scholarly journals Some Dynamic Aspects of Photogrammetry Missions Performed by “PW-ZOOM” – The UAV of Warsaw University of Technology

2017 ◽  
Vol 64 (1) ◽  
pp. 37-55 ◽  
Author(s):  
Mirosław Rodzewicz ◽  
Dominik Głowacki ◽  
Jarosław Hajduk

Abstract The article presents the analyses of the flights carried out the by the Unmanned Aerial Vehicle (UAV) named PW-ZOOM used to perform a photogrammetric mission and monitoring of fauna in Antarctic areas. The analyses focus on the deviations of the optical axis of the photo-camera which occurred during photogrammetric flights carried out on the same route but during several Antarctic expeditions performed in subsequent years (2014 and 2015). The results were subjected to correlation tests with weather conditions (wind speed and variability). The basis for these analyses are the data from the onboard signal recorder integrated with an autopilot.

2019 ◽  
Vol 62 (6) ◽  
pp. 1447-1453 ◽  
Author(s):  
Brian Richardson ◽  
Carol A. Rolando ◽  
Mark O. Kimberley ◽  
Tara M. Strand

HighlightsThe swath pattern was measured from an Agras MG-1 UAV spraying fine and extra-coarse droplet spectra.The recommended lane separation of 3.6 m did not differ for the two droplet size classes tested in this study.The applied spray deposited within the swath was higher with extra-coarse (>90%) than with fine (73%) droplets.There was potential for substantial downwind drift with fine droplets, even when flying close to the ground at low speed.Abstract. While there is increasing interest in the use of small, multi-rotor UAVs for application of agrichemicals, there is also uncertainty about their performance. Consequently, the purpose of this study was to quantify the performance of an Agras MG-1 with modified nozzle positions that, at the time of writing, was being used for commercial spraying in New Zealand. The approach was to release spray from the UAV along a single 50 m line. Spray deposits were measured using horizontal collectors placed on the ground in three 15 m transects centered on, and perpendicular to, the flight line. Airborne deposits were measured with a 10 m mast that supported spherical samplers at 1 m vertical intervals. Analysis of deposition data was undertaken to quantify factors influencing overall swath pattern variability, lane separation associated with a coefficient of variation (CV) of deposition of 30%, and spray application efficiency, which is the proportion of applied spray deposited within the swath. For two droplet size classes (extra-coarse and fine), the lane separation associated with a CV of 30% was about 3.6 m, with no significant effect of droplet size. This is a surprising result and may reflect the relatively small range of environmental conditions experienced during the field tests, including wind speed, which was relatively low for all tests. We speculate that this result may also be a consequence of the strong downwash. The swath width was positively correlated with wind speed. Spray efficiency was shown to be high (>90%) for the extra-coarse droplets but dropped significantly (73%) with the fine droplet spectrum. Combining in-swath deposition with the amount of airborne spray sampled in a 10 m vertical profile close to the edge of the swath accounted for 98.0% of the spray released with the extra-coarse spectrum but only 88.6% of the spray with the fine droplet spectrum. These results highlight that even with UAVs flying relatively close to the ground at a low forward speed, there is potential for substantial drift downwind of the swath when using smaller droplet size classes. Overall, the swath pattern was reasonably consistent across the two droplet size classes and for the narrow range of operational and meteorological conditions tested. Keywords: Aerial spraying, Pesticides, Spray application efficiency, Spray deposition, Swath pattern, UAV, Unmanned aerial vehicle.


Doklady BGUIR ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 65-73
Author(s):  
A. D. Puzanau ◽  
D. S. Nefedov

 The algorithm of detection of acoustic noise provided by an unmanned aerial vehicle (UAV) in the noise background due to wind is synthesized in the article. Creation of the algorithm has been carried out using the Neyman – Pearson lemma. The algorithm assumes a combination of the stages of wind noise coherent compensation and coherent accumulation of UAV’s acoustic noise sound pressure impulses. The coherent accumulation time matches doubled time of fluctuation correlation resulted by experimental research of acoustic noise of different types of  UAVs. Efficiency of the developed algorithm of UAV detection depends on flight velocity, foreshortening, amount of blades and rotor turnovers of UAV as well as weather conditions. For the probability of a false alarm value of 10–4, the probability of correct UAV detection value of 0.9 is provided wherein signal-to-noise ratio has a value of 8 dB. These indicators correspond the detection range of 200 to 300 meters. The obtained results allow discussions about perspective of acoustic UAVs detection systems adaptation. 


2021 ◽  
Vol 12 (1) ◽  
pp. 184
Author(s):  
Ming Zhao ◽  
Zhiyuan Fang ◽  
Hao Yang ◽  
Liangliang Cheng ◽  
Jianfeng Chen ◽  
...  

