Research professional of GIS and Remote Sensing with expertise in using UAV for precision agriculture Phone: +4550361347 Address: University of Copenhagen Faculty of Science Department of Plant and Environmental Sciences (PLEN), Section of Crop Sciences, Plant Protection Group Højbakkegård Alle 9, 2630 Taastrup, Denmark.
Land surface temperature is an estimate of ground temperature and the important to identify chang... more Land surface temperature is an estimate of ground temperature and the important to identify changes in environment. Many researchers have estimated it by measuring the air temperature, using land based observation stations, equipments and related weather data which are both expensive and time consuming. It also leads to problems in spatial analysis. But now days, remote sensing is the best alternative. The advantages of using remotely sensed data are the availability, consistent and repetitive coverage and capability of measurements of earth surface environment. There are many satellites with available data which can be used for estimating land surface temperature. Among them Landsat is the most popular one. But estimating land surface temperature from Landsat thermal imagery consists of several complex steps which can be simplified through by modeling. The aim of this research is to prepare a model for estimating land surface temperature in New Delhi and its surrounding from Landsat Thermal Imagery. Landsat 5 TM data of October 01, 2011 and Landsat 7 ETM+ data of October 08, 2000 are used to make the modeling applicable for various Landsat data. Emissivity was retrieved from satellite data by using Normalized Difference Vegetation Index (NDVI) and used in modeling to ensure least error. Modeling was accomplished in ERDAS EMAGINE. Result of the research showed the structures of model. It also showed the spatial variation of land surface temperature. Comparisons showed how precise estimated land surface temperature was in respect to some land observation data.
On/off patch spraying requires two prerequisites for realizing patch spraying as accurate weed de... more On/off patch spraying requires two prerequisites for realizing patch spraying as accurate weed detection and targeting of the herbicides on weed patches. This study assessed the extent to which patch-sprayed herbicides are targeted precisely according to pre-loaded prescription maps and evaluated a new method of spatial accuracy which consisted of spraying with red Ponceau 4R dye, unmanned aerial vehicle (UAV) imagery and GIS based spatial image analysis. The sprayed dye was clearly visible in areal images and the locations of the sprayed areas were compared with the locations given by the prescription maps. Four different commercial sprayers with boom section width in the range of 0.5 to 3 m and driving speed in the range of 2.5 to 8 km h-1 were used in ten experiments. All the experiments were carried out in autumn in stubble fields. The results showed that the new method was fast and reliable. The incorrectly sprayed area outside targeted areas on prescription maps averaged 81% for three different sprayers with 3 m boom sections, and 5% for a sprayer with 0.5 m boom sections (individual spray nozzle control). The target areas not sprayed within the planned weed patch areas averaged 6% of the pre-defined patch area for sprayers with 3 m boom sections, and 14% for the sprayer with 0.5 m boom sections. This study also revealed that the sprayer with 0.5 m boom sections had a controller that was not quick enough at opening and closing spray nozzles at normal driving speeds. It also observed that Log files from the sprayer console overestimated the sprayed area by 24 % and were less accurate than the spatial analysis of the sprayed areas.
This study shows that QGIS geo-rectification offers a practical alternative to enhance spatial ac... more This study shows that QGIS geo-rectification offers a practical alternative to enhance spatial accuracy and to resolve spatial distortion. It reduced spatial error up to 87% with average RMSE of 1.42 m using google earth image and 93% with RMSE 0f 0.73 m using A-B lines. A-B lines is more efficient than Google Earth images in geo-rectification using QGIS. ANOVA showed that flight altitude and photogrammetry software had no impact on the spatial accuracy. The largest field resulted in a greater accuracy than the smaller one CONCLUSIONS Geo-rectification in QGIS offers a viable alternative to the use of costly methods to achieve high spatial accuracy producing RMSEs from less than 1 m to up to 1.4 m and still within the range relevant for precision agriculture applications upon user's choice.
