Members Can Post Anonymously On This Site
-
Similar Topics
-
By NASA
8 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Return to 2024 SARP Closeout Faculty Advisors:
Dr. Tom Bell, Woods Hole Oceanographic Institution
Dr. Kelsey Bisson, NASA Headquarters Science Mission Directorate
Graduate Mentor:
Kelby Kramer, Massachusetts Institute of Technology
Kelby Kramer, Graduate Mentor
Kelby Kramer, graduate mentor for the 2024 SARP Ocean Remote Sensing group, provides an introduction for each of the group members and shares behind-the scenes moments from the internship.
Lucas DiSilvestro
Shallow Water Benthic Cover Type Classification using Hyperspectral Imagery in Kaneohe Bay, Oahu, Hawaii
Lucas DiSilvestro
Quantifying the changing structure and extent of benthic coral communities is essential for informing restoration efforts and identifying stressed regions of coral. Accurate classification of shallow-water benthic coral communities requires high spectral and spatial resolution, currently not available on spaceborne sensors, to observe the seafloor through an optically complex seawater column. Here we create a shallow water benthic cover type map of Kaneohe Bay, Oahu, Hawaii using the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) without requiring in-situ data as inputs. We first run the AVIRIS data through a semi-analytical inversion model to derive color dissolved organic matter, chlorophyll concentration, bottom albedo, suspended sediment, and depth parameters for each pixel, which are then matched to a Hydrolight simulated water column. Pure reflectance for coral, algae, and sand are then projected through each water column to create spectral endmembers for each pixel. Multiple Endmember Spectral Mixture Analysis (MESMA) provides fractional cover of each benthic class on a per-pixel basis. We demonstrate the efficacy of using simulated water columns to create surface reflectance spectral endmembers as Hydrolight-derived in-situ endmember spectra strongly match AVIRIS surface reflectance for corresponding locations (average R = 0.96). This study highlights the capabilities of using medium-fine resolution hyperspectral imagery to identify fractional cover type of localized coral communities and lays the groundwork for future spaceborne hyperspectral monitoring of global coral communities.
Atticus Cummings
Quantifying Uncertainty In Kelp Canopy Remote Sensing Using the Harmonized Landsat Sentinel-2 Dataset
Atticus Cummings
California’s giant kelp forests serve as a major foundation for the region’s rich marine biodiversity and provide recreational and economic value to the State of California. With the rising frequency of marine heatwaves and extreme weather onset by climate change, it has become increasingly important to study these vital ecosystems. Kelp forests are highly dynamic, changing across several timescales; seasonally due to nutrient concentrations, waves, and predator populations, weekly with typical growth and decay, and hourly with the tides and currents. Previous remote sensing of kelp canopies has relied on Landsat imagery taken with a eight-day interval, limiting the ability to quantify more rapid changes. This project aims to address uncertainty in kelp canopy detection using the Harmonized Landsat and Sentinel-2 (HLS) dataset’s zero to five-day revisit period. A random forest classifier was used to identify pixels that contain kelp, on which Multiple Endmember Spectral Mixture Analysis (MESMA) was then run to quantify intrapixel kelp density. Processed multispectral satellite images taken within 3 days of one another were paired for comparison. The relationship between fluctuations in kelp canopy density with tides and currents was assessed using in situ data from an acoustic doppler current profiler (ADCP) at the Santa Barbara Long Term Ecological Research site (LTER) and a NOAA tidal buoy. Preliminary results show that current and tidal trends cannot be accurately correlated with canopy detection due to other sources of error. We found that under cloud-free conditions, canopy detection between paired images varied on average by 42%. Standardized image processing suggests that this uncertainty is not created within the image processing step, but likely arises due to exterior factors such as sensor signal noise, atmospheric conditions, and sea state. Ultimately, these errors could lead to misinterpretation of remotely sensed kelp ecosystems, highlighting the need for further research to identify and account for uncertainties in remote sensing of kelp canopies.
