scholarly journals Integration of Radiometric Ground-Based Data and High-Resolution QuickBird Imagery with Multivariate Modeling to Estimate Maize Traits in the Nile Delta of Egypt

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3915
Author(s):  
Adel H. Elmetwalli ◽  
Andrew N. Tyler ◽  
Farahat S. Moghanm ◽  
Saad A.M. Alamri ◽  
Ebrahem M. Eid ◽  
...  

In site-specific management, rapid and accurate identification of crop stress at a large scale is critical. Radiometric ground-based data and satellite imaging with advanced spatial and spectral resolution allow for a deeper understanding of crop stress and the level of stress in a given area. This research aimed to assess the potential of radiometric ground-based data and high-resolution QuickBird satellite imagery to determine the leaf area index (LAI), biomass fresh weight (BFW) and chlorophyll meter (Chlm) of maize across well-irrigated, water stress and salinity stress areas in the Nile Delta of Egypt. Partial least squares regression (PLSR) and multiple linear regression (MLR) were evaluated to estimate the three measured traits based on vegetation spectral indices (vegetation-SRIs) derived from these methods and their combination. Maize field visits were conducted during the summer seasons from 28 to 30 July 2007 to collect ground reference data concurrent with the acquisition of radiometric ground-based measurements and QuickBird satellite imagery. The results showed that the majority of vegetation-SRIs extracted from radiometric ground-based data and high-resolution satellite images were more effective in estimating LAI, BFW, and Chlm. In general, the vegetation-SRIs of radiometric ground-based data showed higher R2 with measured traits compared to the vegetation-SRIs extracted from high-resolution satellite imagery. The coefficient of determination (R2) of the significant relationships between vegetation-SRIs of both methods and three measured traits varied from 0.64 to 0.89. For example, with QuickBird high-resolution satellite images, the relationships of the green normalized difference vegetation index (GNDVI) with LAI and BFW showed the highest R2 of 0.80 and 0.84, respectively. Overall, the ground-based vegetation-SRIs and the satellite-based indices were found to be in good agreement to assess the measured traits of maize. Both the calibration (Cal.) and validation (Val.) models of PLSR and MLR showed the highest performance in predicting the three measured traits based on the combination of vegetation-SRIs from radiometric ground-based data and high-resolution QuickBird satellite imagery. For example, validation (Val.) models of PLSR and MLR showed the highest performance in predicting the measured traits based on the combination of vegetation-SRIs from radiometric ground-based data and high-resolution QuickBird satellite imagery with R2 (0.91) of both methods for LAI, R2 (0.91–0.93) for BFW respectively, and R2 (0.82) of both methods for Chlm. The models of PLSR and MLR showed approximately the same performance in predicting the three measured traits and no clear difference was found between them and their combinations. In conclusion, the results obtained from this study showed that radiometric ground-based measurements and high spectral resolution remote-sensing imagery have the potential to offer necessary crop monitoring information across well-irrigated, water stress and salinity stress in regions suffering lack of freshwater resources.

Author(s):  
L. Abraham ◽  
M. Sasikumar

In the past decades satellite imagery has been used successfully for weather forecasting, geographical and geological applications. Low resolution satellite images are sufficient for these sorts of applications. But the technological developments in the field of satellite imaging provide high resolution sensors which expands its field of application. Thus the High Resolution Satellite Imagery (HRSI) proved to be a suitable alternative to aerial photogrammetric data to provide a new data source for object detection. Since the traffic rates in developing countries are enormously increasing, vehicle detection from satellite data will be a better choice for automating such systems. In this work, a novel technique for vehicle detection from the images obtained from high resolution sensors is proposed. Though we are using high resolution images, vehicles are seen only as tiny spots, difficult to distinguish from the background. But we are able to obtain a detection rate not less than 0.9. Thereafter we classify the detected vehicles into cars and trucks and find the count of them.


2019 ◽  
Vol 14 (31) ◽  
pp. 81-88
Author(s):  
Anaam Kadhim Hadi

This research presents a new algorithm for classification theshadow and water bodies for high-resolution satellite images (4-meter) of Baghdad city, have been modulated the equations of thecolor space components C1-C2-C3. Have been using the color spacecomponent C3 (blue) for discriminating the shadow, and has beenused C1 (red) to detect the water bodies (river). The new techniquewas successfully tested on many images of the Google earth andIkonos. Experimental results show that this algorithm effective todetect all the types of the shadows with color, and also detects thewater bodies in another color. The benefit of this new technique todiscriminate between the shadows and water in fast Matlab program.


