Design, Implementation and Simulation of an Experimental Multi-Camera Imaging System for Terrestrial and Multi-Purpose Mobile Mapping Platforms: A Case Study

Mobile Mapping Systems (MMS’s) are powerful tools for rapidly and massively collecting imagery in various environments (e.g., rural, semi-urban, urban). In particular, the data collected at terrestrial level can be exploited to complement aerial acquisitions for extending GIS databases,visualizing and modeling urban environments and studying environment morphogenesis over time. Hence, the development of mobile mapping platforms is a topic of great interest for many mapping agencies and surveying companies. Moreover, the experimental imaging systems of mapping vehicles are equipped with varied infrastructures in part resulting from the wide range of targeted applications. Determining a detailed design procedure for such imaging systems is of critical importance, and can be both arduous and time-consuming. Although commercial imaging systems can be exploited directly they are often pre-configured for specific applications. For these reasons, we propose a case study that deals with the development of an orientable and scalable imaging system. In particular, this paper focusses on the primary stage of the mechanical implementation of a multi-camera infrastructure. To this effect, we provide a design document that includes full technical specifications and drawings for creating a roof-mounted camera mast from a vehicle platform. We also provide an inventory of resources required for creating the system. As part of the design process we analyse some well-known MMS’s paying particular attention to their imaging systems. Finally, we evaluate the proposed design by creating the complete 3D mock-up of the camera system at real-scale and by simulating camera configurations from an experimental van platform. Experimental results clearly show the usefulness of this study in the design of an experimental and multi-purpose imaging system.

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HYBRID MODELS FOR TRAJECTORY ERROR MODELLING IN URBAN ENVIRONMENTS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xli-b3-805-2016 ◽

2016 ◽

Vol XLI-B3 ◽

pp. 805-811

Author(s):

E. Angelatsa ◽

M. E. Parés ◽

I. Colomina

Keyword(s):

Error Function ◽

Real Data ◽

Continuous Functions ◽

Error Component ◽

Urban Environments ◽

Mobile Mapping ◽

Trajectory Error ◽

Mapping System ◽

Wide Range ◽

Mobile Mapping System

This paper tackles the first step of any strategy aiming to improve the trajectory of terrestrial mobile mapping systems in urban environments. We present an approach to model the error of terrestrial mobile mapping trajectories, combining deterministic and stochastic models. Due to urban specific environment, the deterministic component will be modelled with non-continuous functions composed by linear shifts, drifts or polynomial functions. In addition, we will introduce a stochastic error component for modelling residual noise of the trajectory error function. First step for error modelling requires to know the actual trajectory error values for several representative environments. In order to determine as accurately as possible the trajectories error, (almost) error less trajectories should be estimated using extracted nonsemantic features from a sequence of images collected with the terrestrial mobile mapping system and from a full set of ground control points. Once the references are estimated, they will be used to determine the actual errors in terrestrial mobile mapping trajectory. The rigorous analysis of these data sets will allow us to characterize the errors of a terrestrial mobile mapping system for a wide range of environments. This information will be of great use in future campaigns to improve the results of the 3D points cloud generation. The proposed approach has been evaluated using real data. The data originate from a mobile mapping campaign over an urban and controlled area of Dortmund (Germany), with harmful GNSS conditions. The mobile mapping system, that includes two laser scanner and two cameras, was mounted on a van and it was driven over a controlled area around three hours. The results show the suitability to decompose trajectory error with non-continuous deterministic and stochastic components.

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Realising embedded stiffness in hydraulic implementations of stiffness-damping-inertance configurations

Journal of Vibration and Control ◽

10.1177/10775463211033726 ◽

2021 ◽

pp. 107754632110337

Author(s):

Sara Y Zhang ◽

Hui Yuan ◽

Jason Z Jiang ◽

Simon Neild ◽

Wei-Xin Ren

Keyword(s):

