Jump to content
Join the Alien Search, login or register FREE on Aliens and Space Forum
Members Can Post Anonymously On This Site

Summary of the 2023 GEDI Science Team Meeting

NASA

By NASA
in NASA

 Share

Recommended Posts

  • Publishers
NASA Mentor

NASA

Posted
  • Publishers
Posted
eo-meeting-summary-banner.png?w=1037

23 min read

Summary of the 2023 GEDI Science Team Meeting

Introduction

The 2023 Global Ecosystem Dynamics Investigation (GEDI) Science Team Meeting (STM) took place October 17–19, 2023, at the University of Maryland, College Park (UMD), in College Park, MD. Upwards of 80 people participated in the hybrid meeting (around 50 in-person and the rest virtually). Included among them were GEDI Science Team (ST) members, collaborators, and stakeholders – see Photo. The primary goals of the meeting included providing a status update on the GEDI instrument aboard the International Space Station (ISS), receiving final project updates from the inaugural cohort of the GEDI completed ST, and understanding the present status and future goals of data product development.

After a short mission status update, the remainder of this article will summarize the content of the STM. For those desiring more information on these topics, some of the full meeting presentations are posted online. Readers can also contact the GEDI ST with specific questions.

GEDI group photo
Photo. GEDI Science Team Meeting in-person and virtual attendees.
Photo credit: Talia Schwelling

Mission Status Update: GEDI Given New Lease on Life

A lot has changed since the publication of the last GEDI STM summary. (See Summary of the GEDI Science Team Meeting in the July–August 2022 issue of The Earth Observer [Volume 34, issue 4, pp. 20–24]). When the GEDI ST convened in November 2022, the fate of GEDI was hanging in the balance, with the plan being to release GEDI from the ISS at the end of its second extension period.

NASA saved the instrument, however, and a new plan went into effect: in order to extend its tenure on the ISS, the GEDI mission entered a temporary period of “hibernation” in March 2023 after nearly four years in orbit. This hibernation period and movement of the instrument from Exposed Facility Unit (EFU)-6 (operating location) to EFU-7 (storage location) made way for another mission – see Figure 1. (UPDATE: After being in storage for roughly 13 months, the GEDI instrument was returned to its original location on the Japanese Experiment Module–Exposed Facility (JEM–EF) on Earth Day this year, April 22, 2024, and is now once again back to normal science operations using its three lasers.)

GEDI figure 2
Figure 1. NASA’s GEDI instrument was moved from EFU-6 to EFU-7 on the ISS on March 17, 2023, where it remained in hibernation for 13 months until its recent reinstallation to EFU-6 on April 22, 2024. The instrument is once again back to normal science operations using its three lasers.
Figure credit: NASA

As The Earth Observer reported in 2023, data from GEDI are being used for a wide range of applications, including biomass estimation, habitat characterization, and wildfire prediction (See page 4 of The Editor’s Corner in the March–April 2023 issue of The Earth Observer [Volume 35,Issue 2, pp. 1–4]. This section also reports on GEDI’s extension via out-of-cycle Senior Review in 2022). GEDI data is used to develop maps to quantify biomass that are unique in both their accuracy and their explicit characterization of uncertainty and are a key component in the estimation of aboveground carbon stocks, as absorbed carbon is used to drive plant growth and is stored as biomass – see Figure 2. These estimations help quantify the impacts of deforestation and subsequent regrowth on atmospheric carbon dioxide (CO2) concentration. NASA’s choice to extend the GEDI mission has significantly broadened the capacity to collect more of these important data.

GEDI figure 1
Figure 2. Country-wide estimates of total aboveground biomass in petagrams (Pg) using GEDI Level-4B Version 2.1 dataset (GEDI_L4B_AGB).
Figure credit: ORNL DAAC

DAY ONE

GEDI Mission Operations, Instrument Status, and Data Level Updates

Ralph Dubayah [UMD—GEDI Principal Investigator (PI)] opened the meeting with a summary of the current status of the mission and GEDI data products. After reviewing the details of GEDI’s hibernation (described in the previous section) he went on to describe what GEDI has accomplished over the past 4.5 years of operations, noting that the instrument collected over 26 billion footprints over the land surface.

All the data collected by GEDI during its first epoch (i.e., before its hibernation) have been processed and released to the appropriate Distributed Active Archives Centers (DAACs) as Version 2 (V2) products. (To learn more about the DAACs and other aspects of Earth Science data collection and processing, see Earth Science Data Operations: Acquiring, Distributing, and Delivering NASA Data for the Benefit of Society, in the March–April 2017 issue of The Earth Observer, [Volume 29, Issue 2, pp. 4–18]. The DAACs – including URL links to each – are listed in a Table on page 7–8 of this issue). The two DAACs directly involved with GEDI data processing are the Land Processes DAAC (LP DAAC) and Oak Ridge National Laboratory (ORNL) DAAC. The LP DAAC houses GEDI Level-1 (L1) data, which consists of geolocated waveforms, and L2 data, which is broken down into L2A and L2B. L2A data includes ground elevation, canopy height, and relative height metrics. (Waveform measurements are described in detail in a sidebar on page 32 of the Summary of the Second GEDI Science Team Meeting in the November–December 2016 issue of The Earth Observer [Volume 28, Issue 6, pp. 31–36].) L2B data includes canopy cover fraction (CCF) and leaf area index (LAI). The ORNL DAAC houses GEDI L3 gridded land surface metrics data, L4A footprint level aboveground biomass density data, and L4B gridded aboveground biomass density data – e.g., see Figure 2.

Dubayah went on to explain that while GEDI hibernated, the mission team would work to enhance existing data products as well as produce new products. Version 3 (V3) datasets for all data products are expected to be released by the fall of 2024, and new data products are in development, including a waveform structural complexity index (WSCI) and a topography and canopy height product that blends data from GEDI and the Ice, Clouds, and land Elevation Satellite–2 (ICESat–2) mission. A new dataset, the GEDI L4C footprint level waveform structural complexity index (WSCI) product, was added to the ORNL DAAC catalogue in May 2024. To further improve data quality and coverage, the GEDI team is hoping to organize an airborne lidar field campaign to southeast Asia in the coming years. Dubayah concluded his updates by highlighting a set of six papers published in 2023 in Nature and Science family or partner journals that focused on the use of GEDI data. Visit our website for a comprehensive list of publications related to GEDI.

