Sökning: "crop reflectance"

Hittade 4 avhandlingar innehållade orden crop reflectance.

1. 1. Hyperspectral Image Generation, Processing and Analysis

   Författare :Hamed Hamid Muhammed; Ewert Bengtsson; Tommy Lindell; Erkki Oja; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bildanalys; hyperspectral imaging; colour filter mosaics; remote sensing; crop reflectance; surface water quality; disease severity; plant density; linear system of equations; waste water detection; chlorophyll a; suspended paticulate matter; weighted fixed neural networks; weighted incremental neural networks; camera spectrometer; Bildanalys; Image analysis; Bildanalys;

   Sammanfattning : Hyperspectral reflectance data are utilised in many applications, where measured data are processed and converted into physical, chemical and/or biological properties of the target objects and/or processes being studied. It has been proven that crop reflectance data can be used to detect, characterise and quantify disease severity and plant density. LÄS MER

3. 2. Measuring and modelling parameters from hyperspectral sensors for site-specific crop protection

   Författare :Anders Larsolle; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

   Sammanfattning : This thesis sought to optimise systems for plant protection in precision agriculture through developing a field method for estimating crop status parameters from hyperspectral sensors, and an empirical model for estimating the required herbicide dose in different parts of the field. The hyperspectral reflectance measurements in the open field took the form of instantaneous spectra recording using an existing method called feature vector based analysis (FVBA), which was applied on disease severity. LÄS MER

4. 3. Monitoring biodiversity in cultural landscapes: development of remote sensing- and GIS-based methods

   Författare :Jonas Dalmayne; Institutionen för naturgeografi och ekosystemvetenskap; []
   Nyckelord :Remote sensing; statistical modeling; spatial scales; partial least squares; support vector machines; grazed grasslands; LULC; HySpex; Worldview-2; Landsat; heterogeneity; landscape complexity; plant species diversity;

   Sammanfattning : In this thesis, I explore the relationships between structural and compositional landscape properties, and species diversity, using remotely sensed data on a variety of spatial scales. The thesis shows that increased landscape heterogeneity, measured using environmental and spectral variables that were used both separately and combined, is generally positively related to plant species richness. LÄS MER

5. 4. Primary Production in African Drylands : Quantifying Supply and Demand Using Earth Observation and Socio-ecological Data

   Författare :Abdulhakim Abdi; Institutionen för naturgeografi och ekosystemvetenskap; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Net primary production; Africa; Drylands; Coupled human and natural systems; Human-Environment Relations; Food security; Earth observation; Remote Sensing;

   Sammanfattning : The human-environment connection in the mostly rural drylands of sub-Saharan Africa forms a complex, interlinked system that provides ecosystem services. This system is susceptible to climatic variability that impacts the supply of its products, and high population growth, which impacts the demand for these products. LÄS MER