A User Needs Assessment for the next Mass Change Satellite Mission

2020 ◽  
Author(s):  
Margaret Srinivasan ◽  
Matthew Rodell ◽  
John Reager ◽  
Bradley Doorn ◽  
Laura Rogers
Keyword(s):  
Spatial Scales ◽  
Mass Change ◽  
Mission Design ◽  
Groundwater Depletion ◽  
User Needs ◽  
Satellite Mission ◽  
Flood Prediction ◽  
User Community ◽  
User Communities ◽  
Data Products

<p>Planning is underway for development of the next NASA Mass Change satellite mission, as identified in the National Science Foundation’s 2017-2027 Decadal Survey for Earth Science and Applications from Space  (Decadal Survey). NASA has identified a Mass Change Designated Observable (MCDO) Study Team to evaluate satellite mission architectures that could optimally support a range of science and applications needs of user communities (both research and operational) of future mass change missions (i.e., successors to the GRACE and GRACE Follow On missions). The primary science objective of the MCDO, as identified in the Decadal Survey, is the continued measurement of changes in the Earth’s dynamic gravity field over time. The Decadal Survey also emphasizes applications of the mission data products as a major focus, in addition to science outcomes. </p><p>Operational use and societal benefit derived from the GRACE and GRACE FO data and information products demonstrate the value of these missions. Applications include drought monitoring, quantification of groundwater depletion, flood prediction, and thermal expansion of the ocean, which contributes to sea level rise, to name a few. In order to effectively identify the observational product requirements of future gravity mission applications data users and to develop actionable objectives for mission design, a Mass Change Mission Applications survey was developed. Information on user needs, current uses, and capabilities derived from the survey have provided insights as to desired or required spatial scales, data latency, data formats, and technical capabilities of the users, as well as how to prioritize tradeoffs. The survey focused on evaluating the needs of a broad range of existing and potential user communities in order to incorporate these needs into mission design and architecture studies that are underway.</p><p>The survey comprises general questions about requirements for a given application, and data use and demographic information to help characterize aspects of the user community. Analyses of the survey results are now being used to inform potential mission architecture designs, evaluate tradeoffs, and ensure that the data products are optimized for a broad user community.</p>

Applications Program Status for the Mass Change Decadal Observable Mission Study

2020 ◽  
Author(s):  
Margaret Srinivasan ◽  
John T. Reager ◽  
Carmen Böening ◽  
Matthew Rodell ◽  
Rosemary Baize ◽  
...  
Keyword(s):  
Gravity Data ◽  
Community Outreach ◽  
Mass Change ◽  
Satellite Gravity ◽  
User Community ◽  
Formal Program ◽  
User Communities ◽  
Data Products ◽  
Study Team ◽  
The Impact