After receiving a general update from the mission PI, the next several presentations gave meeting participants a more in-depth look at GEDI science data planning and individual data products. Scott Luthcke [NASA’s Goddard Space Flight Center (GSFC)—GEDI Co-Investigator (Co-I)] presented status updates for the GEDI Science Operating Center (SOC), including the Science Planning System (SPS) and Science Data Processing System (SDPS) automation, development, and processing. In addition, he reported on the status of the L1 geolocated waveform data product and the L3 gridded land surface metrics product. At the time of this meeting, the SPS had completed operations through mission week 223 – almost 4.5 years of data – and was beginning to transition to improving processes on the back end while GEDI hibernates. The SDPS had completed processing and delivery of all V2 data products to the LP DAAC and ORNL DAAC.

Luthcke reported on GEDI’s current observed and estimated geolocation performance, including detailed summaries of component analysis and steps towards improving Precision Orbit Determination (POD), Precision Attitude Determination (PAD), Pointing Calibration, time-tag correction, and Oven Controlled Crystal Oscillator (OCXO) calibration. GEDI passes over Salar de Uyuni, the world’s largest salt flat located in Bolivia – see Figure 3, are being used to assess the PAD high-frequency and low-frequency errors. Estimated errors are shown to be consistent with observed geolocation errors. Finally, Luthcke gave a summary of completed L3 products and new wall-to-wall 1-km (0.62-mi) resolution and high-resolution products.

GEDI figure 3
Figure 3. Salar de Uyuni, the world’s largest salt flat as seen from the International Space Station.
Figure credit: Samantha Cristoforetti/ESA/NASA

John Armston [UMD—GEDI Co-I] updated attendees on GEDI L2 products. L2A consists of elevation and height metrics, and L2B consists of canopy cover and vertical profile metrics. To assess GEDI ground and canopy top measurement accuracy and improve algorithm performance, the mission team is using data collected from NASA Land, Vegetation, and Ice Sensor (LVIS) campaigns from 2016 to present. Armston reported that L2B estimates of canopy and ground reflectance were completed for the first mission epoch (April 2019–March 2023) and the GEDI team continues to work on algorithm improvements for cover estimates in challenging conditions (e.g., steep slopes). Data users can expect improved waveform processing for ground elevation and canopy height, new reflectance estimation, and revised quality metrics and flags in the L2A and L2B not-yet-released V3 products.

Jim Kellner [Brown University—GEDI Co-I] shared the current status of and planned algorithm improvements to the L4A data product, or the footprint-level aboveground biomass density product. The algorithm theoretical basis document for L4A data products was published in November 2022; it describes how models were developed and the importance of quality filtering. L4A data product development continues in tandem with updates to L2A data and improvements to existing calibration and validation data and ingestion of new data.

Sean Healey [U.S. Forest Service—GEDI Co-I] reviewed coverage and uncertainties of the recently produced V2 L4B data products – see Figure 4. Ongoing GEDI-relevant research includes:

  • investigating a statistical method called bootstrapping, which may allow more complex types of models;
  • conducting theoretical statistical studies aimed at decomposing mean square error for model-based methods; and
  • developing ways to estimate biomass change over time – which will become more important as the extended mission potentially stretches to a decade.
GEDI figure 4
Figure 4. Gridded mean aboveground biomass density [top] and standard error of the mean [bottom] from Version 2.1 of the GEDI L4B Gridded Aboveground Biomass Density product, published on October 29, 2023.
Figure credit: ORNL DAAC

Competed Science Team Presentations—Session 1

This GEDI STM was the last convergence of the first iteration of the GEDI competed ST. Attendees received final in-person updates on the cohort’s projects and plans for future research. Over the course of the three-day meeting, there were several sections dedicated to Competed ST Presentations. For purposes of organization in this report, each section has been given a session number. 

Taejin Park [NASA’s Ames Research Center (ARC) and Bay Area Environmental Research Institute (BAERI)] kicked off the ST presentations with an overview of his group’s progress in enhancing the predictions of forest height and aboveground biomass by incorporating GEDI L2, L3, and L4 data products into a process-based model, called Allometric Scaling Resource Limitation (ASRL), over the contiguous United States (CONUS). The ASRL model effectively captures large-scale, maximum tree size distribution and facilitates prognostic applications for predicting future aboveground biomass changes under various climate scenarios. Park also described collaborative research efforts with international partners  to map changes in aboveground biomass in tropical and temperate forests using a carbon management systems (CMS).

Kerri Vierling [University of Idaho] shared the results from her team’s projects demonstrating the use of GEDI data fusion products to describe patterns of bird and mammal distributions in western U.S. forests. The focal species for these projects include a suite of vertebrate forest carnivores, prey, and ecosystem engineer species that modify their environments in ways that create habitat for other creatures, e.g., woodpeckers – see Figure 5. Many of these species are of interest for management by a variety of state and federal agencies. Vierling also discussed ongoing analyses identifying biodiversity hotspots and land ownership patterns.

GEDI figure 5
Figure 5. A Female downy woodpecker creates a tree cavity that other organisms may use in the future for habitat. Woodpecker species are great examples of ecosystem engineers.
Figure credit: Doug Swartz/Macaulay Library at the Cornell Lab or Ornithology (ML 58304661)

Sean Healey presented on his competed ST research on Online Biomass Inference using Waveforms and iNventory (OBI-WAN), a Google Earth Engine application. This forest-carbon reporting tool harnesses GEDI waveforms, biomass models, and statistics to make estimates of mean biomass and biomass change for areas specified by online users. Healey explained the statistical methods applied to operate OBI-WAN and gave context for the use of sensor fusion to provide biomass change information that is critical for monitoring, reporting, and verification.

