Search results for "Photogrammetry"

Processing and Assessment of Spectrometric, Stereoscopic Imagery Collected Using a Lightweight UAV Spectral Camera for Precision Agriculture

2013

Imaging using lightweight, unmanned airborne vehicles (UAVs) is one of the most rapidly developing fields in remote sensing technology. The new, tunable, Fabry-Perot interferometer-based (FPI) spectral camera, which weighs less than 700 g, makes it possible to collect spectrometric image blocks with stereoscopic overlaps using light-weight UAV platforms. This new technology is highly relevant, because it opens up new possibilities for measuring and monitoring the environment, which is becoming increasingly important for many environmental challenges. Our objectives were to investigate the processing and use of this new type of image data in precision agriculture. We developed the entire pro…

Individual Tree Detection and Classification with UAV-Based Photogrammetric Point Clouds and Hyperspectral Imaging

2017

Made available in DSpace on 2018-12-11T17:11:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-03-01 Suomen Akatemia Small unmanned aerial vehicle (UAV) based remote sensing is a rapidly evolving technology. Novel sensors and methods are entering the market, offering completely new possibilities to carry out remote sensing tasks. Three-dimensional (3D) hyperspectral remote sensing is a novel and powerful technology that has recently become available to small UAVs. This study investigated the performance of UAV-based photogrammetry and hyperspectral imaging in individual tree detection and tree species classification in boreal forests. Eleven test sites with 4151 reference trees repr…

Social Lives of Monumental Walls: Hunting along the Upper Tigris

2021

On the left bank of the Tigris in northern Iraq, in an area today partially flooded by the Mosul Dam reservoir, lies an enigmatic monumental enclosure known in the literature as the “Tigris Wall.” Before its partial submersion under the waters of the modern lake, the large L-shaped embankment, about 4 × 4 km long, enclosed an area of ca. 1600 ha, overlooking the Tigris and its alluvial plain. By means of a holistic strategy that includes different levels of analysis (remote sensing, pedestrian and UAV photogrammetric surveys, excavation, and settlement pattern analysis), this paper addresses the structure, its context, and its environment. Relying on the results of this multi-disciplinary a…

Unmanned Aerial Vehicle (UAV) Survey with Commercial-Grade Instruments: A Case Study from the Eastern Ḫabur Archaeological Survey, Iraq

2018

Low-altitude photography in archaeology is now common practice at the scale of excavations; however, landscape-scale applications are a relatively new endeavor with promising analytical potential. From 2014–2016, an unmanned aerial vehicle (UAV) with a mounted camera was used to document sites recorded as part of the Eastern Ḫabur Archaeological Survey (EḪAS), an archaeological reconnaissance project in western Dohuk Province, Iraqi Kurdistan. The EḪAS team documented over 70 archaeological sites with the UAV, from single-phase artifact scatters, to archaeological remains with standing architecture, to tells that cover more than 30 hectares. Representative examples from this survey are pres…

Assessing the accuracy of industrial robots through metrology for the enhancement of automated non-destructive testing

2016

This work presents the study of the accuracy of an industrial robot KR5 arc HW, used to perform quality inspections of components with complex shapes. Metrology techniques such as laser tracking and large volume photogrammetry were deployed to quantify both pose and dynamic path accuracies of the robot in accordance with ISO 9283:1998. The overall positioning pose inaccuracy of the robot is found to be almost 1 mm and path inaccuracy at 100% of the robot rated velocity is 4.5 mm. The maximum pose orientation inaccuracy is found to be 14 degrees and the maximum path orientation inaccuracy is 5 degrees. Despite of the significant maximum inaccuracies, uncertainty of a robotic scanning applica…

Using UAV Based 3D Modelling to Provide Smart Monitoring of Road Pavement Conditions

2020

Road pavements need adequate maintenance to ensure that their conditions are kept in a good state throughout their lifespans. For this to be possible, authorities need efficient and effective databases in place, which have up to date and relevant road condition information. However, obtaining this information can be very difficult and costly and for smart city applications, it is vital. Currently, many authorities make maintenance decisions by assuming road conditions, which leads to poor maintenance plans and strategies. This study explores a pathway to obtain key information on a roadway utilizing drone imagery to replicate the roadway as a 3D model. The study validates this by using stru…

A new approach to Road Pavement Management Systems by exploiting Data Analytics, Image Analysis and Deep Learning

2021

PERFORMANCE EVALUATIONS OF 3D WEB-SERVICES AND OPEN-SOURCE SOFTWARE FOR DIGITAL MODELING OF ARCHAEOLOGICAL FINDS

2016

The Structure From Motion (SFM) algorithms derived from Computer Vision community make image-based techniques a competitive and user friendly approach to obtain 3D information of real objects. These algorithms have been implemented in many 3D web-services and open-source software to develop free instruments for the reconstruction of very detailed 3D digital models. Their use is becoming very common above all in archaeological studies but their potentiality for metric application has not been tested at all. The aim of the work is to investigate the quality and the accuracy of 3D models obtained through 3D web-services and SFM open-source software. Different tests have been performed using so…

SfM Techniques Applied in Bad Lighting and Reflection Conditions: The Case of a Museum Artwork

2019

In recent years, SfM techniques have been widely used especially in the field of Cultural Heritage. Some applications, however, remain undefined in cases where the boundary conditions are not suitable for the technique. Examples of this are instances where there are poor lighting conditions and the presence of glass and reflective surfaces. This paper presents a case study where SfM is applied, using a DSLR camera (Nikon D5200), to the “Head of Hades” inside a glass theca and under a large number of light sources at different distances and of different intensities and sizes. The geometric evaluation has been made comparing the DSLR camera model against the 3D data acquired with structured l…

3D Image Based Modelling Using Google Earth Imagery for 3D Landscape Modelling

2019

In recent years SfM technique experiments have been innumerable and increasingly refined under metric profiles. The techniques rely on photographic datasets of the objects or landscapes which can require in most cases time consuming and expensive surveys. Recently however there have been increases in the available 3D data of sites worldwide on the Google Earth (GE) platform. This paper presents a unique experimentation that considers integrating readily available datasets from GE and images taken during surveys on ground level for 3D replication without the use of expensive aerial surveys. This will enable practitioners the ability to more easily create 3D models of cultural heritage signif…