Jasmine Sirvent
Kelp Us!: A Methods Analysis for Predicting Kelp Pigment Concentrations from Hyperspectral Reflectance
Jasmine Sirvent
Ocean color remote sensing enables researchers to assess the quantity and physiology of life in the ocean, which is imperative to understanding ecosystem health and formulating accurate predictions. However, without proper methods to analyze hyperspectral data, correlations between spectral reflectance and physiological traits cannot be accurately derived. In this study, I explored different methods—single variable regression, partial least squares regressions (PLSR), and derivatives—in analyzing in situ Macrocystis pyrifera (giant kelp) off the coast of Santa Barbara, California in order to predict pigment concentrations from AVIRIS hyperspectral reflectance. With derivatives as a spectral diagnostic tool, there is evidence suggesting high versus low pigment concentrations could be diagnosed; however, the fluctuations were within 10 nm of resolution, thus AVIRIS would be unable to reliably detect them. Exploring a different method, I plotted in situ pigment measurements — chlorophyll a, fucoxanthin, and the ratio of fucoxanthin to chlorophyll a—against hyperspectral reflectance that was resampled to AVIRIS bands. PLSR proved to be a more successful model because of its hyperdimensional analysis capabilities in accounting for multiple wavelength bands, reaching R2 values of 0.67. Using this information, I constructed a model that predicts kelp pigments from simulated AVIRIS reflectance using a spatial time series of laboratory spectral measurements and photosynthetic pigment concentrations. These results have implications, not only for kelp, but many other photosynthetic organisms detectable by hyperspectral airborne or satellite sensors. With these findings, airborne optical data could possibly predict a plethora of other biogeochemical traits. Potentially, this research would permit scientists to acquire data analogous to in situ measurements about floating matters that cannot financially and pragmatically be accessed by anything other than a remote sensor.
Isabelle Cobb
Correlations Between SSHa and Chl-a Concentrations in the Northern South China Sea
Isabelle Cobb
Sea surface height anomalies (SSHa)–variations in sea surface height from climatological averages–occur on seasonal timescales due to coastal upwelling and El Niño-Southern Oscillation (ENSO) cycles. These anomalies are heightened when upwelling plumes bring cold, nutrient-rich water to the surface, and are particularly strong along continental shelves in the Northern South China Sea (NSCS). This linkage between SSHa and nutrient availability has interesting implications for changing chlorophyll-a (chl-a) concentrations, a prominent indicator of phytoplankton biomass that is essential to the health of marine ecosystems. Here, we evaluate the long-term (15 years) relationship between SSHa and chl-a, in both satellite remote sensing data and in situ measurements. Level 3 SSHa data from Jason 1/2/3 satellites and chl-a data from MODIS Aqua were acquired and binned to monthly resolution. We found a significant inverse correlation between SSHa and chl-a during upwelling months in both the remote sensing (Spearman’s R=-0.57) and in situ data, with higher resolution in situ data from ORAS4 (an assimilation of buoy observations from 2003-2017) showing stronger correlations (Spearman’s R=-0.75). In addition, the data reveal that the magnitude of SSH increases with time during instances of high correlation, possibly indicating a trend of increased SSH associated with reduced seasonal chl-a concentrations. Thus, this relationship may inform future work predicting nutrient availability and threats to marine ecosystems as climate change continues to affect coastal sea surface heights.
Alyssa Tou
Exploring Coastal Sea Surface Temperature Anomalies and their effect on Coastal Fog through analyzing Plant Phenology
Alyssa Tou
Marine heat waves (MHW) have been increasing in frequency, duration and intensity, giving them substantial potential to influence ecosystems. Do these MHWs sufficiently enhance coastal precipitation such that plant growth is impacted? Recently, the Northeast Pacific experienced a long, intense MHW in 2014/2015, and another short, less intense MHW in 2019/2020. Here we investigate how the intensity and duration of MHWs influence the intensity and seasonal cycle of three different land cover types (‘grass’, ‘trees’, and a combination of both ‘combined’’) to analyze plant phenology trends in Big Sur, California. We hypothesize that longer intense MHWs decrease the ocean’s evaporative capacity, decreasing fog, thus lowering plant productivity, as measured by Normalized Difference Vegetation Index (NDVI). Sea surface temperature (SST) and NDVI data were collected from the NOAA Coral Reef Watch, and NASA MODIS/Terra Vegetation Indices 16-Day L3 Global 250m products respectively. Preliminary results show no correlation (R2=0.02) between SSTa and combined NDVI values and no correlation (R2=0.01) between SST and NDVI. This suggests that years with anomalously high SST do not significantly impact plant phenology. During the intense and long 2014/2015 MHW, peak NDVI values for ‘grass’ and ‘combined’ pixels were 2.0 and 1.7 standard deviations above the climatological average, while the shorter 2019/2020 MHW saw higher peaks of 3.2 and 2.4 standard deviations. However, the ‘grass’, ‘tree’ and ‘combined’ NDVI anomalies were statistically insignificant during both MHWs, showing that although NDVI appeared to increase during the shorter and less intense MHW, these values may be attributed to other factors. The data qualitatively suggest that MHW’s don’t impact the peak NDVI date, but more data at higher temporal resolution are necessary. Further research will involve analyzing fog indices and exploring confounding variables impacting NDVI, such as plant physiology, anthropogenic disturbance, and wildfires. In addition, it’s important to understand to what extent changes in NDVI are attributed to the driving factors of MHWs or the MHWs themselves. Ultimately, mechanistically understanding the impacts MHW intensity and duration have on terrestrial ecosystems will better inform coastal community resilience.
