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    • By European Space Agency
      The fourth satellite for the Copernicus Sentinel-1 mission, Sentinel-1D, has arrived at Félix Eboué airport, the main airport in French Guiana. From there the spacecraft, safely stored in its protective casing, will be transported to launch preparation facilities at the European Spaceport in Kourou.
      View the full article
    • By NASA
      NASA science and American industry have worked hand-in-hand for more than 60 years, transforming novel technologies created with NASA research into commercial products like cochlear implants, memory-foam mattresses, and more. Now, a NASA-funded device for probing the interior of storm systems has been made a key component of commercial weather satellites.
      The novel atmospheric sounder was originally developed for NASA’s TROPICS (short for Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of SmallSats), which launched in 2023. Boston-based weather technology company Tomorrow.io integrated the same instrument design into some of its satellites.
      NASA’s TROPICS instrument. TROPICS pioneered a novel, compact atmospheric sound now flying aboard a fleet of commercial small satellites created by the weather technology company Tomorrow.io.Credit: Blue Canyon Technologies Atmospheric sounders allow researchers to gather data describing humidity, temperature, and wind speed — important factors for weather forecasting and atmospheric analysis. From low-Earth orbit, these devices help make air travel safer, shipping more efficient, and severe weather warnings more reliable.
      Novel tools for Observing Storm Systems
      In the early 2000s, meteorologists and atmospheric chemists were eager to find a new science tool that could peer deep inside storm systems and do so multiple times a day. At the same time, CubeSat constellations (groupings of satellites each no larger than a shoebox) were emerging as promising, low-cost platforms for increasing the frequency with which individual sensors could pass over fast-changing storms, which improves the accuracy of weather models.
      The challenge was to create an instrument small enough to fit aboard a satellite the size of a toaster, yet powerful enough to observe the innermost mechanisms of storm development. Preparing these technologies required years of careful development that was primarily supported by NASA’s Earth Science Division.
      William Blackwell and his team at MIT Lincoln Laboratory in Cambridge, Massachusetts, accepted this challenge and set out to miniaturize vital components of atmospheric sounders. “These were instruments the size of a washing machine, flying on platforms the size of a school bus,” said Blackwell, the principal investigator for TROPICS. “How in the world could we shrink them down to the size of a coffee mug?”
      With a 2010 award from NASA’s Earth Science Technology Office (ESTO), Blackwell’s team created an ultra-compact microwave receiver, a component that can sense the microwave radiation within the interior of storms.
      The Lincoln Lab receiver weighed about a pound and took up less space than a hockey puck. This innovation paved the way for a complete atmospheric sounder instrument small enough to fly aboard a CubeSat. “The hardest part was figuring out how to make a compact back-end to this radiometer,” Blackwell said. “So without ESTO, this would not have happened. That initial grant was critical.”
      In 2023, that atmospheric sounder was sent into space aboard four TROPICS CubeSats, which have been collecting torrents of data on the interior of severe storms around the world.
      Transition to Industry
      By the time TROPICS launched, Tomorrow.io developers knew they wanted Blackwell’s microwave receiver technology aboard their own fleet of commercial weather satellites. “We looked at two or three different options, and TROPICS was the most capable instrument of those we looked at,” said Joe Munchak, a senior atmospheric data scientist at Tomorrow.io.
      In 2022, the company worked with Blackwell to adapt his team’s design into a CubeSat platform about twice the size of the one used for TROPICS. A bigger platform, Blackwell explained, meant they could bolster the sensor’s capabilities.
      “When we first started conceptualizing this, the 3-unit CubeSat was the only game in town. Now we’re using a 6-unit CubeSat, so we have room for onboard calibration,” which improves the accuracy and reliability of gathered data, Blackwell said.
      Tomorrow.io’s first atmospheric sounders, Tomorrow-S1 and Tomorrow-S2, launched in 2024. By the end of 2025, the company plans to have a full constellation of atmospheric sounders in orbit. The company also has two radar instruments that were launched in 2023 and were influenced by NASA’s RainCube instrument — the first CubeSat equipped with an active precipitation radar.
