7 research outputs found

    A web map service implementation for the visualization of multidimensional gridded environmental data

    Get PDF
    We describe ncWMS, an implementation of the Open Geospatial Consortium's Web Map Service (WMS) specification for multidimensional gridded environmental data. ncWMS can read data in a large number of common scientific data formats – notably the NetCDF format with the Climate and Forecast conventions – then efficiently generate map imagery in thousands of different coordinate reference systems. It is designed to require minimal configuration from the system administrator and, when used in conjunction with a suitable client tool, provides end users with an interactive means for visualizing data without the need to download large files or interpret complex metadata. It is also used as a “bridging” tool providing interoperability between the environmental science community and users of geographic information systems. ncWMS implements a number of extensions to the WMS standard in order to fulfil some common scientific requirements, including the ability to generate plots representing timeseries and vertical sections. We discuss these extensions and their impact upon present and future interoperability. We discuss the conceptual mapping between the WMS data model and the data models used by gridded data formats, highlighting areas in which the mapping is incomplete or ambiguous. We discuss the architecture of the system and particular technical innovations of note, including the algorithms used for fast data reading and image generation. ncWMS has been widely adopted within the environmental data community and we discuss some of the ways in which the software is integrated within data infrastructures and portals

    A literature review on environmental regulation and policy and quality assurance: A blueprint for the Malaysian food and beverage companies

    Get PDF
    The main objective of this study is to develop a life cycle mode for a process-oriented quality assurance in organizational performance of food and beverage companies.As an iterative and dynamic process, quality assurance is interwoven in the developmental process of food and beverage companies.Through the review of literature s in existence, specifically those that focus on procedures, frameworks, methodology, a process oriented framework is developed around non-linear sequential stages presented as: planning/before, design and production (during), post production and delivery (after).The model is approved through an advanced systematic methods employed in collecting, organizing and generating reports about quality assurance (QA) needed updates or changes. According to the approach of process oriented lifecycle, many studies emphasizes that quality assurance needs a friendly environment that take quality as a key factor and a work value for attaining the objectives of an organization. A practical quality assurance model is then proposed by this study that complies with the guide of food and beverage development phases.In each stage of development, practical steps are recommended. There is great potential in the quality assurance model for its transformation from static, the state of after-the-fact to a state of dynamism and iterative state, thereby improving the ongoing self-improvement culture, rather than compliance of circumstance

    REMOTE SENSING ANALYTICAL GEOSPATIAL OPERATIONS DIRECTLY IN THE WEB BROWSER

    Get PDF
    Current map viewers that run on modern web browsers are mainly requesting images generated on the fly in the server side and transferred in pictorial format that they can display (PNG or JPEG). In OGC WMS standard this is done for the whole map view while in WMTS is done per tiles. The user cannot fine tune personalized visualization or data analysis in the client side. Remote sensing data is structured in bands that are visualize individually (manually adjusting contrast), create RGB combinations or present spectral indices. When these operations are not available in map browsers professional are forced to download hundreds of gigabytes of remote sensing imagery to take a good look at the data before deciding if it fits for a purpose. A possible solution is to create a web service that is able to perform these operations on the server side (https://www.sentinel-hub.com). This paper proposes that the server should communicate the data values to the client in a format that the client can directly process using two new additions in HTML5: canvas edition and array buffers. In the client side, the user can interact with a JavaScript interface changing symbolizations and doing some analytical operations without having to request any data again to the server. As a bonus, the user is able to perform queries to the data in a more dynamic way, applying spatial filters, creating histograms, generating animations of a time series or performing complex calculations among bands of the different loaded datasets

    GeohashTile: Vector Geographic Data Display Method Based on Geohash

    Get PDF
    © 2020 MDPI AG. All rights reserved. In the development of geographic information-based applications for mobile devices, achieving better access speed and visual effects is the main research aim. In this paper, we propose a new geographic data display method based on Geohash, namely GeohashTile, to improve the performance of traditional geographic data display methods in data indexing, data compression, and the projection of different granularities. First, we use the Geohash encoding system to represent coordinates, as well as to partition and index large-scale geographic data. The data compression and tile encoding is accomplished by Geohash. Second, to realize a direct conversion between Geohash and screen-pixel coordinates, we adopt the relative position projection method. Finally, we improve the calculation and rendering efficiency by using the intermediate result caching method. To evaluate the GeohashTile method, we have implemented the client and the server of the GeohashTile system, which is also evaluated in a real-world environment. The results show that Geohash encoding can accurately represent latitude and longitude coordinates in vector maps, while the GeohashTile framework has obvious advantages when requesting data volume and average load time compared to the state-of-the-art GeoTile system
    corecore