Urban growth is the most evident aspect of anthropogenic impact on the earth system, replacing th... more Urban growth is the most evident aspect of anthropogenic impact on the earth system, replacing the natural physical characteristics of earth’s surface and thus influencing the thermal environment. The resulting thermal environment impact is especially observed in developing countries like Bangladesh. In this study, we assess, evaluate, and explore the growth of urban areas over Bangladesh for summer and winter seasons of 2003–2013 using Landsat-7 ETM+. We integrate the expected urban growth scenarios with the thermal environment through demographic, environmental, and physical datasets and also predict urban growth. We delineated urban areas over Bangladesh using Impervious Surface Area (ISA) with 90% accuracy and observed a 128% increase in urban areas during the 10 years. We used multivariate technique with satellite-derived land surface temperature, Surface Urban Heat Island Intensity (SUHII), Albedo and artificial heat flux in identifying the urban hotspots in various cities ove...
Bangladesh is an agriculture-dependent country and very often this sector struggles a lot due to ... more Bangladesh is an agriculture-dependent country and very often this sector struggles a lot due to various natural hazards including drought and flood. Almost every year in kharif crop season, Bangladesh undergoes through drought which causes a lot of yield loss. So, this has become important to identify the drought-prone areas to reduce the risk of crops yield loss and for policymaking to suggest alternative drought-tolerant crops. The agricultural drought is related to soil properties because of having spatially dynamic in nature. In the present study, agricultural drought has been assessed comprising meteorological drought of kharif season and water holding capacity (WHC) in Geographic Information System (GIS) platform, as GIS is a widely used as a powerful tool to manage and model the spatial data. The metrological drought map has prepared by rainfall data with the calculation of Standardized Precipitation Index (SPI) using GIS and WHC of soil map has converted from soil texture m...
Site-specific weed management (SSWM) may reduce herbicide use by identifying weed patches and wee... more Site-specific weed management (SSWM) may reduce herbicide use by identifying weed patches and weed-free areas. However, one major constraint is robust weed detection algorithms that are able to predict weed infestations outside of the training data. This study investigates the predictive power of regression models trained on drone imagery that are used within fields to predict infestations of annual grass weeds in the late growth stages of cereals. The main objective was to identify the optimum sampling strategy for training regression models based on aerial RGB images. The study showed that training based on sampling from the whole range of weed infestations or the extreme values in the field provided better prediction accuracy than random sampling. Prediction models based on vegetation indices (VIs) offered a useful alternative to a more complex random forest machine-learning algorithm. For binary decision-making, linear regression utilizing weed density information resulted in hi...
On/off patch spraying based on weed maps is used in site-specific weed management. Two prerequisi... more On/off patch spraying based on weed maps is used in site-specific weed management. Two prerequisites for realising patch spraying are accurate weed detection and targeting of the herbicides on weed patches. There is plenty in the literature about weed detection, but little attention has been paid to the spatial accuracy of herbicide application. This study was conducted in order to assess the extent to which patch-sprayed herbicides are targeted precisely according to pre-loaded prescription maps and to evaluate a new spatial assessment method. The new method consisted of spraying with red Ponceau 4R dye, unmanned aerial vehicle (UAV) imagery and spatial image analysis based on a geographic information system (GIS). The sprayed dye was clearly visible in aereal images and the locations of the sprayed areas were compared with the locations given by the prescription maps. Four different commercial sprayers with boom section width in the range of 0.5 to 3 m and driving speed in the range of 2.5 to 8 km h −1 were used in ten experiments. All the experiments were carried out in autumn in stubble fields. The results showed that the new method was fast and reliable. The incorrectly sprayed area outside targeted areas on prescription maps averaged 81% for three different sprayers with 3 m boom sections, and 5% for a sprayer with 0.5 m boom sections (individual spray nozzle control). The target areas not sprayed within the planned weed patch areas averaged 6% of the pre-defined patch area for spray-ers with 3 m boom sections, and 14% for the sprayer with 0.5 m boom sections. This study revealed that the sprayer with 0.5 m boom sections had a controller that was not quick enough at opening and closing spray nozzles at normal driving speeds. Log files from the sprayer console overestimated the sprayed area by 24% and were less accurate than the spatial analysis of the sprayed areas.