A method to calibrate the overlap factor of Lidar is proposed, named unmanned aerial vehicle correction (UAVC), which uses unmanned aerial vehicles (UAVs) to detect the vertical distribution of particle concentrations. The conversion relationship between the particulate matter concentration and the aerosol extinction coefficient is inverted by the high-altitude coincidence of the vertical detection profiles of the UAV and Lidar. Using this conversion relationship, the Lidar signal without the influence of the overlap factor can be inverted. Then, the overlap factor profile is obtained by comparing the signal with the original Lidar signal. A 355 nm Raman-Mie Lidar and UAV were used to measure overlap factors under different weather conditions. After comparison with the Raman method, it is found that the overlap factors calculated by the two methods are in good agreement. The changing trend of the extinction coefficient at each height is relatively consistent, after comparing the inversion result of the corrected Lidar signal with the ground data. The results show that after the continuously measured Lidar signal is corrected by the overlap factor measured by this method, low-altitude aerosol information can be effectively obtained.


2020 ◽  
Vol 67 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Rashid K. Kurbanov ◽  
Olga M. Zakharova

The current level of technical development and accessibility allows to consider unmanned aerial vehicles as a reliable tool for operational monitoring of agricultural territories. Drones are able to observe territories that are inaccessible to helicopters and small aircrafts. The use of drones is associated with certain risks that affect flight safety. (Research purpose) To make recommendations on the preflight preparation of unmanned aerial vehicles. (Materials and methods) The authors used scientific literature, survey materials of domestic and foreign authors, websites of UAV manufacturers. (Results and discussion) The authors examined the issues of a drone registration, key parameters that influence data collection and ensure safe monitoring: operation and storage of drone batteries, visual inspection of a drone, sensors calibration, setting the “return home” point and checking the signal GPS/GLONASS communication quality, test flight, restricted areas and weather conditions. (Conclusions) It was established that UAV pre-flight preparation was an important stage in monitoring agricultural fields, which included a number of operations that were carried out with the aim of ensuring the safety of the operator and the unmanned aerial vehicle, as well as to obtain high-quality aerial photography materials. The authors determined that an unmanned aerial vehicle weighing from 250 grams to 30 kilograms was a object to be registered. They identified the need for specialized software, compliance with the rules of operation and storage of batteries, a thorough visual inspection of the drone, calibration of the compass; checking the setting of the return point to the beginning of the route, the GPS/GLONASS signal level, conducting a test flight, monitoring the readings of the inertial measuring unit and weather conditions, checking the zone of prohibited flights.


Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1930
Author(s):  
Eun-Ju Kim ◽  
Sook-Hyun Nam ◽  
Jae-Wuk Koo ◽  
Tae-Mun Hwang

The purpose of this study is to compare the spectral indices for a two-dimensional river algae map using an unmanned aerial vehicle (UAV) and an unmanned surface vehicle (USV) hybrid system. The UAV and USV hybrid systems can overcome the limitation of not being able to effectively compare images of the same region obtained at different times and under different seasonal conditions, when using a method of comparing and analyzing with absolute values in remote sensing. Radiometric correction was performed to minimize the interference that could distort the analysis results of the UAV imagery, and the images were taken under weather conditions that would minimally affect them. Three spectral indices, namely, normalized difference vegetation index (NDVI), normalized green–red difference index (NGRDI), green normalized difference vegetation index (GNDVI), and normalized difference red edge index (NDRE) were compared for the chlorophyll-a images. In field application and correlational analysis, the NDVI was strongly correlated with chlorophyll-a (R2 = 0.88, p < 0.001), and the GNDVI was moderately correlated with chlorophyll-a (R2 = 0.74, p < 0.001). As a result of comparing the chlorophyll-a concentration with the in-situ chlorophyll-a imagery by UAV, we obtained the RMSE of NDVI at 2.25, and the RMSE of GNDVI at 3.41.


Atmosphere ◽  
2017 ◽  
Vol 8 (10) ◽  
pp. 195 ◽  
Author(s):  
Brandon Witte ◽  
Robert Singler ◽  
Sean Bailey

This paper describes the components and usage of an unmanned aerial vehicle developed for measuring turbulence in the atmospheric boundary layer. A method of computing the time-dependent wind speed from a moving velocity sensor data is provided. The physical system built to implement this method using a five-hole probe velocity sensor is described along with the approach used to combine data from the different on-board sensors to allow for extraction of the wind speed as a function of time and position. The approach is demonstrated using data from three flights of two unmanned aerial vehicles (UAVs) measuring the lower atmospheric boundary layer during transition from a stable to convective state. Several quantities are presented and show the potential for extracting a range of atmospheric boundary layer statistics.


Drones ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 44
Author(s):  
Yau Hei Chu ◽  
Chun Leung Ho ◽  
Yoon Jo Lee ◽  
Boyang Li

Having an exciting array of applications, the scope of unmanned aerial vehicle (UAV) application could be far wider one if its flight endurance can be prolonged. Solar-powered UAV, promising notable prolongation in flight endurance, is drawing increasing attention in the industries’ recent research and development. This work arose from a Bachelor’s degree capstone project at Hong Kong Polytechnic University. The project aims to modify a 2-metre wingspan remote-controlled (RC) UAV available in the consumer market to be powered by a combination of solar and battery-stored power. The major objective is to greatly increase the flight endurance of the UAV by the power generated from the solar panels. The power system is first designed by selecting the suitable system architecture and then by selecting suitable components related to solar power. The flight control system is configured to conduct flight tests and validate the power system performance. Under fair experimental conditions with desirable weather conditions, the solar power system on the aircraft results in 22.5% savings in the use of battery-stored capacity. The decrease rate of battery voltage during the stable level flight of the solar-powered UAV built is also much slower than the same configuration without a solar-power system.


