Validation of GPS atmospheric water vapor with WVR data in satellite tracking mode

Abstract. Slant-integrated water vapor (SIWV) data derived from GPS STDs (slant total delays), which provide the spatial information on tropospheric water vapor, have a high potential for assimilation to weather models or for nowcasting or reconstruction of the 3-D humidity field with tomographic techniques. Therefore, the accuracy of GPS STD is important, and independent observations are needed to estimate the quality of GPS STD. In 2012 the GFZ (German Research Centre for Geosciences) started to operate a microwave radiometer in the vicinity of the Potsdam GPS station. The water vapor content along the line of sight between a ground station and a GPS satellite can be derived from GPS data and directly measured by a water vapor radiometer (WVR) at the same time. In this study we present the validation results of SIWV observed by a ground-based GPS receiver and a WVR. The validation covers 184 days of data with dry and wet humidity conditions. SIWV data from GPS and WVR generally show good agreement with a mean bias of −0.4 kg m−2 and an rms (root mean square) of 3.15 kg m−2. The differences in SIWV show an elevation dependent on an rms of 7.13 kg m−2 below 15° but of 1.76 kg m−2 above 15°. Nevertheless, this elevation dependence is not observed regarding relative deviations. The relation between the differences and possible influencing factors (elevation angles, pressure, temperature and relative humidity) are analyzed in this study. Besides the elevation, dependencies between the atmospheric humidity conditions, temperature and the differences in SIWV are found.

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GPS tomography: validation of reconstructed 3-D humidity fields with radiosonde profiles

Annales Geophysicae ◽

10.5194/angeo-31-1491-2013 ◽

2013 ◽

Vol 31 (9) ◽

pp. 1491-1505 ◽

Cited By ~ 11

Author(s):

M. Shangguan ◽

M. Bender ◽

M. Ramatschi ◽

G. Dick ◽

J. Wickert ◽

...

Keyword(s):

Spatial Distribution ◽

Water Vapor ◽

Tomographic Reconstruction ◽

Radiosonde Data ◽

Total Delay ◽

Temporal And Spatial Distribution ◽

Spatial Coverage ◽

Independent Observations ◽

Determination System

Abstract. Water vapor plays an important role in meteorological applications; GeoForschungsZentrum (GFZ) therefore developed a tomographic system to derive 3-D distributions of the tropospheric water vapor above Germany using GPS data from about 300 ground stations. Input data for the tomographic reconstructions are generated by the Earth Parameter and Orbit determination System (EPOS) software of the GFZ, which provides zenith total delay (ZTD), integrated water vapor (IWV) and slant total delay (STD) data operationally with a temporal resolution of 2.5 min (STD) and 15 min (ZTD, IWV). The water vapor distribution in the atmosphere is derived by tomographic reconstruction techniques. The quality of the solution is dependent on many factors such as the spatial coverage of the atmosphere with slant paths, the spatial distribution of their intersections and the accuracy of the input observations. Independent observations are required to validate the tomographic reconstructions and to get precise information on the accuracy of the derived 3-D water vapor fields. To determine the quality of the GPS tomography, more than 8000 vertical water vapor profiles at 13 German radiosonde stations were used for the comparison. The radiosondes were launched twice a day (at 00:00 UTC and 12:00 UTC) in 2007. In this paper, parameters of the entire profiles such as the wet refractivity, and the zenith wet delay have been compared. Before the validation the temporal and spatial distribution of the slant paths, serving as a basis for tomographic reconstruction, as well as their angular distribution were studied. The mean wet refractivity differences between tomography and radiosonde data for all points vary from −1.3 to 0.3, and the root mean square is within the range of 6.5–9. About 32% of 6803 profiles match well, 23% match badly and 45% are difficult to classify as they match only in parts.

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Half-year Comparison of Precipitable Water Vapor Retrieved with Novel Ground-based Microwave Radiometer and GPS Receiver at Tsukuba and Numerical Weather Analysis Data

Proceedings of the 2019 International Technical Meeting of The Institute of Navigation ◽

10.33012/2019.16716 ◽

2019 ◽

Author(s):

Ryuichi Ichikawa ◽

Taketo Nagasaki ◽

Osamu Tajima ◽

Hiroshi Takiguchi ◽

Kentaro Araki ◽

...

