The Potential of Low Altitude Aerial Data for Large Scale Mapping

2014 ◽  
Vol 70 (5) ◽  
Author(s):  
Norhadija Darwin ◽  
Anuar Ahmad ◽  
Wan Abdul Aziz Wan Mohd Akib
Keyword(s):  
Large Scale ◽  
Aerial Photograph ◽  
Accuracy Assessment ◽  
Digital Camera ◽  
Conjugate Points ◽  
Ground Control Points ◽  
Thematic Mapping ◽  
Erdas Imagine ◽  
Aerial Vehicle ◽  
Low Altitude

Unmanned Aerial Vehicle (UAV) system offers many advantages in several applications such as topographic mapping, thematic mapping, slope mapping, geohazard studies, monitoring, etc. This study utilizes UAV system for large scale mapping by using a digital camera attached to a fixed wing UAV. The main objective of this study is to explore the potential of UAV for large scale mapping and to evaluate the accuracy of the photogrammetric output produced from the UAV system. The UAV was used to acquire low altitude aerial photograph based on photogrammetric technique and subsequently accuracy assessment is performed. The Ground Control Points (GCPs) and Check Points (CPs) were established using GPS rapid static technique for photogrammetric data processing. The GCPs were used in to produce 3D stereomodel and other photogrammetric output while the CP is used for accuracy assessment. For digital image processing of the aerial photograph and map production, Erdas Imagine 8.6 software is employed. For accuracy assessment, the coordinates of the selected points in the 3D stereomodel were compared to the conjugate points observed using GPS and the root mean square error (RMSE) is computed. From this study, the results showed that the achievable RMSE are ± 0.510 m, ± 0.564 m and ± 0.622 m for coordinates X, Y and Z respectively. For this study, the digital map was also produced using the photogrammetric technique and it is compared with an engineering plan produced from ground surveying technique (i.e. total station). From this study, it can be concluded that accuracy of sub-meter is achieved using the UAV system. Also, this study demonstrates that the UAV system has the potential for large scale mapping in the field of surveying and other diversified applications, especially for small area, minimum budget and less manpower. 

scholarly journals RESEARCH ON THE KEY TECHNOLOGY OF LARGE SCALE MAPPING FROM LOW ALTITUDE PHOTOGRAMMETRY

2016 ◽  
Vol XLI-B1 ◽  
pp. 789-796
Author(s):  
Wu Bo-Yi ◽  
Zhang Ning ◽  
Su Guo-Zhong
Keyword(s):  
Large Scale ◽  
Shanxi Province ◽  
Successful Implementation ◽  
Control Points ◽  
Theoretic Analysis ◽  
Ground Control Points ◽  
Traditional Procedure ◽  
Map Processing ◽  
Low Altitude ◽  
Wide Angle Camera

Based on the theoretic analysis of the accuracy in large scale photogrammetric mapping, some defects in traditional procedure were discussed. A set of key technologies dedicate to accuracy improvement in low altitude photogrammetry were analyzed in detail, namely the utilization of wide angle camera and low altitude flight, enhancement in image matching, predesigned layout of Ground Control Points (GCPs) in field survey, optimization of adjustment model and improvement in map processing. Besides, a low altitude aerial unmanned airship system was established. Finally, successful implementation in 1:500 topographic mapping project in built-up areas of 30 counties in Shanxi Province proves the practicability and effectiveness of the proposed approaches.

Fast Data Acquisition of Aerial Images Using Unmanned Aerial Vehicle System

2014 ◽  
Vol 3 (3) ◽  
pp. 162
Author(s):  
Norhadija Darwin ◽  
Anuar Ahmad
Keyword(s):  
Data Acquisition ◽  
Root Mean Square ◽  
Unmanned Aerial Vehicle ◽  
Large Scale ◽  
Digital Camera ◽  
Aerial Images ◽  
Mean Square ◽  
Fast Data Acquisition ◽  
Vehicle System ◽  
Aerial Vehicle

The present work discusses the technique and methodology of analysing the potential of fast data acquisition of aerial images using unmanned aerial vehicle system. This study utilizes UAV system for large scale mapping by using digital camera attached to the UAV. UAV is developed from the low-altitude photogrammetric mapping to perform the accuracy of the aerial photography and the resolution of the image. The Ground Control Points (GCPs) and Check Points (CPs) are established using Rapid Static techniques through GPS observation for registration purpose in photogrammetric process. The GCPs is used in the photogrammetric processes to produce photogrammetric output while the CP is employed for accuracy assessment. A Pentax Optio W90 consumer digital camera is also used in image acquisition of the aerial photograph. Besides, this study also involves image processing and map production using Erdas Imagine 8.6 software. The accuracy of the orthophoto is determined using the equation of Root Mean Square Error (RMSE). The final result from orthophoto is compared to the ground survey using total station to show the different accuracy of DEM and planimetric survey. It is discovered that root mean square errors obtained from UAV system are ± 0.510, ± 0.564 and ± 0.622 for coordinate x, y and z respectively. Hence, it can be concluded that the accuracy obtained from UAV system is achieved in sub meter. In a nutshell, UAV system has potential use for large scale mapping in field of surveying and other diversified environmental applications especially for small area which has limited time and less man power.