<p>NASA has identified a Mass Change Designated Observable (MCDO) Study Team to develop the next NASA Mass Change satellite mission, as recommended by the National Academy of Sciences’ 2017-2027 Decadal Survey for Earth Science and Applications from Space (DS). A key requisite of the MCDO mission is that, in addition to optimizing science objectives and programmatic factors (i.e., as cost and risk), it must support a range of operational and applied science uses and user communities beyond the research communities.  </p> <p>Continued measurement of changes in the Earth’s dynamic gravity field over time, as accomplished by the GRACE and GRACE Follow-On missions, is the primary science objective of the MCDO. The DS also emphasizes applications-oriented science and data products that are more responsive to evolving societal needs. Consequently, the MC Applications Team (MCAT) was assembled from among NASA Earth and gravimetry science and applications specialists to identify existing and potential operational uses of these new satellite gravity observations. A key component of this work is focused on optimizing outcomes of and return on NASA’s investment in the new MCDO mission by developing a formal program to engage with user communities beyond the traditional research community and to reach new users and audiences, especially private sector and non-profits.</p> <p>In order to provide value to a broader audience, user community needs (i.e., data types and format, latency and spatial resolution requirements, and others) are being assessed to inform mission design and data processing decisions through incorporation into a science and applications traceability matrix (SATM) developed by the MCDO Study Team. In addition, a value framework is utilized to analyze the value of each mission architecture as defined by its provided benefits relative to its associated cost and risk. The value framework enables the evaluation of the science and programmatic benefits of the concepts using a transparent and objective process.</p> <p>MCAT planning elements for user engagement includes;</p> <ul> <li>Leveraging existing work and resources, based on the GRACE Missions Applications Plan, provides an initial framework for identification and engagement of existing and potential uses and users of gravity mission data.</li> <li>MCDO ‘Mass Change Mission Applications Survey' (tinyurl.com/MassChangeSurvey); This activity has provided important insights into who the current user communities are and their priority needs. The survey queries resolution and accuracy requirements, data use, and demographic information to help characterize user communities. Analyses of results have been used to ensure that the MC data products are optimized for a broad user community.</li> <li>Direct non-research user community outreach and engagement to identify new users who would find value in new satellite gravity data and observations. Focus groups and workshops will be conducted to gage data needs and to better understand the impact of gravimetric data for new users.</li> <li>NASA is developing a Community Assessment Report (CAR) that will include information on existing and potential new users of MC data products and how to maximize benefits for those users.</li> <li>Training</li> </ul> <p>The presentation will highlight progress and how members of the broader applications community can provide inputs to the MCAT.</p>

scholarly journals Groundwater Depletion Signals in the Beqaa Plain, Lebanon: Evidence from GRACE and Sentinel-1 Data

2021 ◽  
Vol 13 (5) ◽  
pp. 915
Author(s):  
Elias C. Massoud ◽  
Zhen Liu ◽  
Amin Shaban ◽  
Mhamad Hage
Keyword(s):  
Snow Water Equivalent ◽  
Water Storage ◽  
Hydrologic Cycle ◽  
Groundwater Depletion ◽  
Satellite Mission ◽  
Groundwater Storage ◽  
Significant Drop ◽  
Monitoring Wells ◽  
High Productivity ◽  
Soil Moisture Storage

Regions with high productivity of agriculture, such as the Beqaa Plain, Lebanon, often rely on groundwater supplies for irrigation demand. Recent reports have indicated that groundwater consumption in this region has been unsustainable, and quantifying rates of groundwater depletion has remained a challenge. Here, we utilize 15 years of data (June 2002–April 2017) from the Gravity Recovery and Climate Experiment (GRACE) satellite mission to show Total Water Storage (TWS) changes in Lebanon’s Beqaa Plain. We then obtain complimentary information on various hydrologic cycle variables, such as soil moisture storage, snow water equivalent, and canopy water storage from the Global Land Data Assimilation System (GLDAS) model, and surface water data from the largest body of water in this region, the Qaraaoun Reservoir, to disentangle the TWS signal and calculate groundwater storage changes. After combining the information from the remaining hydrologic cycle variables, we determine that the majority of the losses in TWS are due to groundwater depletion in the Beqaa Plain. Results show that the rate of groundwater storage change in the West Beqaa is nearly +0.08 cm/year, in the Rashaya District is −0.01 cm/year, and in the Zahle District the level of depletion is roughly −1.10 cm/year. Results are confirmed using Sentinel-1 interferometric synthetic aperture radar (InSAR) data, which provide high-precision measurements of land subsidence changes caused by intense groundwater usage. Furthermore, data from local monitoring wells are utilized to further showcase the significant drop in groundwater level that is occurring through much of the region. For monitoring groundwater storage changes, our recommendation is to combine various data sources, and in areas where groundwater measurements are lacking, we especially recommend the use of data from remote sensing.

scholarly journals King-Hele orbit theory for periodic orbit and attitude variations