Author(s):  
J. B. Babaan ◽  
J. P. Ballori ◽  
A. M. Tamondong ◽  
R. V. Ramos ◽  
P. M. Ostrea

<p><strong>Abstract.</strong> As the unmanned aerial vehicle (UAV) technology has gained popularity over the years, it has been introduced for air quality monitoring. This study demonstrates the feasibility of customized UAV with mobile monitoring devices as an effective, flexible, and alternative means to collect three-dimensional air pollutant concentration data. This also shows the vertical distribution of PM concentration and the relationship between the PM<sub>2.5</sub> vertical distribution and the meteorological parameters within 500<span class="thinspace"></span>m altitude on a single flight in UP Diliman, Quezon City. Measurement and mapping of the vertical distribution of particulate matter (PM)<sub>2.5</sub> concentration is demonstrated in this research using integrated air quality sensors and customized Unmanned Aerial Vehicle. The flight covers an area with a radius of 80 meters, following a cylindrical path with 40-meter interval vertically. The PM<sub>2.5</sub> concentration values are analyzed relative to the meteorological parameters including air speed, pressure, temperature, and relative humidity up to a 500<span class="thinspace"></span>meter-flying height in a single flight in Barangay UP Campus, UP Diliman, Quezon City. The study shows that generally, the PM<sub>2.5</sub> concentration decreases as the height increases with an exception in the 200&amp;ndash;280<span class="thinspace"></span>m above ground height interval due to a sudden change of atmospheric conditions at the time of the flight. Using correlation and regression analysis, the statistics shows that PM<sub>2.5</sub> concentration has a positive relationship with temperature and a negative relationship with relative humidity and wind speed. As relative humidity and wind speed increases, PM<sub>2.5</sub> decreases, while as temperature increases, PM<sub>2.5</sub> also increases.</p>


2020 ◽  
Vol 1 (1) ◽  
pp. 34-41
Author(s):  
S Mosov ◽  
V Neroba ◽  
O Sieliukov

The article identifies the conditions and factors that will affect the operation of unmanned aerial vehicles during its use in emergencies. The purpose of the study is to systematize the conditions and factors that will affect the functioning of specific technical means of surveillance installed on the unmanned aerial vehicle. The study of conditions and factors was carried out with a preliminary determination of the general indicators of efficiency of specific technical means of observation installed on the drone, which include: the probability of detection and recognition of the object by the operator (pilot-operator) on the display screen; the scale of the image on the display screen; viewing angle of the species technical means of observation; transverse capture of the area during aerial surveillance with the help of specific technical means; spectral range of operation of the species technical means of observation and the height of observation. According to the results of research, the conditions and factors include: unmanned aerial vehicle; set task for observation (monitoring); terrain features; control by the pilot (pilot-operator); weather conditions; gusts of wind; season; time of day; drone vibrations during flight; atmospheric turbulence; control of specific technical means of observation by the operator (pilot-operator); temperature regime; the presence of a library of signatures of the object of observation. It is concluded that the results of the study of conditions and factors that will affect the use of specific technical means of observation installed on an unmanned aerial vehicle are the basis for developing relevant requirements for specific technical means of observation of visible and infrared wavelengths of the electromagnetic spectrum. Further research should be carried out in the following areas: development or purchase of unmanned aerial vehicles for observation during the prevention and elimination of emergencies; development of libraries of signatures of objects of observation; research of possibilities of application of spectrozonal or multispectral species equipment for observation; creation of special training grounds for training and retraining of pilots and operators of unmanned aerial vehicles, etc.


2020 ◽  
pp. paper82-1-paper82-10
Author(s):  
Mainak Mondal ◽  
Stanislav Shidlovskiy ◽  
Dmitriy Shashev

This article describes the use of a monocular camera attached to a multirotor perpendicular to the horizon, to recognize visual cues or artefacts (AprilTag) and use it as an anchor for aerial alignment to finally land on it, thus attempting to make autonomous flights safer and usable in slightly hard-to-reach locations. A Hexacopter frame with the DJI N3 flight controller was used for prototyping and realizing the desired algorithm. Factors like wind speed and gusts were taken into account as well as the center of gravity of the multirotor and the position of the molecular camera attached to the copter facing downwards or at a 90-degree angle. The results of the experiments conducted were verified against existing methods like the GPS (Global Positioning System) waypoint mission provided by major commercial Unmanned Aerial Vehicle(UAV) or Flight Controller manufacturers and were also compared to experimental methods presented in related research articles, fairing excellent results


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