Unlocking clearer views of our water worlds: A Landsat legacy

A study highlights the significant advancements in water environment analysis facilitated by the Landsat missions. This research, for the first time, offers a comprehensive global assessment of cloud-free observations (NCOs) from Landsat, underscoring its pivotal role in environmental and hydrological studies.

Satellite remote sensing is vital for monitoring marine and freshwater ecosystems, leveraging missions like SeaWiFS, MODIS, MERIS, Landsat, and Sentinel for tracking water parameters such as chlorophyll, sediment, and temperature. The dynamic nature of water bodies demands high-frequency observations for accuracy, with limitations highlighted by factors like clouds and sunglint. Despite its longer revisit cycle, Landsat's observations are invaluable for inland and coastal waters, emphasizing the need for more frequent data to effectively monitor the dynamic changes in aquatic ecosystems.

A recent study (doi: 10.34133/remotesensing.0110) published in the Journal of Remote Sensing on 22 February 2024, advancements in analyzing water environments via Landsat missions are revealed. For the first time, this research offers a global assessment of cloud-free observations (NCOs) from Landsat, emphasizing its critical contribution to environmental and hydrological studies, marking a significant leap in our capability to monitor and understand water bodies on a global scale.

The study embarked on an ambitious journey to unravel the intricacies of NCOs via the Landsat missions. By meticulously analyzing over 4.8 million Landsat images spanning from Landsat 5 through Landsat 8, they uncovered striking spatial and temporal variations in cloud-free data across the globe. Their research illustrated Landsat-8's superior performance, offering nearly double the mean annual NCOs compared to its predecessors. This leap in data quality is particularly pronounced in areas with orbital overlaps, especially above the 45°N latitude, where observation quality is significantly enhanced. Furthermore, this work delves into the vital role of these overlaps in augmenting the quantity and quality of observations, presenting a game-changer in how we monitor and understand the dynamics of the Earth's water environments.

The study's lead researcher emphasized, "Our analysis not only showcases Landsat-8's superior capability in providing nearly twice as many mean annual NCOs as its predecessors but also highlights the importance of adjacent orbit overlaps in improving observation quality, particularly above 45°N latitude."

The findings hold profound implications for enhancing the accuracy of long-term environmental change detection and monitoring. By leveraging improved NCOs, researchers and policymakers can make more informed decisions, particularly in managing water resources and addressing ecological challenges.

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References

DOI

10.34133/remotesensing.0110

Original Source URL

https://doi.org/10.34133/remotesensing.0110

Funding information

This work was supported by the National Natural Science Foundation of China (nos. 42271322 and 42321004) and Guangdong Provincial Higher Education Key Technology Innovation Project (2020ZDZX3006).

About Journal of Remote Sensing

The Journal of Remote Sensing, an online-only Open Access journal published in association with AIR-CAS, promotes the theory, science, and technology of remote sensing, as well as interdisciplinary research within earth and information science.