Keith Krause [Battelle] presented his work evaluating vertical structural similarity of LVIS classic and GEDI large-footprint waveforms. At the GEDI and LVIS footprint scale (20–23 m, or 65–75 ft, spot on the ground), lidar waveforms over forests represent canopies of leaves and branches from several trees. Krause presented results comparing waveforms against each other to show similarities in shape (i.e., if the trees in their footprints have a similar vertical structure). He also described how he used data clustering techniques to group similar waveforms into distinct structural classes. From there, he could map waveforms with similar vertical structure to better understand the spatial distribution of the structural groups.

Breakout Sessions—Session 1

GEDI STMs offer a rare opportunity for members of the competed and mission STs, a variety of stakeholders, and other individuals to convene and discuss ideas and goals for their own research and for the GEDI mission. Toward that end, breakout sessions were held on the first and second day of the meeting – referred to as Session 1 and Session 2 in this report. The individual breakout meetings used a hybrid format allowing in-person and online participants to join the discussion that was most relevant to their interests and expertise.

Chris Hakkenberg [Northern Arizona University (NAU)] led a breakout session on structural diversity, including the horizontal and vertical components. Different structural attributes, (e.g., stand structure, height, cover, and vegetation density) have different – but related – metrics and measurement approaches. Participants discussed biodiversity-structure relationships (BSRs), how to better characterize horizontal structural diversity, and how to define which metrics (i.e., scale, sampling unit, and spatial resolution) are most meaningful in different situations.

Jim Kellner led a session that focused on biomass calibration and validation and how to create the best data products given global environmental variation. Special cases – e.g., mangroves – pose challenges for calibration and validation because they don’t always have as much plot-level data as other environments. Participants discussed how to determine strata while considering climactic and environmental covariates as well as constraints of data availability and consistency.

Competed Science Team Presentations—Session 2

The FORest Carbon Estimation (FORCE) Project is exploring the use of GEDI-derived canopy structure metrics to map forest biomass in the U.S. and Canada. Daniel Hayes [University of Maine] presented comparisons of GEDI metrics and canopy height models derived from airborne lidar and photo point clouds over different forest types and disturbance history in managed forests of Maine. Co-PI Andy Finley [Michigan State University] presented new work that adjusts GEDI L4B biomass estimates to plot data over the continental U.S. from Forest Inventory and Analysis (FIA) program of the U.S. Department of Agriculture’s Forest Research and Development Branch. The project’s next steps are to fuse GEDI canopy structure metrics with other covariates in a spatial model to produce wall-to-wall estimates of biomass for boreal–temperate transition forests in northeast North America.

GEDI data is also being used to study tropical forests. Chris Doughty [NAU] described how he and his team analyzed GEDI L2A data across all tropical forests and found that tropical forest structure was less stratified and more exposed to sunlight than previously thought. Most tropical forests (80% of the Amazon and 70% of southeast Asia and the Congo Basin) have a peak in the number of leaves at 15 m (49 ft) instead of at the canopy top. Doughty and his team have found that deviation from more ideal conditions (i.e., lower fertility or higher temperatures) lead to shorter, less-stratified tropical forests with lower biomass.

Paul Moorcroft [Harvard University] reported on studies of current and future carbon dynamics across the Pacific Coast region based on forest structure and rates of carbon uptake. Moorcroft’s group examined how these ecosystems will behave in the future under different climate scenarios and have plans to conduct similar studies in other regions.

DAY TWO

Naikoa Aguilar-Amuchastegui [World Bank] kicked off day two with his perspective on the importance of streamlining the monitoring, reporting, and validation (MRV) process from scientific estimation to actual use of the data. Once scientific data is generated, end users are often faced with challenges related to transparency and understandability. Scientists can better communicate how to use their datasets properly, by familiarizing themselves with who wants to use their data, why they want to use it, and what their needs are. With this information in mind, data can be presented in more practical ways that allow for a variety of institutions with different standards and frameworks to integrate GEDI data more easily into their reporting. As the GEDI team continues to produce high-quality maps, efforts are underway to connect with end users and provide tutorials, workshops, and other resources.

GEDI Demonstrative Products

Demonstrative products show how GEDI data can be used in practice and in combination with other resources. Ecosystem modeling is one way that GEDI data are being used to address questions about aboveground carbon balance, future atmospheric CO2 concentrations, and habitat quality and biodiversity. George Hurtt [UMD—GEDI Co-I] shared his progress on integrating GEDI canopy height measurements with the Ecosystem Demography model to estimate current global forest carbon stocks and project future sequestration gaps under climate change – see Figure 6. Hurtt emphasized that this unprecedented volume of lidar data significantly enhances the ability of carbon models to capture spatial heterogeneity of forest carbon dynamics at 1 km (0.6 mi) scale, which is crucial for local policymaking regarding climate mitigation.

GEDI figure 6
Figure 6. [Top] Average lidar canopy height at 0.01° resolution, computed by gridding both GEDI and ICESat-2 together, and carbon stocks [middle] and fluxes [bottom] from ED-Lidar (GEDI and ICESat-2 combined). The insets highlight fine-scale spatial distribution and coverage gaps at selected regions (1.5° × 1.5°). Note that the three maps show grid-cell averages aggregated from sub-grid scale heterogeneity for each variable.
Figure credit: From a 2023 article in Global Change Biology.

There is also great potential for the development and application of methods for mapping forest structure, carbon stocks, and their changes by fusing data from GEDI and the Deutsches Zentrum für Luft- und Raumfahrt’s (DLR) [German Space Operations Center] TerraSAR-X Add-oN for Digital Elevation Measurement (TanDEM-X) satellite mission, which uses synthetic aperture radar (SAR) to gather three-dimensional (3D) images of Earth’s surface. This fusion product is being spearheaded by Wenlu Qi [UMD], who presented on efforts to create maps of pantropical canopy height, biomass, forest structure, and biomass change using the fusion product as well as maps of forests in temperate U.S. and Hawaii.