2020 ◽  
Vol 501 (1) ◽  
pp. 1168-1187
Author(s):  
Vishal Ray ◽  
Daniel J Scheeres
Keyword(s):  
Drag Coefficient ◽  
Dynamic Parameter ◽  
Mission Design ◽  
Fourier Series Expansion ◽  
Satellite Orbits ◽  
Physical Interaction ◽  
Satellite Mission ◽  
Simplifying Assumptions ◽  
Time Variations ◽  
Specific Factors

ABSTRACT The analytical theory of satellite orbits in an atmosphere developed by King-Hele remains widely in use for satellite mission design because of its accurate approximation to numerical integration under simplifying assumptions. Over the course of six decades, modifications to the theory have addressed many of its weaknesses. However, in all subsequent modifications of the original theory, the assumption of a constant drag-coefficient has been retained. The drag-coefficient is a dynamic parameter that governs the physical interaction between the atmosphere and the satellite and depends on ambient as well as satellite specific factors. In this work, Fourier series expansion models of the drag-coefficient are incorporated in the original King-Hele theory to capture time-variations of the drag-coefficient in averaging integrals. The modified theory is validated through simulations that demonstrate the attained improvements in approximating numerical results over the original King-Hele formulation.

A Distinct Type of Online Group for Customer Knowledge Innovation: The Virtual Product User Community

Libri ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xuguang Li ◽  
Andrew Cox
Keyword(s):  
Virtual Communities ◽  
Virtual Community ◽  
Distinct Type ◽  
Technical Problems ◽  
User Community ◽  
Customer Group ◽  
Knowledge Innovation ◽  
Classification Framework ◽  
User Communities ◽  
Virtual Product

Abstract Among online communities of customers there are a number of different types of group that need to be distinguished. One interesting type are virtual product user communities, i.e. company sponsored online forums where product users share usage experience and collaboratively construct new knowledge to solve technical problems. The purpose of this paper is to show that these “virtual product user communities” are a distinct type of customer group with knowledge innovation capability. The research adopts a method combining observation and content analysis of discussion threads where technical problems are solved, complemented by thematic analysis of interviews with forum members to explore its character, especially its knowledge related attributes. The paper confirms empirically that the virtual product user community is a distinct type of virtual community and can be differentiated from other virtual communities of consumers. In addition, an enhanced classification framework, extending Porter’s (2004) classic 5Ps model, is proposed to highlight knowledge-related activities in virtual communities. Of particular interest is that the findings suggest that knowledge-related activities should be considered as an important attribute in defining and classifying virtual communities. In terms of practical implications, it is recommended that the virtual product user community should be given appropriate support from top management in order to fully exploit its knowledge innovation value. Moreover, tailored facilitation strategies to promote knowledge construction activities and community development can be developed in accordance with its unique attributes. The paper precisely distinguishes one specific type of innovative virtual community consisting of product users from other online customer communities. Moreover, it outlines a revised virtual community classification framework, which can be widely applied in analysing features of online groups. Its key attribute of knowledge-related activity redirects attention to virtual communities’ knowledge innovation capabilities.

Building digital collections in a public university library in Ghana: priority-setting and user needs assessment

2014 ◽  
Vol 33 (2) ◽  
pp. 38-45 ◽  
Author(s):  
Nesba Yaa Anima Adzobu
Keyword(s):  
Needs Assessment ◽  
Digital Library ◽  
Priority Setting ◽  
Digital Libraries ◽  
Academic Library ◽  
User Needs ◽  
Digital Collections ◽  
Content Type ◽  
User Communities ◽  
Library User