      More CubeSats leads to more accurate weather data because there are more opportunities each day — revisits — to collect data. “With a fleet size of 18, we can easily get our revisit rate down to under an hour, maybe even 40 to 45 minutes in most places. It has a huge impact on short-term forecasts,” Munchak said.
      Having access to an atmospheric sounder that had already flown in space and had more than 10 years of testing was extremely useful as Tomorrow.io planned its fleet. “It would not have been possible to do this nearly as quickly or nearly as affordably had NASA not paved the way,” said Jennifer Splaingard, Tomorrow.io’s senior vice president for space and sensors.
      A Cycle of Innovation
      The relationship between NASA and industry is symbiotic. NASA and its grantees can drive innovation and test new tools, equipping American businesses with novel technologies they may otherwise be unable to develop on their own. In exchange, NASA gains access to low-cost data sets that can supplement information gathered through its larger science missions.
      Tomorrow.io was among eight companies selected by NASA’s Commercial SmallSat Data Acquisition (CSDA) program in September 2024 to equip NASA with data that will help improve weather forecasting models. “It really is a success story of technology transfer. It’s that sweet spot, where the government partners with tech companies to really take an idea, a proven concept, and run with it,” Splaingard said.
      By Gage Taylor
      NASA’s Goddard Space Flight Center, Greenbelt, Md.
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      Last Updated Sep 02, 2025 Related Terms
      Earth Hurricanes & Typhoons TROPICS (Time-Resolved Observations of Precipitation Structure and Storm Intensity with a Constellation of Smallsats) View the full article
    • By NASA
      NASA’s IMAP (Interstellar Mapping and Acceleration Probe) mission will map the boundaries of the heliosphere, the bubble created by the solar wind that protects our solar system from cosmic radiation. Credit: NASA/Princeton/Patrick McPike NASA will hold a media teleconference at 12 p.m. EDT on Thursday, Sept. 4, to discuss the agency’s upcoming Sun and space weather missions, IMAP (Interstellar Mapping and Acceleration Probe) and Carruthers Geocorona Observatory. The two missions are targeting launch on the same rocket no earlier than Tuesday, Sept. 23.
      The IMAP mission will map the boundaries of our heliosphere, the vast bubble created by the Sun’s wind that encapsulates our entire solar system. As a modern-day celestial cartographer, IMAP will explore how the heliosphere interacts with interstellar space, as well as chart the range of particles that fill the space between the planets. The IMAP mission also will support near real-time observations of the solar wind and energetic particles. These energetic particles can produce hazardous space weather that can impact spacecraft and other NASA hardware as the agency explores deeper into space, including at the Moon under the Artemis campaign.
      NASA’s Carruthers Geocorona Observatory will image the ultraviolet glow of Earth’s exosphere, the outermost region of our planet’s atmosphere. This data will help scientists understand how space weather from the Sun shapes the exosphere and ultimately impacts our planet. The first observation of this glow – called the geocorona – was captured during Apollo 16, when a telescope designed and built by George Carruthers was deployed on the Moon.
      Audio of the teleconference will stream live on the agency’s website at:
      https://www.nasa.gov/live
      Participants include:
      Nicky Fox, associate administrator, Science Mission Directorate, NASA Headquarters in Washington Teresa Nieves-Chinchilla, director, Moon to Mars Space Weather Analysis Office, NASA’s Goddard Space Flight Center in Greenbelt, Maryland David J. McComas, IMAP principal investigator, Princeton University Lara Waldrop, Carruthers Geocorona Observatory principal investigator, University of Illinois Urbana-Champaign To participate in the media teleconference, media must RSVP no later than 11 a.m. on Sept. 4 to Sarah Frazier at: sarah.frazier@nasa.gov. NASA’s media accreditation policy is available online.
