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NASA NTRS2026

Spacecraft Water Impurity Monitor, a System for Water Quality Analysis on Exploration Missions Beyond Low Earth Orbit

Exploration missions beyond low-earth-orbit (LEO) will require advanced instrumentation to monitor water quality. Traveling beyond LEO means the transfer of water samples to an Earth-based laboratory for detailed analysis is not feasible. Detailed analysis of water composition during exploration is still necessary, because having the capability to determine the specific organic chemical causing a change in total organic carbon (TOC) or the specific metal or ionic species causing a change in conductivity has the potential to inform the crew health and system management decisions. On a new vehicle such as a lunar or Mars surface habitat or a Mars transit vehicle, finding “new” impurities not seen on ISS should be expected. The key is to identify the impurity so the correct action can be taken. On ISS we can measure TOC, conductivity, and other physical properties but do not have the capability for detailed analysis using vehicle instrumentation. This is acceptable because ISS can send samples down to Earth for further analysis and obtain the detailed composition. The Spacecraft Water Impurity Monitor (SWIM) will provide detailed water quality analysis for missions in which sample down mass is not available. SWIM is a system comprising organic and inorganic analysis modules. For organic chemicals, a gas chromatograph mass spectrometer (GCMS) detects and identifies organic impurities. For inorganic species, a capillary electrophoresis capacitively coupled contactless conductivity detection (CE-C4D) system as well as ion specific electrodes detect and identify metal ions and other inorganic salts / acids. The SWIM technology demonstration project has completed a System Requirements Review (SRR) to finalize detection requirements and is currently working to refine vehicle interface requirements for a future technology demonstration. The project also has begun preliminary flight design activities for the core analyzers in the instrument suite.

Water Monitoring↗

NASA NTRS2026

Spacecraft Water Impurity Monitor, a System for Water Quality Analysis on Exploration Missions Beyond Low Earth Orbit

Water Monitoring↗

NASA NTRS1990

Atmosphere and water quality monitoring on Space Station Freedom

In Space Station Freedom air and water will be supplied in closed loop systems. The monitoring of air and water qualities will ensure the crew health for the long mission duration. The Atmosphere Composition Monitor consists of the following major instruments: (1) a single focusing mass spectrometer to monitor major air constituents and control the oxygen/nitrogen addition for the Space Station; (2) a gas chromatograph/mass spectrometer to detect trace contaminants; (3) a non-dispersive infrared spectrometer to determine carbon monoxide concentration; and (4) a laser particle counter for measuring particulates in the air. An overview of the design and development concepts for the air and water quality monitors is presented.

Niu, William↗

NASA NTRS2009

Development and Certification of Station Development Test Objective (SDTO) Experiment # 15012-U, "Near RealTime Water Quality Monitoring Demonstration for ISS Biocides Using Colorimetric Solid Phase Extraction (CSPE)"

Scientists and engineers from the Wyle Integrated Science and Engineering Group are working with researchers at the University of Utah and Iowa State University to develop and certify an experimental water quality monitoring kit based on Colorimetric Solid Phase Extraction (CSPE). The kit will be launched as a Station Development Test Objective (SDTO) experiment and evaluated on the International Space Station (ISS) to determine the acceptability of CSPE technology for routine inflight water quality monitoring. Iodine and silver, the biocides used in the US and Russian on-orbit water systems, will serve as test analytes for the technology evaluation. This manuscript provides an overview of the CSPE SDTO experiment and details the development and certification of the experimental water quality monitoring kit. Initial results from reagent and standard solution stability testing and environmental testing performed on the kit hardware are also reported.