scholarly journals Accuracy Assessment of a UAV Block by Different Software Packages, Processing Schemes and Validation Strategies

2020 ◽  
Vol 9 (3) ◽  
pp. 164 ◽  
Author(s):  
Vittorio Casella ◽  
Filiberto Chiabrando ◽  
Marica Franzini ◽  
Ambrogio Maria Manzino
Keyword(s):  
Accuracy Assessment ◽  
Comparative Approach ◽  
Ground Control Points ◽  
Bundle Block Adjustment ◽  
Software Packages ◽  
Processing Strategies ◽  
High Resolution Imagery ◽  
Aerial Vehicle ◽  
Leave One Out ◽  
Validation Strategy

Unmanned aerial vehicle (UAV) systems are heavily adopted nowadays to collect high-resolution imagery with the purpose of documenting and mapping environment and cultural heritage. Such data are currently processed by programs based on the Structure from Motion (SfM) concept, coming from the computer vision community, rather than from classical photogrammetry. It is interesting to check whether some widely accepted rules coming from old-fashioned photogrammetry still holds: the relation between accuracy and ground sampling distance (GSD), the ratio between the vertical and horizontal accuracy, accuracy estimated on ground control points (GCPs) vs. that estimated with check points (CPs) also in relation to their ratio and distribution. To face the envisaged aspects, the paper adopts a comparative approach, as several programs are used and numerous configurations considered. The paper illustrates the dataset adopted, the carefully tuned processing strategies and bundle block adjustment (BBA) results in terms of accuracy for both GCPs and CPs. Finally, a leave-one-out (LOO) cross-validation strategy is proposed to assess the accuracy for one of the proposed configurations. Some of the reported results were previously presented in the 5th GISTAM Conference.

Assessment of Photogrammetric Micro Fixed-Wing Unmanned Aerial Vehicle (UAV) System For Image Acquisition of Coastal Area

2014 ◽  
Vol 71 (5) ◽  
Author(s):  
Norhadija Darwin ◽  
Anuar Ahmad ◽  
Zulkarnaini Mat Amin ◽  
Othman Zainon
Keyword(s):  
High Resolution ◽  
Unmanned Aerial Vehicle ◽  
Coastal Area ◽  
Image Acquisition ◽  
Digital Camera ◽  
Image Resolution ◽  
Aerial Images ◽  
Conjugate Points ◽  
Coastal Mapping ◽  
Aerial Vehicle

Fast image acquisition is the most important part for societal impact of a developing country. This paper aims to demonstrate the potential use of micro fixed wing unmanned aerial vehicle (UAV) system attached with high resolution digital camera for coastal mapping. In this study, six strips of aerial images of coastal area was captured using a high resolution compact digital camera known as Canon Power Shot SX230 HS and it has 12 megapixel image resolution. From the aerial images, photogrammetric image processing method is completed to produce mapping outputs such a digital elevation model (DEM) and orthophoto. For accuracy assessment, the coordinates of the selected points in the 3D of stereomodel were compared to the conjugate points observed using GPS and the root mean square error (RMSE) is computed. From this study, the results showed that the achievable RMSE are ± 0.018m, ± 0.013m and ± 0.034m for coordinates X, Y and Z respectively. It will anticipate that the UAV will be used for coastal survey and improve current method of producing with low cost, fast and good accuracy. Finally, the UAV has shown great potential to be used for coastal mapping that require accurate results or products using high resolution camera. 

scholarly journals Accuracy assessment of open - pit mine’s digital surface models generated using photos captured by Unmanned Aerial Vehicles in the post - processing kinematic mode

2021 ◽  
Vol 62 (4) ◽  
pp. 38-47
Author(s):  
Long Quoc Nguyen ◽  
Keyword(s):  
Accuracy Assessment ◽  
Open Pit ◽  
Ground Control ◽  
Surface Model ◽  
Control Points ◽  
Post Processing ◽  
Ground Control Points ◽  
Satellite Positioning ◽  
Surface Models ◽  
Aerial Vehicle

