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Visibility observations and accurate forecasts are essential in meteorology, requiring a dense network of observation stations. This paper investigates image processing techniques for object detection and visibility determination using static cameras. It proposes a comprehensive method that includes image preprocessing, landmark identification, and visibility estimation, mirroring the observation process of professional meteorological observers. This study validates the visibility observation procedure using the k-nearest neighbors machine learning method across six locations, including four in the Czech Republic, one in the USA, and one in Germany. By comparing our results with professional observations, the paper demonstrates the suitability of the proposed method for operational application, particularly in foggy and low visibility conditions. This versatile method holds potential for adoption by meteorological services worldwide. [ABSTRACT FROM AUTHOR]

The main goals of the following paper are to evaluate the performance of two multispectral airborne sensors and compare their image data with in situ spectral measurements. Moreover, the authors aim to present an enhanced workflow for processing multitemporal image data using both commercial and open-source solutions. The research was provoked by the need for a relevant comparison between airborne and ground sensors for vegetation analysis and monitoring. The research team used an eBee fixed-wing platform and the multiSPEC 4c and Sequoia sensors. The authors carried out field measurements using a handheld spectrometer by Trimble—GreenSeeker. There were two flight campaigns which took place near the village of Tuhan in the Czech Republic. The results from the first campaign were discouraging, showing less possibility in the correlation between the aerial and field data. The second campaign resulted in a very high percentage of correlation between both types of data. The researchers present the image processing steps and their enhanced photogrammetric workflow for multitemporal data which helps experts and nonprofessionals to reduce their processing time. [ABSTRACT FROM AUTHOR]

Plants are our source of oxygen and nutrients on earth. Therefore, conservation of biodiversity is vital for the survival of other species. With the developing technology, plant species can be examined more closely. Image processing, which is a subject of computer science, has an important role in this field. In this study, an image processing–based method has been developed to automatically separate the petiole region of the plant leaves. To determine the boundary line of the petiole region, the cumulative pixel distributions of the input images in binary format according to the X - and Y -axis are analyzed. Accordingly, optimum thresholds and petiole boundary points are determined. The proposed method was tested on 795 leaf images from 90 different plant species that grow both as trees and shrubs in the Czech Republic. According to the results obtained in experimental studies, it is thought that the proposed method will make an important contribution especially in studies such as automatic classification of plants and leaves and determination of plant species in botanical science. [ABSTRACT FROM AUTHOR]

This paper describes the process of very high-resolution thermal mosaic acquisition using low-altitude airborne remote sensing and the basic analysis of data regarding urban climate research. The process of data acquisition from flight planning to final mosaicking is described. A broadband thermal camera was mounted to a Cessna aeroplane for two flights over the city; one performed in the morning and one in the afternoon. The ground resolution of the final mosaic fluctuates between 90 and 105 cm. Gathered data had to be processed to acquire kinetic temperature values. The processing consisted of radiometric, geometric, atmospheric and emissivity corrections. As a result, two mosaics covering the city were created. The difference between the building canopy layer and ground level was investigated, and a 5°C increase was found during the day on the rooftop level. It was confirmed that natural materials do not heat as much as artificial ones. Local Climate Zones were used in the analysis as the spatial unit for comparison of the thermal regime at the neighbourhood level. To summarise, the possibilities of extreme resolution thermal remote sensing data acquisition and analysis are demonstrated. [ABSTRACT FROM AUTHOR]