Sökning: "Polytrend"

Hittade 3 uppsatser innehållade ordet Polytrend.

  1. 1. Global scale patterns and trends in tropospheric NO2 concentrations

    Master-uppsats, Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Författare :Daniel Klingmyr; [2019]
    Nyckelord :Geography; Geographical Information Systems; GIS; Nitrogen dioxide; NO2; Remote sensing; OMI; Spatial patterns; Temporal trends; DBEST; Polytrend; Earth and Environmental Sciences;

    Sammanfattning : Nitrogen dioxide (NO2) is an important air pollutant with both environmental and epidemiological effects. The main aim of this thesis is to explore spatial patterns and temporal trends of tropospheric NO2 concentrations globally using data from the OMI instrument aboard NASA’s Aura spacecraft. LÄS MER

  3. 2. Automated temporal NDVI analysis over the Middle East for the period 1982 - 2010

    Master-uppsats, Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Författare :Hristo Tomov; [2016]
    Nyckelord :trend analysis; NDVI Time series; satellite imagery; change detection; Physical Geography and Ecosystem analysis; GIS; PolyTrend; DBEST; R language; Middle East; Earth and Environmental Sciences;

    Sammanfattning : The NDVI time-series consist of trend, season and noise. Changes in the season component are related to climate factors and they happen gradually over long period of time. The changes in the trend component are often due to human activities, fires and etc. LÄS MER

  4. 3. Developing a web-based system to visualize vegetation trends by a nonlinear regression algorithm

    Master-uppsats, Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Författare :Yufei Wei; [2016]
    Nyckelord :PolyTrend; nonlinear regression algorithm; vegetation trends; Physical Geography and Ecosystem Analysis; NDVI; Web Development; Django; MATLAB; Python; Earth and Environmental Sciences;

    Sammanfattning : Comparing with traditional linear regression methods that used to monitor vegetation trends, a nonlinear regression algorithm (PolyTrend) developed by Jamali et al. (2014) can provide more accurate information of vegetation trends by fitting a polynomial line with a degree of up to three for ASCII-formed time-series NDVI (Normalized Difference Vegetation Index) dataset of a single pixel. LÄS MER