Gazda, Daniel B.↗

NASA NTRS1975

Utilization of LANDSAT data for water quality surveys in the Choptank River

Computer processing of LANDSAT-1 multispectral digital data demonstrated the applicability of remotely sensed data to water quality survey in the Choptank River. Water classes derived by automated analysis correlate to river nuisance levels of chlorophyll a and sediment loading as defined by the Maryland Department of Water Resources and the U.S. Corps of Engineers. Results indicate that an increase in chlorophyll a concentration corresponds, relative to MSS 5, to decreases in 4 and increases in 6 relative to the trends with increasing sediment load. It appears that for the purpose of water quality analysis, under favorable atmospheric conditions, only MSS 4, 5 and 6 are necessary.

Johnson, J. M.↗

NASA NTRS2021

Follow-up Water Quality Analysis at the Little Patuxent River in Anne Arundel County, Maryland andImpact to the Health of the Chesapeake Bay

In accordance with the federal Clean Water Act, it is of utmost importance to identify impaired water bodies and subsequently implement Total Maximum Daily Loads (TMDL) as needed to achieve desirable water quality standards. One of these water bodies include the Little Patuxent River (LPR) in the Anne Arundel and Howard Counties in Maryland, which is the subject of this report. In the 1996, 1998, and then 2006 Maryland Integrated Report, the LPR was found to be impaired by nutrients, bacteria, suspended sediments, and cadmium (Cd). As a result, TMDLs were created to limit factors that were contributing to these problems (Maryland Department of the Environment 2011, December). But later in 2008 and 2009, water quality analyses (WQAs) found that the LPR’s condition had improved. From a Category 5 Cd and phosphorus classification in 1996 it was reduced to Category 2 in 2008 for Cd and in 2009 for phosphorus (Maryland Department of the Environment 2011, December). However, it has been more than a decade since the last WQA and the environmental conditions may have changed. This lack of testing could result in untracked, accumulated damages to the overall health of the LPR. We present testing results for the 13 site locations on the LPR to evaluate turbidity, pH, phosphates, nitrates, water temperature, dissolved oxygen (D.O.), coliform bacteria, and cadmium concentrations in sediments. We will also present next steps including remediation strategies.

Aaban Syed↗

NASA NTRS1994

Monitoring changes in Greater Yellowstone Lake water quality following the 1988 wildfires

The fires that burned the Greater Yellowstone Area (GYA) during the summer of 1988 were the largest ever recorded for the region. Wildfire can have profound indirect effects on associated aquatic ecosystems by increased nutrient loading, sediment, erosion, and runoff. Satellite remote sensing and water quality sampling were used to compare pre- versus post-fire conditions in the GYA's large oliotrophic (high transparency, low productivity) lakes. Inputs of suspended sediment to Jackson Lake appear to have increased. Yellowstone Lake has not shown any discernable shift in water quality. The insights gained separately from the Landsat Thematic and NOAA Advanced Very High Resolution Radiometer (AVHRR) remote sensing systems, along with conventional in-situ sampling, can be combined into a useful water quality monitoring tool.

Lathrop, Richard G., Jr.↗

NASA NTRSDate not supplied

Validation of Machine Learning Algorithms for Hyperspectral Inversion of Common Water Quality Indicators

The upcoming transition to a diverse suite hyperspectral airborne and orbiting optical sensors will provide an unprecedented opportunity to measure inland water quality characteristics at a fidelity not previously achievable. This presentation will assess prototype deep learning models trained on synthetic hyperspectral data and validated with collocated in-situ measurements. Synthesized data is becoming increasingly popular for use in data-driven approaches to complex problems, and can compliment real data to increase performance on complex and unusual phenomenon, reduce or test bias, and experiment to demonstrate explainability. We will present insights from hyperspectral inversions of Chlorophyl-a, Phycocyanin, and concentration of non-algal particles using selected orbiting and airborne sensors over diverse, optically complex aquatic scenarios. We analyze how various optical water types affect fidelity of results and where improvements can be made as we prototype for globally operational water quality algorithms which can be leveraged by upcoming hyperspectral missions such as the Surface Biology and Geology (SBG) mission.