Data from the GEDI mission are also being used to quantify the spatial and temporal distribution of habitat structure, which influences habitat quality and biodiversity. Scott Goetz [NAU—GEDI Deputy PI] presented on biodiversity-related activities, citing a 2023 paper in Nature that examined the effectiveness of protected areas (PAs) across southeast Asia using GEDI data to compare canopy structure within and outside of PAs – see Figure 7. He also presented an analysis of tree and plant diversity across U.S. National Ecological Observation Network (NEON) sites that showed similar capabilities of GEDI with airborne laser scanning (ALS) for tree diversity.

GEDI figure 7
Figure 7. [Top] Protected Areas (PAs) such as national parks can reduce habitat loss and degradation (from logging) and extractive behaviors such as hunting (shown in red circle), but this figure shows there are a wide range of real-world outcomes based on management effectiveness. [Middle] PAs are aimed at safeguarding multiple facets of biodiversity, including species richness (SR), functional richness (FR) and phylogenetic diversity (PD). PAs often focus on vertebrate conservation, owing to their threat levels and value to humans – including for tourism. This study focused on wildlife in southeast Asia, with mammals shown here representing a variation of feeding guilds and sizes. The same approach is repeated for birds. [Bottom] Wildlife communities inside PAs and in the surrounding landscape may exhibit distinct levels and types of diversity.
Figure credit: From a 2023 article in Nature.

Competed Science Team Presentations—Session 3

One unique application of GEDI data is using lidar height to improve radiative transfer models for snow processes. Steven Hancock [University of Edinburgh, Scotland] reported on his group’s work studying snow, forest structure, and heterogeneity in forests, explaining that the majority of land surface models used for climate and weather forecasting use one-dimensional (1D) radiative transfer (RT) models driven by leaf area alone. Heterogeneous forests cast shadows and cause the surface albedo to depend upon sun angle and tree height for moderate leaf area indices (LAI), i.e., LAI values from  1-3 – which are common in snow-affected areas. This complexity cannot be represented in 1D models. An RT model can represent the effect of tree height and horizontal heterogeneity to simulate the observed change in albedo with height, which itself spatially varies.

In contrast to a snowy study area, Ovidiu Csillik [NASA/Jet Propulsion Laboratory] and his team are developing statistical models to link GEDI relative height metrics to tropical forest characteristics traceable to inventory measurements. This dataset of forest structure variables over the Amazon will be used to initialize a demographic ecosystem model to produce projections of future potential tropical forest carbon, as demonstrated by Amazon-wide simulations using initializations from airborne lidar sampling.

Wenge Ni-Meister [Hunter College of the City University of New York] is working on improving aboveground biomass estimates using GEDI waveform measurements. Ni-Meister and her team are testing models in both domestic and international tropical and temperate forests.

Breakout Sessions—Session 2

Two more breakout sessions occurred on day two:  

Sean Healey led a discussion on modes of inference for GEDI data. Inference – formally derived uncertainty for area estimates of biomass, height, or other metrics – can take different forms, each of which includes specific assumptions. In this breakout session, participants considered the strengths and limitations of different inference types (e.g., intensity of computation or the ability to use different models).

Laura Duncanson [UMD—GEDI Co-I] led a discussion about facilitation of open science, in other words, how to make GEDI data more accessible and digestible for data users. While GEDI data area free and publicly available via the LP DAAC and ORNL DAAC, gaining access to said data can be intimidating. Sharing more about existing resources and creating new ones can help remove barriers. The LP DAAC and ORNL DAAC have excellent tutorials on GitHub (a cloud-based software development platform that is primarily Python-based), and Google Earth Engine applications are available for accessing and visualizing GEDI data. Future endeavors may include more webinars, R-based tutorials, workshops, and trainings on specific topics and ways to use GEDI data. More information is available via an online compilation of GEDI-related tutorials.

Perspective: A NUVIEW of Earth’s Land Surface

For the second perspective presentation of day two, meeting attendees heard from Clint Graumann, CEO and co-founder of NUVIEW, a company whose mission is to build a commercial satellite constellation of lidar-imaging satellites that will produce 3D maps of the Earth’s entire land surface. Graumann shared NUVIEW’s intent to produce land surface maps on an annual basis and provide a variety of products and services, including digital surface models (DSMs), digital terrain models (DTMs), and a point cloud generated by laser pulses.

Competed Science Team Presentations—Session 4

Laura Duncanson began the second round of science presentations with her group’s research on global forest carbon hotspots. She discussed her 2023 paper in Nature Communications on the effectiveness of global PAs for climate change mitigation – see Figure 8, which found that the creation of PAs led to more biomass – especially in the Amazon. Within GEDI-domain terrestrial PAs, total aboveground biomass (AGB) storage was found to be 125 Pg, which is around 26% of global estimated AGB. Without the existence of PAs, 19.7 Gt of the 125 Pg would have likely been lost.

GEDI figure 8
Figure 8. PAs effectively preserve additional aboveground carbon (AGC) across continents and biomes, with forest biomes dominating the global signal, particularly in South America. The additional preserved AGC (Gt) in WWF biome classes (total Gt + /− SEM*area). World base map made with Natural Earth. The full set of analyzed GEDI data are represented in this figure (n = 412,100,767).
Figure credit: From a 2023 article in Nature Communications.

Another unique application of GEDI data has to do with water on the Earth’s surface. Kyungtae Lee [UMD], who works with Michelle Hofton [UMD—GEDI Co-I], reported that GEDI appears to capture the monthly annual cycle of lake elevation, showing good correlation with the ground-based observations. Lee explained that even though the GEDI lake elevation estimates show systematic biases relative to the local gauges, GEDI captures lake elevation dynamics well – especially the annual cycle variations. This work has the potential to expand knowledge of hydrological significance of lakes, particularly in data-limited areas of the world. Stephen Good [Oregon State University] presented a survey of his team’s recent work integrating observations from GEDI into hydrology and hydraulics studies of how vegetation can block and intercept moving water. The team found important nonlinear relationships between inferred canopy storage and canopy biomass and were able to estimate canopy water storage capacities and map these globally.