      The IMAP and Carruthers Geocorona Observatory missions will launch on a SpaceX Falcon 9 rocket from Launch Complex 39A at NASA’s Kennedy Space Center in Florida. Also launching on this flight will be the National Oceanic and Atmospheric Administration’s (NOAA) Space Weather Follow On – Lagrange 1 (SWFO-L1), which will monitor solar wind disturbances and detect and track coronal mass ejections before they reach Earth.
      David McComas, professor, Princeton University, leads the IMAP mission with an international team of 27 partner institutions. The Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, built the spacecraft and will operate the mission. NASA’s IMAP is the fifth mission in NASA’s Solar Terrestrial Probes Program portfolio.
      The Carruthers Geocorona Observatory mission is led by Lara Waldrop from the University of Illinois Urbana-Champaign. Mission implementation is led by the Space Sciences Laboratory at University of California, Berkeley, which also designed and built the two ultraviolet imagers. BAE Systems designed and built the Carruthers spacecraft.
      The Solar Terrestrial Probes Program Office, part of the Explorers and Heliophysics Project Division at NASA Goddard, manages the IMAP and Carruthers Geocorona Observatory missions for NASA’s Science Mission Directorate.
      NASA’s Launch Services Program, based at NASA Kennedy, manages the launch service for the mission.
      To learn more about IMAP, please visit:
      https://www.nasa.gov/imap
      -end-
      Abbey Interrante / Karen Fox
      Headquarters, Washington
      301-201-0124 / 202-358-1600
      abbey.a.interrante@nasa.gov / karen.c.fox@nasa.gov
      Sarah Frazier
      Goddard Space Flight Center, Greenbelt, Md.
      202-853-7191
      sarah.frazier@nasa.gov
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      Last Updated Aug 28, 2025 EditorJessica TaveauLocationNASA Headquarters Related Terms
      Heliophysics Carruthers Geocorona Observatory (GLIDE) Goddard Space Flight Center Heliophysics Division Heliosphere IMAP (Interstellar Mapping and Acceleration Probe) Kennedy Space Center Launch Services Program Science Mission Directorate Solar Terrestrial Probes Program View the full article
    • By NASA
      5 min read
      Astronomers Map Stellar ‘Polka Dots’ Using NASA’s TESS, Kepler
      Scientists have devised a new method for mapping the spottiness of distant stars by using observations from NASA missions of orbiting planets crossing their stars’ faces. The model builds on a technique researchers have used for decades to study star spots.
      By improving astronomers’ understanding of spotty stars, the new model — called StarryStarryProcess — can help discover more about planetary atmospheres and potential habitability using data from telescopes like NASA’s upcoming Pandora mission.
      “Many of the models researchers use to analyze data from exoplanets, or worlds beyond our solar system, assume that stars are uniformly bright disks,” said Sabina Sagynbayeva, a graduate student at Stony Brook University in New York. “But we know just by looking at our own Sun that stars are more complicated than that. Modeling complexity can be difficult, but our approach gives astronomers an idea of how many spots a star might have, where they are located, and how bright or dark they are.”
      A paper describing StarryStarryProcess, led by Sagynbayeva, published Monday, August 25, in The Astrophysical Journal.
      Watch to learn how a new tool uses data from exoplanets, worlds beyond our solar system, to tell us about their polka-dotted stars.
      NASA’s Goddard Space Flight Center
      Download images and videos through NASA’s Scientific Visualization Studio.

      NASA’s TESS (Transiting Exoplanet Survey Satellite) and now-retired Kepler Space Telescope were designed to identify planets using transits, dips in stellar brightness caused when a planet passes in front of its star.
      These measurements reveal how the star’s light varies with time during each transit, and astronomers can arrange them in a plot astronomers call a light curve. Typically, a transit light curve traces a smooth sweep down as the planet starts passing in front of the star’s face. It reaches a minimum brightness when the world is fully in front of the star and then rises smoothly as the planet exits and the transit ends.  
      By measuring the time between transits, scientists can determine how far the planet lies from its star and estimate its surface temperature. The amount of missing light from the star during a transit can reveal the planet’s size, which can hint at its composition.