Return to 2024 SARP Closeout Share
Details
Last Updated Nov 22, 2024 Related Terms
General Explore More
10 min read SARP East 2024 Atmospheric Science Group
Article 21 mins ago 10 min read SARP East 2024 Hydroecology Group
Article 21 mins ago 11 min read SARP East 2024 Terrestrial Fluxes Group
Article 22 mins ago View the full article
-
By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
A prototype of a robot designed to explore subsurface oceans of icy moons is reflected in the water’s surface during a pool test at Caltech in September. Conducted by NASA’s Jet Propulsion Laboratory, the testing showed the feasibility of a mission concept for a swarm of mini swimming robots.NASA/JPL-Caltech In a competition swimming pool, engineers tested prototypes for a futuristic mission concept: a swarm of underwater robots that could look for signs of life on ocean worlds.
When NASA’s Europa Clipper reaches its destination in 2030, the spacecraft will prepare to aim an array of powerful science instruments toward Jupiter’s moon Europa during 49 flybys, looking for signs that the ocean beneath the moon’s icy crust could sustain life. While the spacecraft, which launched Oct. 14, carries the most advanced science hardware NASA has ever sent to the outer solar system, teams are already developing the next generation of robotic concepts that could potentially plunge into the watery depths of Europa and other ocean worlds, taking the science even further.
This is where an ocean-exploration mission concept called SWIM comes in. Short for Sensing With Independent Micro-swimmers, the project envisions a swarm of dozens of self-propelled, cellphone-size swimming robots that, once delivered to a subsurface ocean by an ice-melting cryobot, would zoom off, looking for chemical and temperature signals that could indicate life.
Dive into underwater robotics testing with NASA’s futuristic SWIM (Sensing With Independent Micro-swimmers) concept for a swarm of miniature robots to explore subsurface oceans on icy worlds, and see a JPL team testing a prototype at a pool at Caltech in Pasadena, California, in September 2024. NASA/JPL-Caltech “People might ask, why is NASA developing an underwater robot for space exploration? It’s because there are places we want to go in the solar system to look for life, and we think life needs water. So we need robots that can explore those environments — autonomously, hundreds of millions of miles from home,” said Ethan Schaler, principal investigator for SWIM at NASA’s Jet Propulsion Laboratory in Southern California.
Under development at JPL, a series of prototypes for the SWIM concept recently braved the waters of a 25-yard (23-meter) competition swimming pool at Caltech in Pasadena for testing. The results were encouraging.
SWIM Practice
The SWIM team’s latest iteration is a 3D-printed plastic prototype that relies on low-cost, commercially made motors and electronics. Pushed along by two propellers, with four flaps for steering, the prototype demonstrated controlled maneuvering, the ability to stay on and correct its course, and a back-and-forth “lawnmower” exploration pattern. It managed all of this autonomously, without the team’s direct intervention. The robot even spelled out “J-P-L.”
Just in case the robot needed rescuing, it was attached to a fishing line, and an engineer toting a fishing rod trotted alongside the pool during each test. Nearby, a colleague reviewed the robot’s actions and sensor data on a laptop. The team completed more than 20 rounds of testing various prototypes at the pool and in a pair of tanks at JPL.
“It’s awesome to build a robot from scratch and see it successfully operate in a relevant environment,” Schaler said. “Underwater robots in general are very hard, and this is just the first in a series of designs we’d have to work through to prepare for a trip to an ocean world. But it’s proof that we can build these robots with the necessary capabilities and begin to understand what challenges they would face on a subsurface mission.”