Vibration Suppression ◽

Ride Comfort ◽

Design Procedure ◽

Membrane Properties ◽

Passenger Vehicle ◽

Rubber Membrane ◽

Nonlinear Properties ◽

Wide Range ◽

In Series

The performance benefits of passive vibration suppression with network configurations consisting of stiffness, damping and inertance elements have been demonstrated for a wide range of mechanical systems. Considering physical implementations of these beneficial network configurations, hydraulic realisations have the advantages of durability and simplicity for integration with existing hydraulic dampers. Such designs are exemplified by fluid inerters and fluid-inerter-damper devices. However, in contrast to the convenience of realising inertance and damping elements, realising ‘embedded’ stiffness is very challenging. We use ‘embedded’ to refer to a network element, which is not purely in series or in parallel with the remainder of the network but instead lies within the network layout. In this work, a setup using a rubber membrane to realise such embedded stiffness is proposed, together with a procedure for hydraulic implementations of any stiffness-damping-inertance configurations. The nonlinear properties of the embedded stiffness due to rubber membrane properties are then investigated both theoretically and experimentally. In addition, the effectiveness of both the membrane setup and the design procedure are demonstrated via a case study of suspension design for passenger vehicle ride comfort enhancement.

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HYBRID MODELS FOR TRAJECTORY ERROR MODELLING IN URBAN ENVIRONMENTS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsarchives-xli-b3-805-2016 ◽

2016 ◽

Vol XLI-B3 ◽

pp. 805-811

Author(s):

E. Angelatsa ◽

M. E. Parés ◽

I. Colomina

Keyword(s):

Error Function ◽

Real Data ◽

Continuous Functions ◽

Error Component ◽

Urban Environments ◽

Mobile Mapping ◽

Trajectory Error ◽

Mapping System ◽

Wide Range ◽

Mobile Mapping System

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STRATEGIES TO INTEGRATE IMU AND LIDAR SLAM FOR INDOOR MAPPING

ISPRS Annals of Photogrammetry Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-annals-v-1-2020-223-2020 ◽

2020 ◽

Vol V-1-2020 ◽

pp. 223-230

Author(s):

S. Karam ◽

V. Lehtola ◽

G. Vosselman

Keyword(s):

Facility Management ◽

Measurement Unit ◽

Reconstruction Accuracy ◽

Mobile Mapping ◽

Localization And Mapping ◽

Satellite Positioning ◽

Wide Range ◽

Six Degree Of Freedom ◽

Mobile Mapping Systems ◽

Mapping Systems

Abstract. In recent years, the importance of indoor mapping increased in a wide range of applications, such as facility management and mapping hazardous sites. The essential technique behind indoor mapping is simultaneous localization and mapping (SLAM) because SLAM offers suitable positioning estimates in environments where satellite positioning is not available. State-of-the-art indoor mobile mapping systems employ Visual-based SLAM or LiDAR-based SLAM. However, Visual-based SLAM is sensitive to textureless environments and, similarly, LiDAR-based SLAM is sensitive to a number of pose configurations where the geometry of laser observations is not strong enough to reliably estimate the six-degree-of-freedom (6DOF) pose of the system. In this paper, we present different strategies that utilize the benefits of the inertial measurement unit (IMU) in the pose estimation and support LiDAR-based SLAM in overcoming these problems. The proposed strategies have been implemented and tested using different datasets and our experimental results demonstrate that the proposed methods do indeed overcome these problems. We conclude that IMU observations increase the robustness of SLAM, which is expected, but also that the best reconstruction accuracy is obtained not with a blind use of all observations but by filtering the measurements with a proposed reliability measure. To this end, our results show promising improvements in reconstruction accuracy.

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ROBUST RESECTION MODEL FOR ALIGNING THE MOBILE MAPPING SYSTEMS TRAJECTORIES AT DEGRADED AND DENIED URBAN ENVIRONMENTS

ISPRS Annals of Photogrammetry Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-annals-v-1-2020-215-2020 ◽

2020 ◽

Vol V-1-2020 ◽

pp. 215-222

Author(s):

B. Alsadik

Keyword(s):