Purpose – Although user needs assessment is an intrinsic element of service quality delivery in digital libraries (DLs), not much has been written on this topic in the context of African universities. This is understandable as academic digital libraries in Africa are rather nascent. Even so, the most frequently-used needs assessment methods do not directly involve the users. This study aims to assess priority setting by academic library administrators and the needs of patrons of digital collections of a public university library in Ghana. Design/methodology/approach – Analysis of official university documents and interviews with digital library patrons at the University of Cape Coast (UCC) in Ghana were carried out between September, 2011 and January, 2012. Five research questions were asked: what are the current conditions of the UCC digital library project, the user communities and their needs, what are the priorities set by the university administrators and library leaders at the UCC and the state of technological readiness in place and what are needed by the UCCDL. Also, what is the extent of collaboration by interested parties in the UCCDL? Findings – Three general digital library user communities were identified, that is, UCCDL staff- this community was composed of experts in both digital library systems and content, characterized as heavy users of the existing systems, as knowledgeable about articulated (formalized) user needs, and able to devote short (usually less than two hours) amounts of time to individual's needs. Next, are scholars and other visitors to the UCCDL – this community was characterized as having high levels of domain expertise and knowledge of library systems. They are also able to devote large but specific amounts of time (days or weeks) to their individual information needs. Visitors/Prospective users- this community was characterized as having varied levels of domain expertise and low levels of library systems knowledge. They are able to devote only short periods of time to their information needs or explorations. These user communities are influenced by diverse preferences, experiences, and knowledge structures. Practical implications – Academic libraries are increasingly advocating local user studies as a way to provide the digital library services that are relevant to the culture and user population of the academic institution. Replicating digital library user studies at the local level can provide information for improving existing services or developing new ones. Originality/value – In African public universities, there is little earlier research on digital library user needs assessments or DL priority-setting by academic library administrators.

scholarly journals Global Mapping of GDP at 1 km2 Using VIIRS Nighttime Satellite Imagery

2019 ◽  
Vol 8 (12) ◽  
pp. 580 ◽  
Author(s):  
Xuantong Wang ◽  
Paul C. Sutton ◽  
Bingxin Qi
Keyword(s):  
Machine Learning ◽  
Socioeconomic Development ◽  
Infrared Imaging ◽  
Learning Algorithm ◽  
Spatial Scales ◽  
Line System ◽  
The Sustainable Development ◽  
Gini Coefficients ◽  
Data Products ◽  
Global Mapping

Frequent and rapid spatially explicit assessment of socioeconomic development is critical for achieving the Sustainable Development Goals (SDGs) at both national and global levels. Over the past decades, scientists have proposed many methods for estimating human activity on the Earth’s surface at various spatiotemporal scales using Defense Meteorological Satellite Program Operational Line System (DMSP-OLS) nighttime light (NTL) data. However, the DMSP-OLS NTL data and the associated processing methods have limited their reliability and applicability for systematic measuring and mapping of socioeconomic development. This study utilized Visible Infrared Imaging Radiometer Suite (VIIRS) NTL and the Isolation Forest machine learning algorithm for more intelligent data processing to capture human activities. We used machine learning and NTL data to map gross domestic product (GDP) at 1 km2. We then used these data products to derive inequality indexes (e.g., Gini coefficients) at nationally aggregate levels. This flexible approach processes the data in an unsupervised manner at various spatial scales. Our assessments show that this method produces accurate subnational GDP data products for mapping and monitoring human development uniformly across the globe.

AIRS/AMSU/HSB on the aqua mission: design, science objectives, data products, and processing systems

2003 ◽  
Vol 41 (2) ◽  
pp. 253-264 ◽  
Author(s):  
H.H. Aumann ◽  
M.T. Chahine ◽  
C. Gautier ◽  
M.D. Goldberg ◽  
E. Kalnay ◽  
...  
Keyword(s):  
Design Science ◽  
Mission Design ◽  
Data Products

scholarly journals ANALYSIS OF WATER MASS VARIATION IN WETLANDS REGIONS USING DATA FROM GRACE SATELLITE MISSION: THE PANTANAL CASE