Surface Biology and Geology (SBG)↗

NASA NTRS2022

San Diego Water Resources: Monitoring Pollution Plumes due to Storm and Wastewater Runoff in the San Diego Bay and Tijuana River Estuary to Inform Water Quality Management

Stormwater and wastewater runoff are a large source of pollutant discharge along the southern California coast and are a major concern to the health of local communities and ecosystems. In partnership with the Tijuana River National Estuarine Research Reserve and the California Department of Environmental Quality, NASA DEVELOP utilized satellite imagery to visualize and analyze the water quality of the Tijuana Estuary and southern California coast after major storm and wastewater events. Using Landsat 8 Operational Land Imager (OLI) and Sentinel-2 Multispectral Instrument (MSI), we estimated the extent and severity of plumes released from the Tijuana River Estuary. We used remotely sensed turbidity to map the extent of plumes, and used remotely sensed turbidity, Chlorophyll-a (chl-a), and colored dissolved organic matter (CDOM) to quantify and visualize stormwater, wastewater, and mixed plumes from 2013 to 2022. Furthermore, remotely sensed CDOM, turbidity, and chl-a were validated with in-situ data from NOAA and the San Diego Public Utilities in the San Diego coastal area to evaluate the accuracy of water quality data derived from satellite imagery. End products of this project include maps of stormwater, wastewater, and mixed plumes, tables illustrating the average area, CDOM, turbidity, and chl-a of each plume type, and validation graphs between satellite and in-situ data sources. These end products informed the environmental management of the Tijuana River National Estuarine Research Reserve and the public beaches in San Diego.

Ethan Gates↗

NASA NTRS2011

In-Flight Water Quality Monitoring on the International Space Station (ISS): Measuring Biocide Concentrations with Colorimetric Solid Phase Extraction (CSPE)

The colorimetric water quality monitoring kit (CWQMK) was delivered to the International Space Station (ISS) on STS-128/17A and was initially deployed in September 2009. The kit was flown as a station development test objective (SDTO) experiment to evaluate the acceptability of colorimetric solid phase extraction (CSPE) technology for routine water quality monitoring on the ISS. During the SDTO experiment, water samples from the U.S. water processor assembly (WPA), the U.S. potable water dispenser (PWD), and the Russian system for dispensing ground-supplied water (SVO-ZV) were collected and analyzed with the CWQMK. Samples from the U.S. segment of the ISS were analyzed for molecular iodine, which is the biocide added to water in the WPA. Samples from the SVOZV system were analyzed for ionic silver, the biocide used on the Russian segment of the ISS. In all, thirteen in-flight analysis sessions were completed as part of the SDTO experiment. This paper provides an overview of the experiment and reports the results obtained with the CWQMK. The forward plan for certifying the CWQMK as operational hardware and expanding the capabilities of the kit are also discussed.

Gazda, Daniel B.↗

NASA NTRS1978

The blue-to-green reflectance ratio and lake water quality

Correlations between the relative values of the blue and green reflectances of a lake and water quality indices, such as depth of photic zone, Secchi disk transparency, attenuation coefficient, and chlorophyll concentration, have been observed during an intensive satellite, aircraft, and surface vessel study of Lake Ontario and Conesus Lake. Determinations of blue and green reflectances from Skylab S190A color imagery are in excellent agreement with values obtained from small-scale color imagery from aircraft. Further, the accuracy of the satellite data appears within that required for extrapolation to the water quality indices. The study has also determined that changes in chlorophyll, lignin, and humic acid concentration can be discriminated by the behavior of the blue-to-green reflectance ratio and the reflectances of the green and red bands.