Finally, Patrick Burns [NAU], who works with Scott Goetz, presented results using GEDI canopy structure metrics in mammal species distribution models across southeast Asia (specifically focusing on Borneo and Sumatra). The team’s early results indicate that GEDI canopy structure metrics are important in many mammal distribution models and improve model performance for another smaller subset of species. In other words, when looking at predictors like mean annual precipitation or forest structure (forest structure being a metric that GEDI data provide), the GEDI-derived structure metrics are more intuitive and help us understand distributional changes and fine-scale habitat suitability. In a region like southeast Asia, for example, which has undergone high rates of deforestation in the recent decades, forest structure may be a more relevant predictor in a species distribution model (SDM) than other metrics like climate or vegetation composition. The team will continue to produce models for additional species and expand the extent of the analysis to include mainland Asia.

DAY THREE

Competed Science Team Presentations—Session 5

Day three began with the meeting’s last round of competed ST presentations. John Armston presented the progress of GEDI L2B Plant Area Volume Density (PAVD) product validation using a global Terrestrial Laser Scanning (TLS) database and fusion of the L2B product with Landsat time-series for quantifying change in canopy structure from the Australian wildfires of 2019–2020. Participants then heard from Jim Kellner on using machine-learning algorithms for L4A aboveground biomass density (AGBD). The performance of machine-learning algorithms on a testing data set was comparable to linear regressions used for the first releases of GEDI AGBD data products on average – although there were important geographical differences associated with machine learning. One application under investigation is using machine learning to identify new potential stratifications for GEDI footprint aboveground biomass density.

Lastly, Jingyu Dai [New Mexico State University (NMSU)], who works with Niall Hanan [NMSU], presented on her analysis of the global limits to tree height. Her study shows that hydraulic limitation is the most important constraint on maximum canopy height globally. This result is mediated by plant functional type. In addition, rougher terrain promotes forest height at sub-landscape scales by enriching local niche diversity and probability of larger trees.

Perspective from the Data Side

As described in the summary of Ralph Dubayah’s introductory remarks, the LP DAAC and ORNL DAAC play essential roles in the dissemination of GEDI data and the success of the GEDI program. Representatives from each of these DAACs addressed the ST to summarize recent GEDI-related activities.

Aaron Friesz [United States Geological Survey (USGS)] represented the LP DAAC and gave an update on the current archive size, distribution metrics, and outreach activities. He also discussed plans to support the growth and sustainability of the community through collaboration activities that will leverage the GitHub application; he described some of the resources that are available. Friesz then highlighted the USGS Eyes on Earth podcast and the Institute of Electrical and Electronics Engineers (IEEE) Geoscience and Remote Sensing Society (GRSS)’s Down to Earth podcast, which have featured Ralph Dubayah and Laura Duncanson, and shared plans to update the current GitHub tutorials and how-to guides in the Earthdata Cloud of GEDI V2 and V3.

Rupesh Shrestha [ORNL] represented the ORNL DAAC and shared the status of GEDI L3, L4A, and L4B datasets archived there. He gave an overview of data tools and services for the GEDI datasets, which can be found on the GEDI website and GitHub tutorials website. GEDI L3, L4A, and L4B are available on NASA’s Earthdata Cloud and various enterprise-level services, such as NASA’s WorldView, Harmony, and OpenDAP. GEDI data usage metrics, data tutorials and workshops, and outreach activities, as well as other published community and related datasets were also highlighted. GEDI L3, L4A, and L4B have been downloaded over four million times collectively.

Neha Hunka [UMD] gave the final presentation of the meeting on biomass harmonization activities. She reported that the GEDI estimates of aboveground biomass are capable of directly contributing to the United Nations Framework Convention on Climate Change Global Stocktake. Hunka and her colleagues’ research is aimed at bridging the science–policy gap to enable the use of space-based aboveground biomass estimates for policy reporting and impact – see Figure 9.

GEDI figure 9
Figure 9. Forest biomass estimates in the format of Intergovernmental Panel on Climate Change (IPCC) Tier 1 values from NASA GEDI and ESA Climate Change Initiative (CCI) maps.
Figure credit: Neha Hunka

Conclusion

Overall, the 2023 GEDI STM showcased an exceptional array of scientific research that is highly relevant to addressing pressing global challenges and answering key questions about global forest structure, carbon balance, habitat quality, and biodiversity among other topics. As the GEDI instrument enters its second epoch, we are excited to welcome a new competed GEDI science team cohort and look forward to the release of V3 data products later this year.

Ralph Dubayah concluded the STM with a summary of hibernation period goals and a farewell to this iteration of the competed ST. He extended a heartfelt thank you and farewell to Hank Margolis [NASA Headquarters, emeritus] who has been the NASA Program Scientist for the GEDI mission since 2015. Thank you, Hank. We will miss you.

Talia Schwelling
University of Maryland, College Park
tschwell@umd.edu

View the full article

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
 Share
Go to topic listing

  • Similar Topics

    • NASA
      Ames Science Directorate’s Stars of the Month: July 2025
      By NASA
      The NASA Ames Science Directorate recognizes the outstanding contributions of (pictured left to right) Sigrid Reinsch, Lori Munar, Kevin Sims, and Matthew Fladeland. Their commitment to the NASA mission represents the entrepreneurial spirit, technical expertise, and collaborative disposition needed to explore this world and beyond.
      Space Biosciences Star: Sigrid Reinsch
      As Director of the SHINE (Space Health Impacts for the NASA Experience) program and Project Scientist for NBISC (NASA Biological Institutional Scientific Collection), Sigrid Reinsch is a high-performing scientist and outstanding mentor in the Space Biosciences Research Branch. Her dedication to student training and her efforts to streamline processes have significantly improved the experience of welcoming summer interns at NASA Ames.