9th Advanced Training Course on Land Remote Sensing with the focus on Agriculture, 2019
On/off patch spraying requires two prerequisites for realizing patch spraying as accurate weed de... more On/off patch spraying requires two prerequisites for realizing patch spraying as accurate weed detection and targeting of the herbicides on weed patches. This study assessed the extent to which patch-sprayed herbicides are targeted precisely according to pre-loaded prescription maps and evaluated a new method of spatial accuracy which consisted of spraying with red Ponceau 4R dye, unmanned aerial vehicle (UAV) imagery and GIS based spatial image analysis. The sprayed dye was clearly visible in areal images and the locations of the sprayed areas were compared with the locations given by the prescription maps. Four different commercial sprayers with boom section width in the range of 0.5 to 3 m and driving speed in the range of 2.5 to 8 km h-1 were used in ten experiments. All the experiments were carried out in autumn in stubble fields. The results showed that the new method was fast and reliable. The incorrectly sprayed area outside targeted areas on prescription maps averaged 81% for three different sprayers with 3 m boom sections, and 5% for a sprayer with 0.5 m boom sections (individual spray nozzle control). The target areas not sprayed within the planned weed patch areas averaged 6% of the pre-defined patch area for sprayers with 3 m boom sections, and 14% for the sprayer with 0.5 m boom sections. This study also revealed that the sprayer with 0.5 m boom sections had a controller that was not quick enough at opening and closing spray nozzles at normal driving speeds. It also observed that Log files from the sprayer console overestimated the sprayed area by 24 % and were less accurate than the spatial analysis of the sprayed areas.
The global spatial accuracy of ortho-mosaics based on images from consumer-grade unmanned aerial ... more The global spatial accuracy of ortho-mosaics based on images from consumer-grade unmanned aerial vehicles (UAVs) is relatively low. The use of ground control points (GCPs) improves the accuracy but it requires RTK-GNSS (global navigation satellite system) measurements in the field. The objective of this study was to evaluate manual geo-rec-tification after ortho-mosaicking as a cost-effective alternative to GCPs or UAVs equipped with RTK-GNSS. Google Earth images and A-B lines used for tractor auto-steering were used for manual geo-rectification with a free geographic information system (GIS) and remote-sensing (RS) software (QGIS). Two different photogrammetry software (Agisoft Photoscan and Pix4DMapper) were used for ortho-mosaicking. Images were captured in three fields at two altitudes (40 and 80 m) with a multi-rotor camera drone equipped with a GNSS without ground reference (Phantom 4). The results showed that flight altitude and photogrammetry software had no impact on the spatial accuracy and that manual geo-recti-fication significantly improved the spatial accuracy. Root mean squares (RMSEs) for ortho-mosaics without geo-rectification was in the range of 4 to 28 m and the range was 0.6 to 2.5 m and 0.5 to 1.1 m for geo-rectification based on Google Earth images and A-B-lines, respectively. RTK-GNSS tagged UAV images and the use of GCPs gave average RMSEs of less than 0.1 m. It was concluded that manual geo-rectification offers a feasible alternative to GCPs and UAVs with RTK-GNSS when spatial accuracy of about 1 m is acceptable.