To evaluate the accuracy of the digital surface model (DSM) of an open-pit mine produced using photos captured by the unmanned aerial vehicle equipped with the post-processing dynamic satellite positioning technology (UAV/PPK), a DSM model of the Deo Nai open-pit coal mine was built in two cases: (1) only using images taken from UAV/PPK and (2) using images taken from UAV/PPK and ground control points (GCPs). These DSMs are evaluated in two ways: using checkpoints (CPs) and comparing the entire generated DSM with the DSM established by the electronic total station. The obtained results show that if using CPs, in case 1, the errors in horizontal and vertical dimension were 6.8 and 34.3 cm, respectively. When using two or more GCPs (case 2), the horizontal and vertical errors are at the centimetre-level (4.5 cm and 4.7 cm); if using the DSM comparison, the same accuracy as case 2 was also obtained.

scholarly journals Influence of the shape and size of the ground targets on the accuracy of photogrammetric processing

2020 ◽  
Vol 28 (3) ◽  
pp. 293-304
Author(s):  
Amr Elsheshtawy ◽  
Larisa A. Gavrilova ◽  
Anatoly N. Limonov ◽  
Mohamed Elshewy
Keyword(s):  
Large Scale ◽  
Soil Layer ◽  
Aerial Survey ◽  
Control Points ◽  
Aerial Photos ◽  
Emergency Situations ◽  
Ground Control Points ◽  
First Case ◽  
Aerial Vehicle ◽  
Mosaic Generation

The materials obtained from the unmanned aerial vehicle (UAV) are used to solve many problems, including large-scale mapping and monitoring of linear objects, as well as the ecological situation and monitoring of emergency situations. The promptly obtained photographic materials make it possible to reveal the consequences of man-made human impact associated with degradation of the soil cover, flooding of lands, salinization and pollution of the soil layer, and changes in the vegetation cover. Control points are used for absolute orientation of the generated models in the most projects of photogrammetric processing of aerial photos and images obtained from UAVs. In areas with low contour, before aerial survey, targeting is carried out in the required zones. The research is devoted to the study of the influence of the shape of ground targets on the accuracy of photogrammetric processing. It involved three different types of ground targets located on the land cover along the survey path at a distance not exceeding 1 m from each other. The targets were used as ground control points in the photogrammetric processing of the materials from the UAV. Two three-stripe photographic surveys of the 900 m long track were carried out: with UAV DJI PHANTOM 4 PRO camera FC6310 at a scale of 1:3400 and ground resolution of 1 cm and with the DJI Mavic PRO UAV camera FC220 at a scale of 1:12 700 and ground resolution of 2 cm. In both cases, the direction of flight is north - south, 36 targets were included in the photogrammetric processing. In the first case, 502 images were processed, in the second - 152. The photogrammetric processing for the orthophoto mosaic generation was carried out using the Agisoft Photo Scan Professional software. Four different contrasting sites in the study area were selected for the study: green grass, dry grass, clay, sand. Accuracy was assessed according to two criteria: 1) the degree of visualization of the target on the images; 2) the accuracy of the orthophoto mosaic, generated using various targets.

scholarly journals RESEARCH ON THE KEY TECHNOLOGY OF LARGE SCALE MAPPING FROM LOW ALTITUDE PHOTOGRAMMETRY

2016 ◽  
Vol XLI-B1 ◽  
pp. 789-796 ◽  
Author(s):  
Wu Bo-Yi ◽  
Zhang Ning ◽  
Su Guo-Zhong
Keyword(s):  
Large Scale ◽  
Shanxi Province ◽  
Successful Implementation ◽  
Control Points ◽  
Theoretic Analysis ◽  
Ground Control Points ◽  
Traditional Procedure ◽  
Map Processing ◽  
Low Altitude ◽  
Wide Angle Camera

Based on the theoretic analysis of the accuracy in large scale photogrammetric mapping, some defects in traditional procedure were discussed. A set of key technologies dedicate to accuracy improvement in low altitude photogrammetry were analyzed in detail, namely the utilization of wide angle camera and low altitude flight, enhancement in image matching, predesigned layout of Ground Control Points (GCPs) in field survey, optimization of adjustment model and improvement in map processing. Besides, a low altitude aerial unmanned airship system was established. Finally, successful implementation in 1:500 topographic mapping project in built-up areas of 30 counties in Shanxi Province proves the practicability and effectiveness of the proposed approaches.

scholarly journals Impact of UAV Surveying Parameters on Mixed Urban Landuse Surface Modelling

2020 ◽  
Vol 9 (11) ◽  
pp. 656
Author(s):  
Muhammad Hamid Chaudhry ◽  
Anuar Ahmad ◽  
Qudsia Gulzar
Keyword(s):  
Point Cloud ◽  
Large Scale ◽  
Accuracy Assessment ◽  
Computational Cost ◽  
Three Dimensional ◽  
Point Clouds ◽  
Ground Control ◽  
Control Points ◽  
Ground Control Points ◽  
High Computational Cost

