel 2 as the platform, and apply filters for the desired data (e.g., cloud cover, product level). Once selected, they can add the data to their cart and download it.