      Every now and then, though, a planet’s light curve appears more complicated, with smaller dips and peaks added to the main arc. Scientists think these represent dark surface features akin to sunspots seen on our own Sun — star spots.
      The Sun’s total number of sunspots varies as it goes through its 11-year solar cycle. Scientists use them to determine and predict the progress of that cycle as well as outbreaks of solar activity that could affect us here on Earth.
      Similarly, star spots are cool, dark, temporary patches on a stellar surface whose sizes and numbers change over time. Their variability impacts what astronomers can learn about transiting planets.
      Scientists have previously analyzed transit light curves from exoplanets and their host stars to look at the smaller dips and peaks. This helps determine the host star’s properties, such as its overall level of spottiness, inclination angle of the planet’s orbit, the tilt of the star’s spin compared to our line of sight, and other factors. Sagynbayeva’s model uses light curves that include not only transit information, but also the rotation of the star itself to provide even more detailed information about these stellar properties.
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      This artist’s concept illustrates the varying brightness of star with a transiting planet and several star spots. NASA’s Goddard Space Flight Center “Knowing more about the star in turn helps us learn even more about the planet, like a feedback loop,” said co-author Brett Morris, a senior software engineer at the Space Telescope Science Institute in Baltimore. “For example, at cool enough temperatures, stars can have water vapor in their atmospheres. If we want to look for water in the atmospheres of planets around those stars — a key indicator of habitability — we better be very sure that we’re not confusing the two.”
      To test their model, Sagynbayeva and her team looked at transits from a planet called TOI 3884 b, located around 141 light-years away in the northern constellation Virgo.
      Discovered by TESS in 2022, astronomers think the planet is a gas giant about five times bigger than Earth and 32 times its mass.
      The StarryStarryProcess analysis suggests that the planet’s cool, dim star — called TOI 3384 — has concentrations of spots at its north pole, which also tips toward Earth so that the planet passes over the pole from our perspective.
      Currently, the only available data sets that can be fit by Sagynbayeva’s model are in visible light, which excludes infrared observations taken by NASA’s James Webb Space Telescope. But NASA’s upcoming Pandora mission will benefit from tools like this one. Pandora, a small satellite developed through NASA’s Astrophysics Pioneers Program, will study the atmospheres of exoplanets and the activity of their host stars with long-duration multiwavelength observations. The Pandora mission’s goal is to determine how the properties of a star’s light differs when it passes through a planet’s atmosphere so scientists can better measure those atmospheres using Webb and other missions.
      “The TESS satellite has discovered thousands of planets since it launched in 2018,” said Allison Youngblood, TESS project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “While Pandora will study about 20 worlds, it will advance our ability to pick out which signals come from stars and which come from planets. The more we understand the individual parts of a planetary system, the better we understand the whole — and our own.”
      Facebook logo @NASAUniverse @NASAUniverse Instagram logo @NASAUniverse By Jeanette Kazmierczak
      NASA’s Goddard Space Flight Center, Greenbelt, Md.
      Media Contact:
      Alise Fisher
      202-358-2546
      alise.m.fisher@nasa.gov
      NASA Headquarters, Washington
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      Details
      Last Updated Aug 25, 2025 Related Terms
      Astrophysics Exoplanet Atmosphere Exoplanets Galaxies, Stars, & Black Holes Galaxies, Stars, & Black Holes Research Goddard Space Flight Center Kepler / K2 Stars TESS (Transiting Exoplanet Survey Satellite) The Universe View the full article
    • By NASA
      Explore This Section Earth Earth Observer Editor’s Corner Feature Articles Meeting Summaries News Science in the News Calendars In Memoriam Announcements More Archives Conference Schedules Style Guide 9 min read
      Harmonized Landsat and Sentinel-2: Collaboration Drives Innovation
      Introduction
      Landsat, a joint program of NASA and the U.S. Geological Survey (USGS), has been an invaluable tool for monitoring changes in Earth’s land surface for over 50 years. Researchers use instruments on Landsat satellites to monitor decades-long trends, including urbanization and agricultural expansion, as well as short-term dynamics, including water use and disaster recovery. However, scientists and land managers often encounter one critical limitation of this program: Landsat has a revisit time of eight days (with Landsat 8 and 9 operating), which is too long to capture events and disasters that occur on short timescales. Floods, for example, can quickly inundate a region, and cloud cover from storms can delay Landsat’s ability to get a clear observation on damage.