      Space Science and Astrobiology Star: Lori Munar
      Lori Munar serves as the assistant Branch Chief of the Exobiology Branch. In the past few months, she has gone above and beyond to organize a facility and laboratory surplus event that involved multiple divisions over multiple days. The event resulted in considerable savings across the groups involved and improved the safety of N239 staff and the appearance of offices and labs.
      Space Science and Astrobiology Star: Kevin Sims
      Kevin Sims is a NASA Technical Project Manager serving the Astrophysics Branch as a member of the Flight Systems Implementation Branch in the Space Biosciences Division. Kevin is recognized for outstanding project management for exoplanet imaging instrumentation development in support of the Habitable Worlds Observatory. Kevin has streamlined, organized, and improved the efficiency of the Ames Photonics Testbed being developed as part the AstroPIC Early Career Initiative project.
      Earth Science Star: Matthew Fladeland
      Matthew Fladeland is a research scientist in the Earth Science Division managing NASA SMD’s Program Office for the Airborne Science Program, located at Ames. He is recognized for exemplary leadership and teamwork leading to new reimbursable agreements with the Department of Defense, for accelerating science technology solutions through the SBIR program, and for advancing partnerships with the US Forest Service on wildland ecology and fire science.
      View the full article
    • NASA
      Meet the Space Ops Team: Derrick Bailey
      By NASA
      3 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      Since childhood, Derrick Bailey always had an early fascination with aeronautics. Military fighter jet pilots were his childhood heroes, and he dreamed of joining the aerospace industry. This passion was a springboard into his 17-year career at NASA, where Bailey plays an important role in enabling successful rocket launches.

      Bailey is the Launch Vehicle Certification Manager in the Launch Services Program (LSP) within the Space Operations Mission Directorate. In this role, he helps NASA outline the agency’s risk classifications of new rockets from emerging and established space companies.

      “Within my role, I formulate a series of technical and process assessments for NASA LSP’s technical team to understand how companies operate, how vehicles are designed and qualified, and how they perform in flight,” Bailey said.

      Beyond technical proficiency and readiness, a successful rocket launch relies on establishing a strong foundational relationship between NASA and the commercial companies involved. Bailey and his team ensure effective communication with these companies to provide the guidance, data, and analysis necessary to support them in overcoming challenges.

      “We work diligently to build trusting relationships with commercial companies and demonstrate the value in partnering with our team,” Bailey said.

      Bailey credits a stroke of fate that landed him at the agency. During his senior year at Georgia Tech, where he was pursuing a degree in aerospace engineering, Bailey almost walked past the NASA tent at a career fair. However, he decided to grab a NASA sticker and strike up a conversation, which quickly turned into an impromptu interview. He walked away that day with a job offer to work on the now-retired Space Shuttle Program at the agency’s Kennedy Space Center in Florida.

      “I never imagined working at NASA,” Bailey said. “Looking back, it’s unbelievable that a chance encounter resulted in securing a job that has turned into an incredible career.”

      Thinking about the future, Bailey is excited about new opportunities in the commercial space industry. Bailey sees NASA as a crucial advisor and mentor for commercial sector while using industry capabilities to provide more cost-effective access to space.

      Derrick Bailey, launch vehicle certification manager for NASA’s Launch Services Program
      “We are the enablers,” Bailey said of his role in the directorate. “It is our responsibility to provide the best opportunity for future explorers to begin their journey of discovery in deep space and beyond.”

      Outside of work, Bailey enjoys spending time with his family, especially his two sons, who keep him busy with trips to the baseball diamond and homework sessions. Bailey also enjoys hands-on activities, like working on cars, off-road vehicles, and house projects – hobbies he picked up from his mechanically inclined father. Additionally, at the beginning of 2025, his wife accepted a program specialist position with LSP, an exciting development for the entire Bailey family.

      “One of my wife’s major observations early on in my career was how much my colleagues genuinely care about one another and empower people to make decisions,” Bailey explained. “These are the things that make NASA the number one place to work in the government.”
      NASA’s Space Operations Mission Directorate maintains a continuous human presence in space for the benefit of people on Earth. The programs within the directorate are the hub of NASA’s space exploration efforts, enabling Artemis, commercial space, science, and other agency missions through communication, launch services, research capabilities, and crew support.

      To learn more about NASA’s Space Operation Mission Directorate, visit: 
      https://www.nasa.gov/directorates/space-operations
      Share
      Details
      Last Updated Jun 26, 2025 Related Terms
      Space Operations Mission Directorate People of Space Operations Explore More
      4 min read NASA to Gather In-Flight Imagery of Commercial Test Capsule Re-Entry
      Article 1 week ago 4 min read Meet the Space Ops Team: Christine Braden
      Article 1 month ago 4 min read NASA Enables SPHEREx Data Return Through Commercial Partnership
      Article 2 months ago View the full article
    • NASA
      NASA, Australia Team Up for Artemis II Lunar Laser Communications Test
      By NASA
      An artist’s concept of NASA’s Orion spacecraft orbiting the Moon while using laser communications technology through the Orion Artemis II Optical Communications System.Credit: NASA/Dave Ryan As NASA prepares for its Artemis II mission, researchers at the agency’s Glenn Research Center in Cleveland are collaborating with The Australian National University (ANU) to prove inventive, cost-saving laser communications technologies in the lunar environment.
      Communicating in space usually relies on radio waves, but NASA is exploring laser, or optical, communications, which can send data 10 to 100 times faster to the ground. Instead of radio signals, these systems use infrared light to transmit high-definition video, picture, voice, and science data across vast distances in less time. NASA has proven laser communications during previous technology demonstrations, but Artemis II will be the first crewed mission to attempt using lasers to transmit data from deep space.
      To support this effort, researchers working on the agency’s Real Time Optical Receiver (RealTOR) project have developed a cost-effective laser transceiver using commercial-off-the-shelf parts. Earlier this year, NASA Glenn engineers built and tested a replica of the system at the center’s Aerospace Communications Facility, and they are now working with ANU to build a system with the same hardware models to prepare for the university’s Artemis II laser communications demo.
      “Australia’s upcoming lunar experiment could showcase the capability, affordability, and reproducibility of the deep space receiver engineered by Glenn,” said Jennifer Downey, co-principal investigator for the RealTOR project at NASA Glenn. “It’s an important step in proving the feasibility of using commercial parts to develop accessible technologies for sustainable exploration beyond Earth.”