Swarm Science
A model of the final envisioned SWIM robot, right, sits beside a capsule holding an ocean-composition sensor. The sensor was tested on an Alaskan glacier in July 2023 through a JPL-led project called ORCAA (Ocean Worlds Reconnaissance and Characterization of Astrobiological Analogs). The wedge-shaped prototype used in most of the pool tests was about 16.5 inches (42 centimeters) long, weighing 5 pounds (2.3 kilograms). As conceived for spaceflight, the robots would have dimensions about three times smaller — tiny compared to existing remotely operated and autonomous underwater scientific vehicles. The palm-size swimmers would feature miniaturized, purpose-built parts and employ a novel wireless underwater acoustic communication system for transmitting data and triangulating their positions.
Digital versions of these little robots got their own test, not in a pool but in a computer simulation. In an environment with the same pressure and gravity they would likely encounter on Europa, a virtual swarm of 5-inch-long (12-centimeter-long) robots repeatedly went looking for potential signs of life. The computer simulations helped determine the limits of the robots’ abilities to collect science data in an unknown environment, and they led to the development of algorithms that would enable the swarm to explore more efficiently.
The simulations also helped the team better understand how to maximize science return while accounting for tradeoffs between battery life (up to two hours), the volume of water the swimmers could explore (about 3 million cubic feet, or 86,000 cubic meters), and the number of robots in a single swarm (a dozen, sent in four to five waves).
In addition, a team of collaborators at Georgia Tech in Atlanta fabricated and tested an ocean composition sensor that would enable each robot to simultaneously measure temperature, pressure, acidity or alkalinity, conductivity, and chemical makeup. Just a few millimeters square, the chip is the first to combine all those sensors in one tiny package.
Of course, such an advanced concept would require several more years of work, among other things, to be ready for a possible future flight mission to an icy moon. In the meantime, Schaler imagines SWIM robots potentially being further developed to do science work right here at home: supporting oceanographic research or taking critical measurements underneath polar ice.
More About SWIM
Caltech manages JPL for NASA. JPL’s SWIM project was supported by Phase I and II funding from NASA’s Innovative Advanced Concepts (NIAC) program under the agency’s Space Technology Mission Directorate. The program nurtures visionary ideas for space exploration and aerospace by funding early-stage studies to evaluate technologies that could transform future NASA missions. Researchers across U.S. government, industry, and academia can submit proposals.
How the SWIM concept was developed Learn about underwater robots for Antarctic climate science See NASA’s network of ready-to-roll mini-Moon rovers News Media Contact
Melissa Pamer
Jet Propulsion Laboratory, Pasadena, Calif.
626-314-4928
melissa.pamer@jpl.nasa.gov
2024-162
Share
Details
Last Updated Nov 20, 2024 Related Terms
Europa Jet Propulsion Laboratory NASA Innovative Advanced Concepts (NIAC) Program Ocean Worlds Robotics Space Technology Mission Directorate Technology Explore More
5 min read Making Mars’ Moons: Supercomputers Offer ‘Disruptive’ New Explanation
Article 1 hour ago 4 min read From Houston to the Moon: Johnson’s Thermal Vacuum Chamber Tests Lunar Solar Technology
Article 19 hours ago 3 min read Northwestern University Takes Top Honors in BIG Idea Lunar Inflatables Challenge
Article 23 hours ago Keep Exploring Discover Related Topics
Missions
Humans in Space
Climate Change
Solar System
View the full article
-
By NASA
Imagine designing technology that can survive on the Moon for up to a decade, providing a continuous energy supply. NASA selected three companies to develop such systems, aimed at providing a power source at the Moon’s South Pole for Artemis missions.
Three companies were awarded contracts in 2022 with plans to test their self-sustaining solar arrays at the Johnson Space Center’s Space Environment Simulation Laboratory (SESL) in Houston, specifically in Chamber A in building 32. The prototypes tested to date have undergone rigorous evaluations to ensure the technology can withstand the harsh lunar environment and deploy the solar array effectively on the lunar surface.
The Honeybee Robotics prototype during lunar VSAT (Vertical Solar Array Technology) testing inside Chamber A at NASA’s Johnson Space Center in Houston.NASA/David DeHoyos The Astrobotic Technology prototype during lunar VSAT testing inside Chamber A at Johnson Space Center. NASA/James Blair In the summer of 2024, both Honeybee Robotics, a Blue Origin company from Altadena, California and Astrobotic Technology from Pittsburgh, Pennsylvania put their solar array concepts to the test in Chamber A.