      In 2015, the European Space Agency’s (ESA) Copernicus Sentinel-2A mission joined Landsat 7 and 8 in orbit. It was designed to collect comparable optical land data with the intention of leveraging Landsat’s archive. Two years later, ESA launched Sentinel-2B, a satellite identical to Sentinel-2A.
      Led by a science team at NASA’s Goddard Space Flight Center (GSFC), the USGS, NASA, and ESA began to work on combining the capabilities of Sentinel-2 and Landsat satellites. This idea was the impetus behind Harmonized Landsat and Sentinel-2 (HLS) project, a NASA initiative that created a seamless product from the Operational Land Imager (OLI) and Multi-Spectral Instrument (MSI) aboard Landsat and Sentinel-2 satellites, respectively. HLS Version 2.0 (V2.0) is the most recent version of these data and had a global median repeat frequency of 1.6 days in 2022 by combining observations from Landsat 8 and 9 and Sentinel-2A and B. The recent addition of Sentinel-2C data will provide even more frequent observations. With near-global coverage and improved harmonization algorithms, HLS V2.0 paves the way for new applications and improved land monitoring systems – see Animation 1. HLS data are available for download on NASA Earthdata: HLSL30v2.0 and HLSS30v2.0. These data can also be accessed through Google Earth Engine: HLSL30v2.0 and HLSS30v2.0. 
      Animation 1. This visualization shows the change in vegetation in Maryland from January 1 to December 30, 2016, using Normalized Difference Vegetation Index (NDVI) data from Harmonized Landsat Sentinel-2 (HLS). The visualization shows land on both sides of the Chesapeake Bay, where red represents bare soil and green indicates healthy, growing vegetation. Animation credit: Michael Taylor [Science Systems and Applications Inc. (SSAI)], Matthew Radcliff [USRA], and Jeffrey Masek [GSFC]. Caption adapted from Laura Rocchio [SSAI] The Dawn of HLS
      The story of HLS begins before the launch of Sentinel-2A in 2015. Jeffrey Masek [GSFC], who was at that time project scientist for Landsat 8, led a group of researchers who wanted to find a way to harmonize Landsat data with other satellite data. Their aim was to create a “virtual constellation” similar to how weather satellites operate.
      “HLS meets a need that people have been asking for for a long time,” said Masek.
      What began as a research question with an experimental product evolved into an operational project with the involvement of the Satellite Needs Working Group (SNWG). SNWG is an interagency effort to develop solutions that address Earth observation needs of civilian federal agencies. Every two years, SNWG conducts a survey of federal agencies to see how their work could benefit from satellite data. The answers span the gamut of application areas, from water quality monitoring to disaster recovery to planning how best to protect and use natural resources. SNWG brings these ideas to NASA, USGS, and the National Oceanic and Atmospheric Administration (NOAA) – the three main U.S. government providers of satellite data. These agencies work together to create and implement solutions that serve those needs. NASA plays a critical role in every step of the SNWG process, including leading the assessment of survey responses from over 30 federal agencies, managing and supporting the implementation of identified solutions, and encouraging solution co-design with federal partners to maximize impact.
      The HLS surface reflectance product was an outcome of the very first SNWG solution cycle in 2016. This product was expanded, following additional SNWG requests in 2020 and 2022. The 2020 cycle saw the creation of nine HLS-derived vegetation indices, and the 2022 cycle aimed for a six-hour latency product.