      During Artemis II, which is scheduled for early 2026, NASA will fly an optical communications system aboard the Orion spacecraft, which will test using lasers to send data across the cosmos. During the mission, NASA will attempt to transmit recorded 4K ultra-high-definition video, flight procedures, pictures, science data, and voice communications from the Moon to Earth.
      An artist’s concept of the optical communications ground station at Mount Stromlo Observatory in Canberra, Australia, using laser communications technology.Credit: The Australian National University Nearly 10,000 miles from Cleveland, ANU researchers working at the Mount Stromlo Observatory ground station hope to receive data during Orion’s journey around the Moon using the Glenn-developed transceiver model. This ground station will serve as a test location for the new transceiver design and will not be one of the mission’s primary ground stations. If the test is successful, it will prove that commercial parts can be used to build affordable, scalable space communication systems for future missions to the Moon, Mars, and beyond.
      “Engaging with The Australian National University to expand commercial laser communications offerings across the world will further demonstrate how this advanced satellite communications capability is ready to support the agency’s networks and missions as we set our sights on deep space exploration,” said Marie Piasecki, technology portfolio manager for NASA’s Space Communications and Navigation (SCaN) Program.
      As NASA continues to investigate the feasibility of using commercial parts to engineer ground stations, Glenn researchers will continue to provide critical support in preparation for Australia’s demonstration.

      Strong global partnerships advance technology breakthroughs and are instrumental as NASA expands humanity’s reach from the Moon to Mars, while fueling innovations that improve life on Earth. Through Artemis, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and build the foundation for the first crewed missions to Mars.
      The Real Time Optical Receiver (RealTOR) team poses for a group photo in the Aerospace Communications Facility at NASA’s Glenn Research Center in Cleveland on Friday, Dec. 13, 2024. From left to right: Peter Simon, Sarah Tedder, John Clapham, Elisa Jager, Yousef Chahine, Michael Marsden, Brian Vyhnalek, and Nathan Wilson.Credit: NASA The RealTOR project is one aspect of the optical communications portfolio within NASA’s SCaN Program, which includes demonstrations and in-space experiment platforms to test the viability of infrared light for sending data to and from space. These include the LCOT (Low-Cost Optical Terminal) project, the Laser Communications Relay Demonstration, and more. NASA Glenn manages the project under the direction of agency’s SCaN Program at NASA Headquarters in Washington.
      The Australian National University’s demonstration is supported by the Australian Space Agency Moon to Mars Demonstrator Mission Grant program, which has facilitated operational capability for the Australian Deep Space Optical Ground Station Network.
      To learn how space communications and navigation capabilities support every agency mission, visit:
      https://www.nasa.gov/communicating-with-missions