Each company has engineered a unique solution to design the arrays to withstand the harsh lunar environment and extreme temperature swings. The data collected in the SESL will support refinement of requirements and the designs for future technological advancements with the goal to deploy at least one of the systems near the Moon’s South Pole.
The contracts for this initiative are part of NASA’s VSAT (Vertical Solar Array Technology) project, aiming to support the agency’s long-term lunar surface operations. VSAT is under the Space Technology Mission Directorate Game Changing Development program and led by the Langley Research Center in Hampton, Virginia, in collaboration with Glenn Research Center in Cleveland.
“We foresee the Moon as a hub for manufacturing satellites and hardware, leveraging the energy required to launch from the lunar surface,” said Jim Burgess, VSAT lead systems engineer. “This vision could revolutionize space exploration and industry.”
Built in 1965, the SESL initially supported the Gemini and Apollo programs but was adapted to conduct testing for other missions like the Space Shuttle Program and Mars rovers, as well as validate the design of the James Webb Space Telescope. Today, it continues to evolve to support future Artemis exploration.
Johnson’s Front Door initiative aims to solve the challenges of space exploration by opening opportunities to the public and bringing together bold and innovative ideas to explore new destinations.
“The SESL is just one of the hundreds of unique capabilities that we have here at Johnson,” said Molly Bannon, Johnson’s Innovation and Strategy specialist. “The Front Door provides a clear understanding of all our capabilities and services, the ways in which our partners can access them, and how to contact us. We know that we can go further together with all our partners across the entire space ecosystem if we bring everyone together as the hub of human spaceflight.”
Chamber A remains as one of the largest thermal vacuum chambers of its kind, with the unique capability to provide extreme deep space temperature conditions down to as low as 20 Kelvin. This allows engineers to gather essential data on how technologies react to the Moon’s severe conditions, particularly during the frigid lunar night where the systems may need to survive for 96 hours in darkness.
“Testing these prototypes will help ensure more safe and reliable space mission technologies,” said Chuck Taylor, VSAT project manager. “The goal is to create a self-sustaining system that can support lunar exploration and beyond, making our presence on the Moon not just feasible but sustainable.”
The power generation systems must be self-aware to manage outages and ensure survival on the lunar surface. These systems will need to communicate with habitats and rovers and provide continuous power and recharging as needed. They must also deploy on a curved surface, extend 32 feet high to reach sunlight, and retract for possible relocation.
“Generating power on the Moon involves numerous lessons and constant learning,” said Taylor. “While this might seem like a technical challenge, it’s an exciting frontier that combines known technologies with innovative solutions to navigate lunar conditions and build a dynamic and robust energy network on the Moon.”
Watch the video below to explore the capabilities and scientific work enabled by the thermal testing conducted in Johnson’s Chamber A facility.
View the full article
-
By European Space Agency
Marking a major milestone in the preparation of Copernicus Sentinel-1C for its scheduled 3 December liftoff, experts have completed the critical and hazardous process of fuelling the satellite.
Once in orbit, Sentinel-1C will extend the Sentinel-1 mission’s legacy, delivering radar imagery to monitor Earth’s changing environment to support a diverse range of applications and scientific research. Additionally, Sentinel-1C brings new capabilities for detecting and monitoring maritime traffic
View the full article
-
By NASA
NASA/Joel Kowsky In this photo, NASA’s SLS (Space Launch System) rocket, carrying the Orion spacecraft, lifts off the pad at Launch Complex 39B at the agency’s Kennedy Space Center in Florida at 1:47 a.m. EST on Nov. 16, 2022. Set on a path to the Moon, this officially began the Artemis I mission.
Since the completion of Orion’s 25.5-day mission around the Moon and back, teams across NASA have been hard at work preparing for the upcoming Artemis II test flight, which will send four astronauts on a 10-day mission around the Moon, paving the way for humans to land on the Moon as part of the Artemis III mission.
Under NASA’s Artemis campaign, the agency will establish the foundation for long-term scientific exploration at the Moon, land the first woman, first person of color, and its first international partner astronaut on the lunar surface, and prepare for human expeditions to Mars for the benefit of all.
Image Credit: NASA/Joel Kowsky
View the full article
-
-
Check out these Videos
Recommended Posts
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.