      The U.S. Department of Agriculture (USDA) now uses HLS to map crop emergence at the field scale in the corn belt, allowing farmers to better plan their growing seasons. Ranchers in Colorado use the dataset to decide where to graze their cattle during periods of drought. HLS also informs the use and termination of cover crops in the Chesapeake Bay area. In 2024, the Federal Emergency Management Agency (FEMA) employed HLS to identify where to focus aid in the aftermath of Hurricane Helene.
      A New and Improved HLS
      In the July 2025 issue of Remote Sensing of Environment, a team of researchers outlined the HLS V2.0 surface reflectance dataset and algorithms. The team included seven NASA co-authors, members of the 2018–2023 Landsat Science Team, and ESA. The lead author, Junchang Ju [GSFC—Remote Sensing Scientist], has been the technical lead on HLS since its inception. Co-author Christopher Neigh [GSFC—Landsat 8/9 Project Scientist] is the principal investigator on the HLS project. V2.0, which was completed in Summer 2023, incorporates several major improvements over HLS V1.4, the most recent publicly available HLS product. HLS V1.4 covered about 30% of the global land area, providing data on North America and other select locations. HLS V2.0 provides data at a spatial resolution of 30 m (98 ft) with near-global coverage from 2013 onward. The dataset includes all land masses except Antarctica. HLS V2.0 also has key algorithmic improvements in atmospheric correction, cloud masking, and bidirectional reflectance distribution function (BRDF) correction. Together, these algorithms “harmonize” the data, or ensure that the distinct Landsat and Sentinel-2 datasets can effectively be used interchangeably – see Animation 2.
      Animation 2: The visualization provides the Normalized Difference Vegetation Index (NDVI) data from Harmonized Landsat Sentinel-2 (HLS) for farm fields south of Columbus, NE. The red represents bare soil and green represents healthy, growing vegetation. The animation runs from January 1 to December 30, 2016. Animation credit: Michael Taylor [SSAI], Matthew Radcliff [USRA], and Jeffrey Masek [GSFC]. Caption adapted from Laura Rocchio [SSAI] HLS V2.0 in Action
      The increased frequency of observations improved the ability of the scientific community to track disaster recovery, changes in phenology, agricultural intensification, rapid urban growth, logging, and deforestation. Researchers are already putting these advances to use.
      The land disturbance product (DIST-ALERT) is a global land change monitoring system that uses HLS V2.0 data to track vegetation anomalies in near real-time – see Figure 1. DIST-ALERT captures agricultural expansion, urban growth, fire, flooding, logging, drought, landslides, and other forces of change to vegetation. Amy Pickens [University of Maryland, Department of Geographical Sciences—Assistant Research Professor] said that HLS is the perfect dataset for tracking disturbances because of the frequency of observations.
      DIST-ALERT was created through Observational Products for End-Users from Remote Sensing Analysis (OPERA), a project at NASA/Jet Propulsion Laboratory (JPL). OPERA products respond to agency needs identified by the SNWG. In 2018, SNWG identified tracking surface disturbance as a key need. OPERA partnered with the Global Land Analysis and Discovery (GLAD) lab at University of Maryland to develop the change detection algorithm.
      To track changes in vegetation, the DIST-ALERT system establishes a rolling baseline – meaning that for any given pixel, the vegetation cover is compared against vegetation cover from the same 31-day window in the previous three years. The primary algorithm detects any vegetation loss relative to the established baseline. A secondary algorithm flags any spectral anomaly (i.e., any change in reflectance) compared to that same baseline. This approach ensures that the algorithm catches non-vegetation change (e.g., new building or road projects in unvegetated areas). Used together, these algorithms can identify long-term changes in agricultural expansion, deforestation, and urbanization alongside short-term changes in crop harvest, drought, selective logging, and the impacts of disasters. On average, DIST-ALERT is made available on LP DAAC within six hours of when new HLS data is available. Currently, the dataset does not provide attribution to disturbances.