Unmanned Aerial Vehicles (UAVs) as a surveying tool are mainly characterized by a large amount of data and high computational cost. This research investigates the use of a small amount of data with less computational cost for more accurate three-dimensional (3D) photogrammetric products by manipulating UAV surveying parameters such as flight lines pattern and image overlap percentages. Sixteen photogrammetric projects with perpendicular flight plans and a variation of 55% to 85% side and forward overlap were processed in Pix4DMapper. For UAV data georeferencing and accuracy assessment, 10 Ground Control Points (GCPs) and 18 Check Points (CPs) were used. Comparative analysis was done by incorporating the median of tie points, the number of 3D point cloud, horizontal/vertical Root Mean Square Error (RMSE), and large-scale topographic variations. The results show that an increased forward overlap also increases the median of the tie points, and an increase in both side and forward overlap results in the increased number of point clouds. The horizontal accuracy of 16 projects varies from ±0.13m to ±0.17m whereas the vertical accuracy varies from ± 0.09 m to ± 0.32 m. However, the lowest vertical RMSE value was not for highest overlap percentage. The tradeoff among UAV surveying parameters can result in high accuracy products with less computational cost.

scholarly journals ARE MEASURED GROUND CONTROL POINTS STILL REQUIRED IN UAV BASED LARGE SCALE MAPPING? ASSESSING THE POSITIONAL ACCURACY OF AN RTK MULTI-ROTOR PLATFORM

2020 ◽  
Vol XLIII-B1-2020 ◽  
pp. 507-514 ◽  
Author(s):  
L. Teppati Losè ◽  
F. Chiabrando ◽  
F. Giulio Tonolo
Keyword(s):  
Large Scale ◽  
Control Point ◽  
Satellite System ◽  
Added Value ◽  
Ground Control ◽  
Positional Accuracy ◽  
Ground Control Points ◽  
Aerial Vehicle ◽  
Global Navigation Satellite ◽  
The Impact

Abstract. The estimate of External Orientation (E.O.) parameters for a block of images is a crucial step in the photogrammetric pipeline and the most demanding in terms of required time and human effort, both during the fieldwork and post-processing phases. Different researchers developed strategies to minimize the impact of this phase. Despite the achievement of good results, it was not possible until now to completely cancel the effect of this step. However, the efforts of the researchers in these years have also been devoted to the implementation of direct photogrammetry strategies, in order to almost completely automate the E.O. of the photogrammetric block. These new approaches were made possible also thanks to the latest developments of commercial UAVs, especially in terms of the installed GPS/GNSS (Global Positioning System/Global Navigation Satellite System) hardware. The aim of this manuscript is to evaluate the different perspectives and issues connected with the deployment of a UAV (Unmanned Aerial Vehicle) equipped with a multi-frequency GPS/GNSS receiver. Starting from the considerations mentioned above and leveraging previous works based on a fixed-wing platform, the focus of this contribution is the assessment of the real performances of an RTK multi-rotor platform addressing several questions. Is it possible to generate added-value products with centimetre 3D accuracies without measuring any ground control point? Which are the operational requirements to be taken into account in the planning phase? Are consolidated UAV mapping operational workflows already available to enable a robust direct georeferencing approach?

scholarly journals Accuracy Assessment of 3D Photogrammetric Models from an Unmanned Aerial Vehicle

Drones ◽  
2019 ◽  
Vol 3 (4) ◽  
pp. 79 ◽  
Author(s):  
Salvatore Barba ◽  
Maurizio Barbarella ◽  
Alessandro Di Benedetto ◽  
Margherita Fiani ◽  
Lucas Gujski ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Accuracy Assessment ◽  
Archaeological Site ◽  
Test Case ◽  
Accuracy Rate ◽  
Entire Area ◽  
Final Model ◽  
Ground Control Points ◽  
Aerial Vehicle ◽  
Definition Of

The unmanned aerial vehicle (UAV) photogrammetric survey of an archaeological site has proved itself to be particularly efficient. In order to obtain highly accurate and reliable results, it is necessary to design carefully the flight plan and the geo-referencing, while also evaluating the indicators of the accuracy rate. Using as a test case a UAV photogrammetric survey conducted on the archaeological site of the Roman Amphitheatre of Avella (Italy), in this paper, we propose a pipeline to assess the accuracy of the results according to some quality indicators. The flight configuration and the georeferencing chosen is then be checked via the residuals on the ground control points (GCPs), evenly distributed on the edges and over the entire area. With the aim of appraising the accuracy of the final model, we will suggest a method for the outlier detection, taking into account the statistical distribution (both global and of portion of the study object) of the reprojection errors. A filter to reduce the noise within the model will then be implemented through the detection of the angle formed by homologous rays, in order to reach a compromise between the number of the usable points and the reduction of the noise linked to the definition of the 3D model.

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