Author(s):  
Niharika Goswami ◽  
Keyurkumar Kathiriya ◽  
Santosh Yadav ◽  
Janki Bhatt ◽  
Sheshang Degadwala

Object detection from satellite images has been a challenging problem for many years. With the development of effective deep learning algorithms and advancement in hardware systems, higher accuracies have been achieved in the detection of various objects from very high-resolution satellite images. In the past decades satellite imagery has been used successfully for weather forecasting, geographical and geological applications. Low resolution satellite images are sufficient for these sorts of applications. But the technological developments in the field of satellite imaging provide high resolution sensors which expands its field of application. Thus, the High-Resolution Satellite Imagery (HRSI) proved to be a suitable alternative to aerial photogrammetric data to provide a new data source for object detection. Since the traffic rates in developing countries are enormously increasing, vehicle detection from satellite data will be a better choice for automating such systems. In this research, a different technique for vehicle detection from the images obtained from high resolution sensors is reviewed. This review presents the recent progress in the field of object detection from satellite imagery using deep learning.


2011 ◽  
Vol 42 ◽  
pp. 103-116 ◽  
Author(s):  
Martin Sterry ◽  
David Mattingly ◽  
Muftah Ahmed ◽  
Toby Savage ◽  
Kevin White ◽  
...  

AbstractReconnaissance survey in the Murzuq area, some 150 km south-east of Jarma, was carried out as part of the 2011 field programme of the Desert Migrations Project, with separate funding from the Leverhulme Trust for this element of work entitled the ‘Peopling the Desert Project’. This survey was designed to provide field verification of details of settlement systems identified and mapped from high-resolution satellite images in an area of c. 600 km2 immediately east of the oasis town of Murzuq. Examination of high-resolution QuickBird and Ikonos satellite imagery has permitted identification of a large dossier of more than 200 sites (fortified buildings known as qsur, other settlements, cemeteries, wells, fields/gardens and linear irrigation works called foggaras). The majority of these sites have never been previously noted or mapped and the date of the sites was unknown at the outset, though they clearly pertained to the historic periods. While further study of the finds and scientific dating evidence is required, the initial results of the brief field visit have major implications for our understanding of Garamantian and early Islamic settlement in south-eastern Fazzan.


2019 ◽  
Vol 11 (12) ◽  
pp. 1422 ◽  
Author(s):  
Wei Li ◽  
Jiale Jiang ◽  
Tai Guo ◽  
Meng Zhou ◽  
Yining Tang ◽  
...  

High-resolution satellite images can be used to some extent to mitigate the mixed-pixel problem caused by the lack of intensive production, farmland fragmentation, and the uneven growth of field crops in developing countries. Specifically, red-edge (RE) satellite images can be used in this context to reduce the influence of soil background at early stages as well as saturation due to crop leaf area index (LAI) at later stages. However, the availability of high-resolution RE satellite image products for research and application globally remains limited. This study uses the weight-and-unmixing algorithm as well as the SUPer-REsolution for multi-spectral Multi-resolution Estimation (Wu-SupReME) approach to combine the advantages of Sentinel-2 spectral and Planet spatial resolution and generate a high-resolution RE product. The resultant fused image is highly correlated (R2 > 0.98) with Sentinel-2 image and clearly illustrates the persistent advantages of such products. This fused image was significantly more accurate than the originals when used to predict heterogeneous wheat LAI and therefore clearly illustrated the persistence of Sentinel-2 spectral and Planet spatial advantage, which indirectly proved that the fusion methodology of generating high-resolution red-edge products from Planet and Sentinel-2 images is possible. This study provided method reference for multi-source data fusion and image product for accurate parameter inversion in quantitative remote sensing of vegetation.


2021 ◽  
pp. 1-11
Author(s):  
Yasser Mostafa ◽  
Mahmoud Nokrashy O. Ali ◽  
Faten Mostafa ◽  
Mohamed Yousef

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