Piech, K. R.↗

NASA NTRS1976

A Landsat study of water quality in Lake Okeechobee

This paper uses multiple regression techniques to investigate the relationship between Landsat radiance values and water quality measurements. For a period of over one year, the Central and Southern Florida Flood Control District sampled the water of Lake Okeechobee for chlorophyll, carotenoids, turbidity, and various nutrients at the time of Landsat overpasses. Using an overlay map of the sampling stations, Landsat radiance values were measured from computer compatible tapes using a GE image 100 and averaging over a 22-acre area at each station. These radiance values in four bands were used to form a number of functions (powers, logarithms, exponentials, and ratios), which were then compared with the ground measurements using multiple linear regression techniques. Several dates were used to provide generality and to study possible seasonal variations. Individual correlations were presented for the various water quality parameters and best fit equations were examined for chlorophyll and turbidity. The results and their relationship to past hydrological research were discussed.

Gervin, J. C.↗

NASA NTRS1974

Aircraft and satellite monitoring of water quality in Lake Superior near Duluth

Satellite images and low altitude aerial photographs often show vivid discolorations in water bodies. Extensive laboratory analysis shows that water reflectance, which causes brightness on aerial images, positively correlates to the water quality parameter of turbidity, which on a particular day correlates to suspended solids. Work with low altitude photography on three overcast days and with ERTS images on five clear days provides positive correlation of image brightness to the high turbidity and solids which are present in Lake Superior near Duluth over 50% of the time. Proper use of aerial images would have shown that an $8,000,000 drinking water intake constructed in the midst of this unpotable, turbid water should have been located 6 miles north in clear, usable water. Noise effects such as skylight reflection, atmospheric effects, and depth penetration also must be understood for operational use of remote sensing for water quality monitoring and are considered in the paper.

Scherz, J. P.↗

NASA NTRS1976

Remote sensing of land use and water quality relationships - Wisconsin shore, Lake Michigan

This investigation assessed the utility of remote sensing techniques in the study of land use-water quality relationships in an east central Wisconsin test area. The following types of aerial imagery were evaluated: high altitude (60,000 ft) color, color infrared, multispectral black and white, and thermal; low altitude (less than 5000 ft) color infrared, multispectral black and white, thermal, and passive microwave. A non-imaging hand-held four-band radiometer was evaluated for utility in providing data on suspended sediment concentrations. Land use analysis includes the development of mapping and quantification methods to obtain baseline data for comparison to water quality variables. Suspended sediment loads in streams, determined from water samples, were related to land use differences and soil types in three major watersheds. A multiple correlation coefficient R of 0.85 was obtained for the relationship between the 0.6-0.7 micrometer incident and reflected radiation data from the hand-held radiometer and concurrent ground measurements of suspended solids in streams. Applications of the methods and baseline data developed in this investigation include: mapping and quantification of land use; input to watershed runoff models; estimation of effects of land use changes on stream sedimentation; and remote sensing of suspended sediment content of streams. High altitude color infrared imagery was found to be the most acceptable remote sensing technique for the mapping and measurement of land use types.

Haugen, R. K.↗

NASA NTRS1973

Derivation of a three dimensional numerical water quality model for estuary and continental shelf application

A derivation is given for a three dimensional mass transport equation which is appropriate for numerical modeling of estuary and continental shelf water quality variations for both the time dependent and steady state cases. A finite difference approximation to the derived equation is presented and a solution scheme for the resulting equations outlined. Preliminary results are obtained using the model for the extremely simple problems which have analytical solutions. The numerical model, as presented, will provide a scheme to study water quality problems in coastal waters for both steady state and time dependent cases.

Spaulding, M.↗

NASA NTRS1975

The use of LANDSAT-1 imagery for water quality studies in southern Scandinavia

The possibilities of using LANDSAT-1 images for environmental studies, with special references to water quality studies, were investigated by selecting test areas in southern Scandinavia. The MSS images of different bands are compared under the magnification of an Interpretoscope and densitometric analyses are performed in a Schnell-photometer. The possibility of tracing pollution plumes is studied in the Oresund outside Copenhagen. The effect of different sewers and the circulation of the polluted water is analyzed in various situations. The variation in reflectivity of a great number of lakes in South and Middle Sweden is studied by means of densitometric analyses and significant regional differences are found. The correlation with in situ measurements of water quality (turbidity and secchi disc transparency) of the sampled lakes (made by the National Swedish Environment Protection Board) is fairly good.