Land surface temperature is an estimate of ground temperature and the important to identify chang... more Land surface temperature is an estimate of ground temperature and the important to identify changes in environment. Many researchers have estimated it by measuring the air temperature, using land based observation stations, equipments and related weather data which are both expensive and time consuming. It also leads to problems in spatial analysis. But now days, remote sensing is the best alternative. The advantages of using remotely sensed data are the availability, consistent and repetitive coverage and capability of measurements of earth surface environment. There are many satellites with available data which can be used for estimating land surface temperature. Among them Landsat is the most popular one. But estimating land surface temperature from Landsat thermal imagery consists of several complex steps which can be simplified through by modeling. The aim of this research is to prepare a model for estimating land surface temperature in New Delhi and its surrounding from Landsat Thermal Imagery. Landsat 5 TM data of October 01, 2011 and Landsat 7 ETM+ data of October 08, 2000 are used to make the modeling applicable for various Landsat data. Emissivity was retrieved from satellite data by using Normalized Difference Vegetation Index (NDVI) and used in modeling to ensure least error. Modeling was accomplished in ERDAS EMAGINE. Result of the research showed the structures of model. It also showed the spatial variation of land surface temperature. Comparisons showed how precise estimated land surface temperature was in respect to some land observation data.
On/off patch spraying requires two prerequisites for realizing patch spraying as accurate weed de... more On/off patch spraying requires two prerequisites for realizing patch spraying as accurate weed detection and targeting of the herbicides on weed patches. This study assessed the extent to which patch-sprayed herbicides are targeted precisely according to pre-loaded prescription maps and evaluated a new method of spatial accuracy which consisted of spraying with red Ponceau 4R dye, unmanned aerial vehicle (UAV) imagery and GIS based spatial image analysis. The sprayed dye was clearly visible in areal images and the locations of the sprayed areas were compared with the locations given by the prescription maps. Four different commercial sprayers with boom section width in the range of 0.5 to 3 m and driving speed in the range of 2.5 to 8 km h-1 were used in ten experiments. All the experiments were carried out in autumn in stubble fields. The results showed that the new method was fast and reliable. The incorrectly sprayed area outside targeted areas on prescription maps averaged 81% for three different sprayers with 3 m boom sections, and 5% for a sprayer with 0.5 m boom sections (individual spray nozzle control). The target areas not sprayed within the planned weed patch areas averaged 6% of the pre-defined patch area for sprayers with 3 m boom sections, and 14% for the sprayer with 0.5 m boom sections. This study also revealed that the sprayer with 0.5 m boom sections had a controller that was not quick enough at opening and closing spray nozzles at normal driving speeds. It also observed that Log files from the sprayer console overestimated the sprayed area by 24 % and were less accurate than the spatial analysis of the sprayed areas.
This study shows that QGIS geo-rectification offers a practical alternative to enhance spatial ac... more This study shows that QGIS geo-rectification offers a practical alternative to enhance spatial accuracy and to resolve spatial distortion. It reduced spatial error up to 87% with average RMSE of 1.42 m using google earth image and 93% with RMSE 0f 0.73 m using A-B lines. A-B lines is more efficient than Google Earth images in geo-rectification using QGIS. ANOVA showed that flight altitude and photogrammetry software had no impact on the spatial accuracy. The largest field resulted in a greater accuracy than the smaller one CONCLUSIONS Geo-rectification in QGIS offers a viable alternative to the use of costly methods to achieve high spatial accuracy producing RMSEs from less than 1 m to up to 1.4 m and still within the range relevant for precision agriculture applications upon user's choice.
Urban growth is the most evident aspect of anthropogenic impact on the earth system, replacing th... more Urban growth is the most evident aspect of anthropogenic impact on the earth system, replacing the natural physical characteristics of earth’s surface and thus influencing the thermal environment. The resulting thermal environment impact is especially observed in developing countries like Bangladesh. In this study, we assess, evaluate, and explore the growth of urban areas over Bangladesh for summer and winter seasons of 2003–2013 using Landsat-7 ETM+. We integrate the expected urban growth scenarios with the thermal environment through demographic, environmental, and physical datasets and also predict urban growth. We delineated urban areas over Bangladesh using Impervious Surface Area (ISA) with 90% accuracy and observed a 128% increase in urban areas during the 10 years. We used multivariate technique with satellite-derived land surface temperature, Surface Urban Heat Island Intensity (SUHII), Albedo and artificial heat flux in identifying the urban hotspots in various cities ove...