      Figure 1. In March 2025, wildfires burned through South Korea, resulting in heavy vegetation loss. [left] Output of the DIST-ALERT product on NASA Worldview from May 8, 2025, with vegetation loss in percent flagged with varying levels of confidence. Yellow and red represent areas with confirmed vegetation cover losses of right] Natural-color image captured by the Multi-Spectral Instrument (MSI) aboard Sentinel-2C on May 8, 2025. The large brown burn scar in the center of the image corresponds to vegetation loss detected by DIST-ALERT. It stands in contrast to the surrounding green vegetation. Figure credit: NASA Earthdata Disturbance alerts already exist in some ecosystems. Brazil’s National Institute for Space Research [Instituto Nacional de Pesquisas Espaciais (INPE)] runs two projects that detect deforestation in the Amazon: Programa de Cálculo do Desflorestamento da Amazônia (PRODES) and Sistema de Detecção de Desmatamento em Tempo Real (DETER). The GLAD lab created its own forest loss alerts – GLAD-L and GLAD-S2 – using Landsat and Sentinel-2 data respectively. Global Forest Watch integrates GLAD-L and GLAD-S2 data with Radar for Detecting Deforestation (RADD) observations – derived from synthetic aperture radar data from Copernicus Sentinel-1 – into an integrated deforestation alert.
      The implementation of these alert systems, some of which have been around for decades, have been shown to impact deforestation rates in the tropics. For example, a 2021 study in Nature Climate Change found that deforestation alerts decreased the probability of deforestation in Central Africa by 18% relative to the average 2011–2016 levels.
      DIST-ALERT is distinct from other alert systems in a few ways. First, it has global coverage. Second, the rolling baseline allows for tracking changes in seasonality and disturbances to dynamic ecosystems. When HLS V2.0 data are input to DIST-ALERT, the system is also better at identifying disturbances in cloudy ecosystems than other individual alert systems – because it is more likely to obtain clear observations. This also enables it to identify the start and end of the disturbance more precisely.
      Pickens said that the DIST-ALERT team is already working with end-users who are implementing their data product. She has spoken to some who use the system to help logging companies prove that they are complying with regulations. The U.S. Census Bureau is also using DIST-ALERT to monitor fast-growing communities so that they can do targeted assessments in the interim between the larger decennial census.
      Alongside DIST-ALERT, OPERA has also been developing the Dynamic Surface Water eXtent (DSWx) product suite, which employs HLS to track surface water (e.g., lakes, reservoirs, rivers, and floods) around the globe – see Figure 2. These new products represent the new applications made possible by the HLS interagency and international collaboration.
      Figure 2. The map shows flood extent and estimates of flood depth in areas west of Porto Alegre, Brazil on May 6, 2024. The flood extent is from the Observational Products for End-Users from Remote Sensing Analysis (OPERA) Dynamic Surface Water eXtent product, which uses Harmonized Landsat Sentinel-2 data. The flood depth estimate is from the Floodwater Depth Estimation Tool (FwD ET). The darkest blue areas represent floodwater at least 5 m (20 ft) deep. Much of the inundated floodplain is light blue, which equates to depths of between 0.1–1 m (4–40 in). Figure credit: Lauren Dauphin [NASA’s Earth Observatory], Dinuke Munasinghe [JPL], Sagy Cohen [University of Alabama], and Alexander Handwerger [JPL] Conclusion
      HLS is set to continue improving land monitoring efforts across the globe. Meanwhile, the HLS science team is working to improve the algorithms for a more seamless harmonization of Landsat 8 and 9 and Sentinel-2 data. They are also working to improve the cloud-masking algorithm, have recently released vegetation indices, and are working on developing a low-latency (six-hour) HLS surface reflectance product, all while incorporating user feedback.
      Looking ahead, the launch of future Sentinel and Landsat satellites will further the development of HLS. The additional data and unique capabilities will continue to meet researchers’ need for more frequent, high-quality satellite observations of Earth’s land surface.
      Madeleine Gregory
      NASA’s Goddard Space Flight Center/Science Systems and Applications Inc.
      madeleine.s.gregory@nasa.gov
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      Last Updated Aug 25, 2025 Related Terms
      Earth Science View the full article
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