      Explore More
      3 min read NASA Engineers Simulate Lunar Lighting for Artemis III Moon Landing
      Article 1 week ago 2 min read NASA Seeks Commercial Feedback on Space Communication Solutions
      Article 1 week ago 4 min read NASA, DoD Practice Abort Scenarios Ahead of Artemis II Moon Mission
      Article 2 weeks ago View the full article
    • NASA
      NASA’s Perseverance Rover Scours Mars for Science
      By NASA
      6 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      In addition to drilling rock core samples, the science team has been grinding its way into rocks to make sense of the scientific evidence hiding just below the surface.
      NASA’s Perseverance rover uses an abrading bit to get below the surface of a rocky out-crop nicknamed “Kenmore” on June 10. The eight images that make up this video were taken approximately one minute apart by one of the rover’s front hazard-avoidance cameras. NASA/JPL-Caltech On June 3, NASA’s Perseverance Mars rover ground down a portion of a rock surface, blew away the resulting debris, and then went to work studying its pristine interior with a suite of instruments designed to determine its mineralogic makeup and geologic origin. “Kenmore,” as nicknamed by the rover science team, is the 30th Martian rock that Perseverance has subjected to such in-depth scrutiny, beginning with drilling a two-inch-wide (5-centimeter-wide) abrasion patch.  
      “Kenmore was a weird, uncooperative rock,” said Perseverance’s deputy project scientist, Ken Farley from Caltech in Pasadena, California. “Visually, it looked fine — the sort of rock we could get a good abrasion on and perhaps, if the science was right, perform a sample collection. But during abrasion, it vibrated all over the place and small chunks broke off. Fortunately, we managed to get just far enough below the surface to move forward with an analysis.”
      The science team wants to get below the weathered, dusty surface of Mars rocks to see important details about a rock’s composition and history. Grinding away an abrasion patch also creates a flat surface that enables Perseverance’s science instruments to get up close and personal with the rock.
      This close-up view of an abrasion showing distinctive “tool marks” created by the Perseverance’s abrading bit was acquired on June 5. The image was taken from approximately 2.76 inches (7 centimeters) away by the rover’s WATSON imager. NASA/JPL-Caltech/MSSS Perseverance’s gold-colored abrading bit takes center stage in this image of the rover’s drill taken by the Mastcam-Z instrument on Aug. 2, 2021, the 160th day of the mission to Mars.NASA/JPL-Caltech/ASU/MSSS Time to Grind
      NASA’s Mars Exploration Rovers, Spirit and Opportunity, each carried a diamond-dust-tipped grinder called the Rock Abrasion Tool (RAT) that spun at 3,000 revolutions per minute as the rover’s robotic arm pushed it deeper into the rock. Two wire brushes then swept the resulting debris, or tailings, out of the way. The agency’s Curiosity rover carries a Dust Removal Tool, whose wire bristles sweep dust from the rock’s surface before the rover drills into the rock. Perseverance, meanwhile, relies on a purpose-built abrading bit, and it clears the tailings with a device that surpasses wire brushes: the gaseous Dust Removal Tool, or gDRT.
      “We use Perseverance’s gDRT to fire a 12-pounds-per-square-inch (about 83 kilopascals) puff of nitrogen at the tailings and dust that cover a freshly abraded rock,” said Kyle Kaplan, a robotic engineer at NASA’s Jet Propulsion Laboratory in Southern California. “Five puffs per abrasion — one to vent the tanks and four to clear the abrasion. And gDRT has a long way to go. Since landing at Jezero Crater over four years ago, we’ve puffed 169 times. There are roughly 800 puffs remaining in the tank.” The gDRT offers a key advantage over a brushing approach: It avoids any terrestrial contaminants that might be on a brush from getting on the Martian rock being studied.
      To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video
      This video captures a test of Perseverance’s Gaseous Dust Removal Tool (gDRT) in a vacuum chamber at NASA’s Jet Propulsion Laboratory in August 2020. The tool fires puffs of nitrogen gas at the tailings and dust that cover a rock after it has been abraded by the rover.NASA/JPL-Caltech Having collected data on abraded surfaces more than 30 times, the rover team has in-situ science (studying something in its original place or position) collection pretty much down. After gDRT blows the tailings away, the rover’s WATSON (Wide Angle Topographic Sensor for Operations and eNgineering) imager (which, like gDRT, is at the end of the rover’s arm) swoops in for close-up photos. Then, from its vantage point high on the rover’s mast, SuperCam fires thousands of individual pulses from its laser, each time using a spectrometer to determine the makeup of the plume of microscopic material liberated after every zap. SuperCam also employs a different spectrometer to analyze the visible and infrared light that bounces off the materials in the abraded area.
      “SuperCam made observations in the abrasion patch and of the powdered tailings next to the patch,” said SuperCam team member and “Crater Rim” campaign science lead, Cathy Quantin-Nataf of the University of Lyon in France. “The tailings showed us that this rock contains clay minerals, which contain water as hydroxide molecules bound with iron and magnesium — relatively typical of ancient Mars clay minerals. The abrasion spectra gave us the chemical composition of the rock, showing enhancements in iron and magnesium.”
      Later, the SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) and PIXL (Planetary Instrument for X-ray Lithochemistry) instruments took a crack at Kenmore, too. Along with supporting SuperCam’s discoveries that the rock contained clay, they detected feldspar (the mineral that makes much of the Moon brilliantly bright in sunlight). The PIXL instrument also detected a manganese hydroxide mineral in the abrasion — the first time this type of material has been identified during the mission.  
      With Kenmore data collection complete, the rover headed off to new territories to explore rocks — both cooperative and uncooperative — along the rim of Jezero Crater.
      “One thing you learn early working on Mars rover missions is that not all Mars rocks are created equal,” said Farley. “The data we obtain now from rocks like Kenmore will help future missions so they don’t have to think about weird, uncooperative rocks. Instead, they’ll have a much better idea whether you can easily drive over it, sample it, separate the hydrogen and oxygen contained inside for fuel, or if it would be suitable to use as construction material for a habitat.”
      Long-Haul Roving
      On June 19 (the 1,540th Martian day, or sol, of the mission), Perseverance bested its previous record for distance traveled in a single autonomous drive, trekking 1,348 feet (411 meters). That’s about 210 feet (64 meters) more than its previous record, set on April 3, 2023 (Sol 753). While planners map out the rover’s general routes, Perseverance can cut down driving time between areas of scientific interest by using its self-driving system, AutoNav.
      “Perseverance drove 4½ football fields and could have gone even farther, but that was where the science team wanted us to stop,” said Camden Miller, a rover driver for Perseverance at JPL. “And we absolutely nailed our stop target location. Every day operating on Mars, we learn more on how to get the most out of our rover. And what we learn today future Mars missions won’t have to learn tomorrow.”
      News Media Contact
      DC Agle
      Jet Propulsion Laboratory, Pasadena, Calif.
      818-393-9011
      agle@jpl.nasa.gov
      Karen Fox / Molly Wasser
      NASA Headquarters, Washington
      202-358-1600
      karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov    
      2025-082
      Share
      Details
      Last Updated Jun 25, 2025 Related Terms
      Perseverance (Rover) Jet Propulsion Laboratory Mars Explore More
      5 min read NASA’s Curiosity Mars Rover Starts Unpacking Boxwork Formations
      Article 2 days ago 4 min read NASA Mars Orbiter Captures Volcano Peeking Above Morning Cloud Tops
      Article 3 weeks ago 6 min read NASA’s Ready-to-Use Dataset Details Land Motion Across North America
      Article 3 weeks ago Keep Exploring Discover Related Topics
      Missions
      Humans in Space
      Climate Change
      Solar System
      View the full article
    • NASA
      NASA Glenn Joins COSI’s Big Science Celebration
      By NASA
      At COSI’s Big Science Celebration on Sunday, May 4, 2025, a young visitor uses one of NASA Glenn Research Center’s virtual reality headsets to immerse herself in a virtual environment. Credit: NASA/Lily Hammel  NASA’s Glenn Research Center joined the Center for Science and Industry (COSI) Big Science Celebration on the museum’s front lawn in Columbus, Ohio, on May 4. This event centered on science activities by STEM professionals, researchers, and experts from Central Ohio — and despite chilly, damp weather, it drew more than 20,000 visitors. 
      At COSI’s Big Science Celebration on Sunday, May 4, 2025, a young visitor steps out of the rain and into NASA Glenn Research Center’s booth to check out the Graphics and Visualization Lab’s augmented reality fluid flow table that allows users to virtually explore a model of the International Space Station. Credit: NASA/Lily Hammel  NASA’s 10-by-80-foot tent housed a variety of information booths and hands-on demonstrations to introduce guests to the vital research being performed at the Cleveland center. Popular attractions included a mini wind tunnel and multiple augmented and virtual reality demonstrations. Visitors also engaged through tangram puzzles and a cosmic selfie station. NASA Glenn’s astronaut mascot made several appearances to the delight of young and old alike.   
      Return to Newsletter View the full article

  • Check out these Videos

×
×
  • Create New...