Hellden, U.↗

NASA NTRS2022

Simultaneous Retrieval of Selected Optical Water Quality Indicators From Landsat-8, Sentinel-2, and Sentinel-3

Constructing multi-source satellite-derived water quality (WQ) products in inland and nearshore coastal waters from the past, present, and future missions is a long-standing challenge. Despite inherent differences in sensors’ spectral capability, spatial sampling, and radiometric performance, research efforts focused on formulating, implementing, and validating universal WQ algorithms continue to evolve. This research extends a recently developed machine-learning (ML) model, i.e., Mixture Density Networks (MDNs) (Pahlevan et al., 2020; Smith et al., 2021), to the inverse problem of simultaneously retrieving WQ indicators, including chlorophyll-a (Chla), Total Suspended Solids (TSS), and the absorption by Colored Dissolved Organic Matter at 440 nm (a cdom (440)), across a wide array of aquatic ecosystems. We use a database of in situ measurements to train and optimize MDN models developed for the relevant spectral measurements (400–800 nm) of the Operational Land Imager (OLI), MultiSpectral Instrument (MSI), and Ocean and Land Color Instrument (OLCI) aboard the Landsat-8, Sentinel-2, and Sentinel-3 missions, respectively. Our two performance assessment approaches, namely hold-out and leave-one-out, suggest significant, albeit varying degrees of improvements with respect to second-best algorithms, depending on the sensor and WQ indicator (e.g., 68%, 75%, 117% improvements based on the hold-out method for Chla, TSS, and a cdom (440), respectively from MSI-like spectra). Using these two assessment methods, we provide theoretical upper and lower bounds on model performance when evaluating similar and/or out-of-sample datasets. To evaluate multi-mission product consistency across broad spatial scales, map products are demonstrated for three near-concurrent OLI, MSI, and OLCI acquisitions. Overall, estimated TSS and a cdom (440) from these three missions are consistent within the uncertainty of the model, but Chla maps from MSI and OLCI achieve greater accuracy than those from OLI. By applying two different atmospheric correction processors to OLI and MSI images, we also conduct matchup analyses to quantify the sensitivity of the MDN model and best-practice algorithms to uncertainties in reflectance products. Our model is less or equally sensitive to these uncertainties compared to other algorithms. Recognizing their uncertainties, MDN models can be applied as a global algorithm to enable harmonized retrievals of Chla, TSS, and a cdom (440) in various aquatic ecosystems from multi-source satellite imagery. Local and/or regional ML models tuned with an apt data distribution (e.g., a subset of our dataset) should nevertheless be expected to outperform our global model.

Machine learning↗

NASA NTRS1973

ERTS-1 Virgin Islands experiment 589: Determine boundaries of ERTS and aircraft data within which useful water quality information can be obtained

The author has identified the following significant results. The boundaries of application of ERTS-1 and aircraft data are established for St. Thomas harbor within which useful water quality information can be obtained. In situ physical, chemical, and biological water quality and benthic data were collected. Moored current meters were employed. Optical measurements of solar irradiance, color test panel radiance and water absorption were taken. Procedures for correlating in situ optical, biological, and chemical data with underflight aircraft I2S data and ERTS-1 MSS scanner data are presented. Comparison of bulk and precision CCT computer printout data for this application is made, and a simple method for geometrically locating bulk data individual pixels based on land-water interface is described. ERTS spacecraft data and I2S aircraft imagery are correlated with optical in situ measurements of the harbor water, with the aircraft green photographic and ERTS-1 MSS-4 bands being the most useful. The biological pigments correlate inversely with the optical data for inshore areas and directly further seaward. Automated computer data processing facilitated analysis.

Coulbourn, W. C.↗