Bangladesh is an agriculture-dependent country and very often this sector struggles a lot due to ... more Bangladesh is an agriculture-dependent country and very often this sector struggles a lot due to various natural hazards including drought and flood. Almost every year in kharif crop season, Bangladesh undergoes through drought which causes a lot of yield loss. So, this has become important to identify the drought-prone areas to reduce the risk of crops yield loss and for policymaking to suggest alternative drought-tolerant crops. The agricultural drought is related to soil properties because of having spatially dynamic in nature. In the present study, agricultural drought has been assessed comprising meteorological drought of kharif season and water holding capacity (WHC) in Geographic Information System (GIS) platform, as GIS is a widely used as a powerful tool to manage and model the spatial data. The metrological drought map has prepared by rainfall data with the calculation of Standardized Precipitation Index (SPI) using GIS and WHC of soil map has converted from soil texture m...
Site-specific weed management (SSWM) may reduce herbicide use by identifying weed patches and wee... more Site-specific weed management (SSWM) may reduce herbicide use by identifying weed patches and weed-free areas. However, one major constraint is robust weed detection algorithms that are able to predict weed infestations outside of the training data. This study investigates the predictive power of regression models trained on drone imagery that are used within fields to predict infestations of annual grass weeds in the late growth stages of cereals. The main objective was to identify the optimum sampling strategy for training regression models based on aerial RGB images. The study showed that training based on sampling from the whole range of weed infestations or the extreme values in the field provided better prediction accuracy than random sampling. Prediction models based on vegetation indices (VIs) offered a useful alternative to a more complex random forest machine-learning algorithm. For binary decision-making, linear regression utilizing weed density information resulted in hi...
On/off patch spraying based on weed maps is used in site-specific weed management. Two prerequisi... more On/off patch spraying based on weed maps is used in site-specific weed management. Two prerequisites for realising patch spraying are accurate weed detection and targeting of the herbicides on weed patches. There is plenty in the literature about weed detection, but little attention has been paid to the spatial accuracy of herbicide application. This study was conducted in order to assess the extent to which patch-sprayed herbicides are targeted precisely according to pre-loaded prescription maps and to evaluate a new spatial assessment method. The new method consisted of spraying with red Ponceau 4R dye, unmanned aerial vehicle (UAV) imagery and spatial image analysis based on a geographic information system (GIS). The sprayed dye was clearly visible in aereal images and the locations of the sprayed areas were compared with the locations given by the prescription maps. Four different commercial sprayers with boom section width in the range of 0.5 to 3 m and driving speed in the range of 2.5 to 8 km h −1 were used in ten experiments. All the experiments were carried out in autumn in stubble fields. The results showed that the new method was fast and reliable. The incorrectly sprayed area outside targeted areas on prescription maps averaged 81% for three different sprayers with 3 m boom sections, and 5% for a sprayer with 0.5 m boom sections (individual spray nozzle control). The target areas not sprayed within the planned weed patch areas averaged 6% of the pre-defined patch area for spray-ers with 3 m boom sections, and 14% for the sprayer with 0.5 m boom sections. This study revealed that the sprayer with 0.5 m boom sections had a controller that was not quick enough at opening and closing spray nozzles at normal driving speeds. Log files from the sprayer console overestimated the sprayed area by 24% and were less accurate than the spatial analysis of the sprayed areas.