Keyword(s):

Water Vapor ◽

Microwave Radiometer ◽

Precipitable Water ◽

Analysis Data ◽

Precipitable Water Vapor ◽

Gps Receiver ◽

Numerical Weather

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QUALITY CHECK OF CRISIS MAPS PRODUCED OVER FIVE YEARS BY COPERNICUS EMS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-2-w13-1263-2019 ◽

2019 ◽

Vol XLII-2/W13 ◽

pp. 1263-1268

Author(s):

K. Spasenovic ◽

D. Carrion

Keyword(s):

Disaster Response ◽

Visual Analysis ◽

Spatial Information ◽

Research Centre ◽

Joint Research ◽

Joint Research Centre ◽

Crisis Mapping ◽

Disaster Situation ◽

Quality Check

<p><strong>Abstract.</strong> Crisis mapping is a widely used tool for the digital representation of a disaster situation. It provides stakeholders with spatial information of the crisis describing type and severity of damages, impact on the area and its population. The quality of crisis maps is of a great importance, since the disaster response depends on the provided information. In some cases, in order to deliver a map on time, its quality can be lower than expected. The evaluation of a big sample of rapid maps produced between 2013 and 2017 and collected from open source Copernicus service have been performed. The quality check has been performed by visual analysis, observing around 36 parameters defined in the validation protocol designed at the Joint Research Centre (JRC) of the European Commission. Overall conclusion is that crisis maps produced during the observed period have shown good level of the quality, that can satisfy the need of user. Still, there are some parameters that could be delivered with more details and precision. The results are analysed in details and remarks are presented.</p>

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Comparison of Near–Real Time Estimates of Integrated Water Vapor Derived with GPS, Radiosondes, and Microwave Radiometer

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-1697.1 ◽

2005 ◽

Vol 22 (2) ◽

pp. 201-210 ◽

Cited By ~ 66

Author(s):

Joël Van Baelen ◽

Jean-Pierre Aubagnac ◽

Alain Dabas

Keyword(s):

Water Vapor ◽

Real Time ◽

Global Positioning System ◽

Microwave Radiometer ◽

Positioning System ◽

Gps Receiver ◽

Time Estimates ◽

Global Positioning ◽

Using Data ◽

Gps Observations

Abstract In this study, the authors compare the integrated water vapor (IWV) retrieved with a global positioning system (GPS) receiver, radiosondes (RS), and a microwave radiometer (MWR) using data collected simultaneously during a 3-month campaign in the fall of 2002 in Toulouse, France. In particular for this study, the GPS analysis was performed in near–real time to provide estimates of the IWV in order to evaluate the potential of GPS observations for operational meteorological purposes. Although the three instrument estimates agree quite well together, the IWV estimates retrieved by GPS are generally larger than those of RS, while evidence is shown of a marked diurnal cycle: the differences are larger during the day (up to 2 mm) than at night (less than 0.5 mm). This can be explained by a daytime dry bias of the RS. Regarding the MWR, similar findings but to a lesser extent (differences between 0 and 1 mm) are reported. Furthermore, it has been established that the GPS estimates exhibit a strong dependency upon the IWV values resulting in a 15% faster variation when compared to the other means of IWV estimation in this study.

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Effect of Integrated Nutrient Management on Yield and Quality of Garlic cv. Yamuna Safed-3

Journal of AgriSearch ◽

10.21921/jas.v7i04.19399 ◽

2020 ◽

Vol 7 (04) ◽

Author(s):

A B Priyanshu ◽

M K Singh ◽

Mukesh Kumar ◽

Vipin Kumar ◽

Sunil Malik ◽

...

Keyword(s):

Nutrient Management ◽

Block Design ◽

Quality Parameters ◽

Organic Fertilizers ◽

Research Centre ◽

Yield And Quality ◽

Randomized Block Design ◽

The Impact ◽

Horticultural Research

An experiment was conducted at Horticultural Research Centre, SVP University of Agriculture and Technology, Meerut (UP) during Rabi season of 2018-19 to assess the impact of different INM doses on yield and quality parameters of garlic. A total of ten treatments consisting of combinations of inorganic fertilizers, organic fertilizers and bio-fertilizers like T1- (Control), T2RDF (100:50:50 kg NPK ha-1), T3-RDF + 20 kg sulphur + FYM 20 ton ha-1, T4- RDF + 20 kg sulphur + VC 4 ton ha-1, T5- 75% RDF + 40 kg sulphur + 5 ton FYM ha-1+ PSB 5 kg ha-1, T6-75% RDF + 40 kg sulphur + 2 ton VC + Azotobacter 5 kg ha-1, T7- 75% RDF + 40 kg sulphur + FYM 3 ton + VC 1 ton+ PSB 5 kg + Azotobacter 5kg ha-1, T8- 50% RDF + 40 kg sulphur + FYM 5 ton + VC2 ton + PSB 5 kg ha-1, T9- 50% RDF + 40 kg sulphur + FYM5 ton + VC 2 ton+ Azotobacter 5 kg ha-1and T10- 50% RDF + 40 kg sulphur + FYM 5 ton + VC2 ton + PSB 5 kg + Azotobacter 5 kg ha-1 were used in Randomized Block Design and replicated thrice. Out of these an application of T7 (75% RDF + 40 kg sulphur + FYM3 ton + VC 1 ton ha-1 + PSB 5 kg + Azotobacter 5 kg ha-1) was found to be significantly superior in term of yield and attributing parameters of garlic.