2016 ◽  
Vol 34 (4) ◽  
Author(s):  
Cecilia Cornero ◽  
Ayelen Pereira ◽  
Ana Cristina Oliveira Cancoro de Matos ◽  
María Cristina Pacino
Keyword(s):  
Spatial Scales ◽  
Transport Processes ◽  
Satellite Mission ◽  
Satellite Gravity ◽  
Earth’S Gravity Field ◽  
Paraguay River ◽  
Using Data ◽  
Gravity Recovery ◽  
Gravity Field Models ◽  
Gravity Mission

ABSTRACT. The natural heritage of biodiversity of the Paraguay river basin is subject to potential impacts due to climate change. To monitor these environments at large spatial scales, the satellite gravity mission GRACE (Gravity Recovery and Climate Experiment) provides time-variable Earth’s gravity field models that reflect the variations due to mass transport processes, like continental...Keywords: water storage, satellite gravity mission, river gauge, rainfall. RESUMO. O patrimônio natural de biodiversidade da bacia do rio Paraguai está sujeito a potenciais impactos das mudanças climáticas. Para monitorar esse ambiente em escala espacial, a missão satelital GRACE (Gravity Recovery and Climate Experiment) fornece modelos do campo de gravidade da Terra variáveis no tempo devido ao processo de transporte de massa, como as variações de armazenamento de água...Palavras-chave: armazenamento de água, missão satelital, cotas do nível d’água, precipitação.

scholarly journals How well are we able to close the water budget at the global scale?

2022 ◽  
Vol 26 (1) ◽  
pp. 35-54
Author(s):  
Fanny Lehmann ◽  
Bramha Dutt Vishwakarma ◽  
Jonathan Bamber
Keyword(s):  
Water Balance ◽  
Balance Equation ◽  
Land Surface ◽  
Water Budget ◽  
Global Scale ◽  
Surface Model ◽  
Catchment Scale ◽  
Satellite Mission ◽  
Water Balance Equation ◽  
Data Products

Abstract. The water budget equation describes the exchange of water between the land, ocean, and atmosphere. Being able to adequately close the water budget gives confidence in our ability to model and/or observe the spatio-temporal variations in the water cycle and its components. Due to advances in observation techniques, satellite sensors, and modelling, a number of data products are available that represent the components of water budget in both space and time. Despite these advances, closure of the water budget at the global scale has been elusive. In this study, we attempt to close the global water budget using precipitation, evapotranspiration, and runoff data at the catchment scale. The large number of recent state-of-the-art datasets provides a new evaluation of well-used datasets. These estimates are compared to terrestrial water storage (TWS) changes as measured by the Gravity Recovery And Climate Experiment (GRACE) satellite mission. We investigated 189 river basins covering more than 90 % of the continental land area. TWS changes derived from the water balance equation were compared against GRACE data using two metrics: the Nash–Sutcliffe efficiency (NSE) and the cyclostationary NSE. These metrics were used to assess the performance of more than 1600 combinations of the various datasets considered. We found a positive NSE and cyclostationary NSE in 99 % and 62 % of the basins examined respectively. This means that TWS changes reconstructed from the water balance equation were more accurate than the long-term (NSE) and monthly (cyclostationary NSE) mean of GRACE time series in the corresponding basins. By analysing different combinations of the datasets that make up the water balance, we identified data products that performed well in certain regions based on, for example, climatic zone. We identified that some of the good results were obtained due to the cancellation of errors in poor estimates of water budget components. Therefore, we used coefficients of variation to determine the relative quality of a data product, which helped us to identify bad combinations giving us good results. In general, water budget components from ERA5-Land and the Catchment Land Surface Model (CLSM) performed better than other products for most climatic zones. Conversely, the latest version of CLSM, v2.2, performed poorly for evapotranspiration in snow-dominated catchments compared, for example, with its predecessor and other datasets available. Thus, the nature of the catchment dynamics and balance between components affects the optimum combination of datasets. For regional studies, the combination of datasets that provides the most realistic TWS for a basin will depend on its climatic conditions and factors that cannot be determined a priori. We believe that the results of this study provide a road map for studying the water budget at catchment scale.

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