9th Advanced Training Course on Land Remote Sensing with the focus on Agriculture, 2019
On/off patch spraying requires two prerequisites for realizing patch spraying as accurate weed de... more On/off patch spraying requires two prerequisites for realizing patch spraying as accurate weed detection and targeting of the herbicides on weed patches. This study assessed the extent to which patch-sprayed herbicides are targeted precisely according to pre-loaded prescription maps and evaluated a new method of spatial accuracy which consisted of spraying with red Ponceau 4R dye, unmanned aerial vehicle (UAV) imagery and GIS based spatial image analysis. The sprayed dye was clearly visible in areal images and the locations of the sprayed areas were compared with the locations given by the prescription maps. Four different commercial sprayers with boom section width in the range of 0.5 to 3 m and driving speed in the range of 2.5 to 8 km h-1 were used in ten experiments. All the experiments were carried out in autumn in stubble fields. The results showed that the new method was fast and reliable. The incorrectly sprayed area outside targeted areas on prescription maps averaged 81% for three different sprayers with 3 m boom sections, and 5% for a sprayer with 0.5 m boom sections (individual spray nozzle control). The target areas not sprayed within the planned weed patch areas averaged 6% of the pre-defined patch area for sprayers with 3 m boom sections, and 14% for the sprayer with 0.5 m boom sections. This study also revealed that the sprayer with 0.5 m boom sections had a controller that was not quick enough at opening and closing spray nozzles at normal driving speeds. It also observed that Log files from the sprayer console overestimated the sprayed area by 24 % and were less accurate than the spatial analysis of the sprayed areas.
The global spatial accuracy of ortho-mosaics based on images from consumer-grade unmanned aerial ... more The global spatial accuracy of ortho-mosaics based on images from consumer-grade unmanned aerial vehicles (UAVs) is relatively low. The use of ground control points (GCPs) improves the accuracy but it requires RTK-GNSS (global navigation satellite system) measurements in the field. The objective of this study was to evaluate manual geo-rec-tification after ortho-mosaicking as a cost-effective alternative to GCPs or UAVs equipped with RTK-GNSS. Google Earth images and A-B lines used for tractor auto-steering were used for manual geo-rectification with a free geographic information system (GIS) and remote-sensing (RS) software (QGIS). Two different photogrammetry software (Agisoft Photoscan and Pix4DMapper) were used for ortho-mosaicking. Images were captured in three fields at two altitudes (40 and 80 m) with a multi-rotor camera drone equipped with a GNSS without ground reference (Phantom 4). The results showed that flight altitude and photogrammetry software had no impact on the spatial accuracy and that manual geo-recti-fication significantly improved the spatial accuracy. Root mean squares (RMSEs) for ortho-mosaics without geo-rectification was in the range of 4 to 28 m and the range was 0.6 to 2.5 m and 0.5 to 1.1 m for geo-rectification based on Google Earth images and A-B-lines, respectively. RTK-GNSS tagged UAV images and the use of GCPs gave average RMSEs of less than 0.1 m. It was concluded that manual geo-rectification offers a feasible alternative to GCPs and UAVs with RTK-GNSS when spatial accuracy of about 1 m is acceptable.
This document is a two days (one hour each day) course on R for Saint Mary's University, Halifax,... more This document is a two days (one hour each day) course on R for Saint Mary's University, Halifax, Canada designed and conducted by myself. Demo data (xlsx format) is also attached herewith.