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Geospatial Open Data Usage and Metadata Quality

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi10010030 ◽

2021 ◽

Vol 10 (1) ◽

pp. 30

Author(s):

Alfonso Quarati ◽

Monica De Martino ◽

Sergio Rosim

Keyword(s):

Spatial Information ◽

Open Data ◽

Poor Quality ◽

Data Usage ◽

Open Government Data ◽

Metadata Quality ◽

Geospatial Datasets ◽

Government Data ◽

Determining Factor

The Open Government Data portals (OGD), thanks to the presence of thousands of geo-referenced datasets, containing spatial information are of extreme interest for any analysis or process relating to the territory. For this to happen, users must be enabled to access these datasets and reuse them. An element often considered as hindering the full dissemination of OGD data is the quality of their metadata. Starting from an experimental investigation conducted on over 160,000 geospatial datasets belonging to six national and international OGD portals, this work has as its first objective to provide an overview of the usage of these portals measured in terms of datasets views and downloads. Furthermore, to assess the possible influence of the quality of the metadata on the use of geospatial datasets, an assessment of the metadata for each dataset was carried out, and the correlation between these two variables was measured. The results obtained showed a significant underutilization of geospatial datasets and a generally poor quality of their metadata. In addition, a weak correlation was found between the use and quality of the metadata, not such as to assert with certainty that the latter is a determining factor of the former.

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New Gridded Product for the Total Columnar Atmospheric Water Vapor over Ocean Surface Constructed from Microwave Radiometer Satellite Data

Remote Sensing ◽

10.3390/rs13122402 ◽

2021 ◽

Vol 13 (12) ◽

pp. 2402

Author(s):

Weifu Sun ◽

Jin Wang ◽

Yuheng Li ◽

Junmin Meng ◽

Yujia Zhao ◽

...

Keyword(s):

Water Vapor ◽

Microwave Radiometer ◽

Atmospheric Water Vapor ◽

Global Ocean ◽

Optimal Interpolation ◽

Fusion Product ◽

Mean Deviation ◽

Atmospheric Water ◽

Absolute Deviation ◽

Better Than

Based on the optimal interpolation (OI) algorithm, a daily fusion product of high-resolution global ocean columnar atmospheric water vapor with a resolution of 0.25° was generated in this study from multisource remote sensing observations. The product covers the period from 2003 to 2018, and the data represent a fusion of microwave radiometer observations, including those from the Special Sensor Microwave Imager Sounder (SSMIS), WindSat, Advanced Microwave Scanning Radiometer for Earth Observing System sensor (AMSR-E), Advanced Microwave Scanning Radiometer 2 (AMSR2), and HY-2A microwave radiometer (MR). The accuracy of this water vapor fusion product was validated using radiosonde water vapor observations. The comparative results show that the overall mean deviation (Bias) is smaller than 0.6 mm; the root mean square error (RMSE) and standard deviation (SD) are better than 3 mm, and the mean absolute deviation (MAD) and correlation coefficient (R) are better than 2 mm and 0.98, respectively.

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Community intervention strategies to reduce the impact of financial strain and promote financial well-being: a comprehensive rapid review

Global Health Promotion ◽

10.1177/1757975920984182 ◽

2021 ◽

Vol 28 (1) ◽

pp. 42-50

Author(s):

Nicole M. Glenn ◽

Lisa Allen Scott ◽

Teree Hokanson ◽

Karla Gustafson ◽

Melissa A. Stoops ◽

...

Keyword(s):

Quality Of Life ◽

Community Intervention ◽

Well Being ◽

Small Sample ◽

Financial Strain ◽

Rapid Review ◽

Research Centre ◽

Future Research ◽

The Impact

Financial well-being describes when people feel able to meet their financial obligations, feel financially secure and are able to make choices that benefit their quality of life. Financial strain occurs when people are unable to pay their bills, feel stressed about money and experience negative impacts on their quality of life and health. In the face of the global economic repercussions of the COVID-19 pandemic, community-led approaches are required to address the setting-specific needs of residents and reduce the adverse impacts of widespread financial strain. To encourage evidence-informed best practices, a provincial health authority and community-engaged research centre collaborated to conduct a rapid review. We augmented the rapid review with an environmental scan and interviews. Our data focused on Western Canada and was collected prior to the pandemic (May–September 2019). We identified eight categories of community-led strategies to promote financial well-being: systems navigation and access; financial literacy and skills; emergency financial assistance; asset building; events and attractions; employment and educational support; transportation; and housing. We noted significant gaps in the evidence, including methodological limitations of the included studies (e.g. generalisability, small sample size), a lack of reporting on the mechanisms leading to the outcomes and evaluation of long-term impacts, sparse practice-based data on evaluation methods and outcomes, and limited intervention details in the published literature. Critically, few of the included interventions specifically targeted financial strain and/or well-being. We discuss the implications of these gaps in addition to possibilities and priorities for future research and practice. We also consider the results in relation to the COVID-19 pandemic and its economic consequences.

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