This is a step to step tutorial to geo-correct a processed UAV image using Google earth satellite... more This is a step to step tutorial to geo-correct a processed UAV image using Google earth satellite image in QGIS. It also includes the re-projection of UAV image in QGIS
Urban growth is the most evident aspect of anthropogenic impact on the earth system, replacing th... more Urban growth is the most evident aspect of anthropogenic impact on the earth system, replacing the natural physical characteristics of earth's surface and thus influencing the thermal environment. The resulting thermal environment impact is especially observed in developing countries like Bangladesh. In this study, we assess, evaluate, and explore the growth of urban areas over Bangladesh for summer and winter seasons of 2003–2013 using Landsat-7 ETM+. We integrate the expected urban growth scenarios with the thermal environment through demographic, environmental, and physical datasets and also predict urban growth. We delineated urban areas over Bangladesh using Impervious Surface Area (ISA) with 90% accuracy and observed a 128% increase in urban areas during the 10 years. We used multivariate technique with satellite-derived land surface temperature, Surface Urban Heat Island Intensity (SUHII), Albedo and artificial heat flux in identifying the urban hotspots in various cities over Bangladesh. The results indicate an increase in urban areas in the first 5 years (2003–2008) by over 100% and in the next 5 years (2008–2013) by 200% mainly due to lack of urban planning policies. Our results indicate an enormous increase of 167% in Urban Heat Island Effect Ratio (UHIER) during the period. We also used advanced statistical analysis to assess the relationship between selected demographic (population), environmental (PM2.5, PM10, relative humidity, and air temperature) and physical parameters (Urbanization Index and Urban Density Cluster) and identified parameters, which are most influencing to the thermal environment. Our results suggest the significant increase in UHIER by 2018 over major cities in Bangladesh. To reduce the influence of urban growth on thermal environment, we recommend mitigation measures useful for urban planners and decision makers to ensure safety and public health in Bangladesh.
Advanced Training Course on Land Remote Sensing with the focus on Agriculture, 2019
On/off patch spraying requires two prerequisites for realizing patch spraying as accurate weed de... more On/off patch spraying requires two prerequisites for realizing patch spraying as accurate weed detection and targeting of the herbicides on weed patches. This study assessed the extent to which patch-sprayed herbicides are targeted precisely according to pre-loaded prescription maps and evaluated a new method of spatial accuracy which consisted of spraying with red Ponceau 4R dye, unmanned aerial vehicle (UAV) imagery and GIS based spatial image analysis. The sprayed dye was clearly visible in areal images and the locations of the sprayed areas were compared with the locations given by the prescription maps. Four different commercial sprayers with boom section width in the range of 0.5 to 3 m and driving speed in the range of 2.5 to 8 km h-1 were used in ten experiments. All the experiments were carried out in autumn in stubble fields. The results showed that the new method was fast and reliable. The incorrectly sprayed area outside targeted areas on prescription maps averaged 81% for three different sprayers with 3 m boom sections, and 5% for a sprayer with 0.5 m boom sections (individual spray nozzle control). The target areas not sprayed within the planned weed patch areas averaged 6% of the pre-defined patch area for sprayers with 3 m boom sections, and 14% for the sprayer with 0.5 m boom sections. This study also revealed that the sprayer with 0.5 m boom sections had a controller that was not quick enough at opening and closing spray nozzles at normal driving speeds. It also observed that Log files from the sprayer console overestimated the sprayed area by 24 % and were less accurate than the spatial analysis of the sprayed areas.
This study shows that QGIS geo-rectification offers a practical alternative to enhance spatial ac... more This study shows that QGIS geo-rectification offers a practical alternative to enhance spatial accuracy and to resolve spatial distortion. It reduced spatial error up to 87% with average RMSE of 1.42 m using google earth image and 93% with RMSE 0f 0.73 m using A-B lines. A-B lines is more efficient than Google Earth images in geo-rectification using QGIS. ANOVA showed that flight altitude and photogrammetry software had no impact on the spatial accuracy. The largest field resulted in a greater accuracy than the smaller one CONCLUSIONS Geo-rectification in QGIS offers a viable alternative to the use of costly methods to achieve high spatial accuracy producing RMSEs from less than 1 m to up to 1.4 m and still within the range relevant for precision agriculture applications upon user's choice.
This is a scratch note to understand danish grammar and to get standard samples for PD-3 speaking... more This is a scratch note to understand danish grammar and to get standard samples for PD-3 speaking and writing test
A note with all important information together in english along with important danish words and t... more A note with all important information together in english along with important danish words and terms from the lecture material for active citizenship test in Denmark (2020)
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