Real Data ◽

Experimental Tests ◽

Urban Environments ◽

Mobile Mapping ◽

Positioning Accuracy ◽

Pose Determination ◽

Panoramic Images ◽

The Absolute ◽

Mobile Mapping Systems ◽

Mapping Systems

Abstract. Mobile mapping systems MMS equipped with cameras and laser scanners are widely used nowadays for different geospatial applications with centimetric accuracy either in project wise or national wise scales. The achieved positioning accuracy is very much related to the navigation unit, namely the GNSS and IMU onboard. Accordingly, in GNSS denied and degraded environments, the absolute positioning accuracy is worsened to few meters in some cases. Frequently, ground control points GCPs of a high positioning accuracy are used to align the MMS trajectories and to improve the accuracy when needed.The best way to integrate the MMS trajectories to the GCPs is by measuring them on the MMS images where the positioning accuracy is dropped. MMS images are mostly spherical panoramic (equirectangular) images and sometimes perspective and, in both types, it is required to precisely determine the images orientation in what is called as space resection or camera pose determination. For perspective images, the pose is conventionally determined by collinearity equations or by using projection and fundamental matrices. Whereas for equirectangular panoramic images it is based on resecting vertical and horizontal angles. However, there is still a challenge in the state–of–the–art of image pose determination because of the model nonlinearity and the sensitivity to proper initialization and spatial distribution of the points.In this research, a generic method is presented to solve the pose resection problem for the perspective and equirectangular images using oblique angles. The oblique angles are derived from the measured image coordinates and based on spherical trigonometry rules and vector geometry. The developed algorithm has proven to be highly stable and steadily converge to the global minimum. This is related to the robust geometric constraint offered by the oblique angles that are enclosed between the object points and the camera. As a result, the MMS trajectories are realigned accurately to the GCPs and the absolute accuracy is highly refined. Four experimental tests are presented where the results show the efficiency of the proposed angular based model in different cases of simulated and real data with different image types.

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Site specific agricultural soil management with the use of new technologies

Global NEST Journal ◽

10.30955/gnj.001203 ◽

2013 ◽

Vol 16 (1) ◽

pp. 59-67

Keyword(s):

New Technologies ◽

Digital Interface ◽

Appropriate Treatment ◽

Wide Range ◽

Soil Variation ◽

Soil Information ◽

Remote Sensing Techniques ◽

Agricultural Areas

The Soil Science Institute of Thessaloniki produces new digitized Soil Maps that provide a useful electronic database for the spatial representation of the soil variation within a region, based on in situ soil sampling, laboratory analyses, GIS techniques and plant nutrition mathematical models, coupled with the local land cadastre. The novelty of these studies is that local agronomists have immediate access to a wide range of soil information by clicking on a field parcel shown in this digital interface and, therefore, can suggest an appropriate treatment (e.g. liming, manure incorporation, desalination, application of proper type and quantity of fertilizer) depending on the field conditions and cultivated crops. A specific case study is presented in the current work with regards to the construction of the digitized Soil Map of the regional unit of Kastoria. The potential of this map can easily be realized by the fact that the mapping of the physicochemical properties of the soils in this region provided delineation zones for differential fertilization management. An experiment was also conducted using remote sensing techniques for the enhancement of the fertilization advisory software database, which is a component of the digitized map, and the optimization of nitrogen management in agricultural areas.

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Wastewater treatment and nutrient removal in the combined reactor

Water Science & Technology ◽

10.2166/wst.1998.0023 ◽

1998 ◽

Vol 38 (1) ◽

pp. 87-95 ◽

Cited By ~ 2

Author(s):

M. Roš ◽

J. Vrtovšek

Keyword(s):

Organic Compounds ◽

Industrial Wastewater ◽

Design Procedure ◽

Order Reaction ◽

Treated Wastewater ◽

Nitrification Rate ◽

Zero Order Reaction ◽

Aerobic Reactor ◽

Complex Organic

A combined anaerobic anoxic aerobic reactor for the treatment of the industrial wastewater that contains nitrogen and complex organic compounds as well as its design procedure is presented. The purpose of our experiments was to find a simple methodology that would provide combined reactor design. The reactor is based on the combination of anaerobic, anoxic and aerobic process in one unit only. It was found that the HRT even under 1 hour in the anaerobic zone is long enough for the efficient transformation of complex organic compounds into readily biodegradable COD which is then used in dentrification process. In the N-NO3 concentration range 1.5-50 mg/l the denitrification rate could be expressed as half-order reaction when the CODrb was in excess. N-NO3 removal efficiency is controlled by the recycle flow from the aerobic to the anoxic zone. Nitrification rate can be expressed as first, half or zero-order reaction with respect to effluent N-NH4 concentration. Nitrification rate depends on the dissolved oxygen concentration and hydrodynamic conditions in the reactor. Case study for design of a pilot plant of the combined reactor for treatment of pre-treated pharmaceutical wastewater is shown. Characteristics of pre-treated wastewater were: COD=200 mg/l, BOD5=20 mg/l, N-Kjeldahl=80 mg/l, N-NH4=70 mg/l, N-NOx<1 mg/l, P-PO4=5 mg/l. Legal requirements for treated wastewater were: COD=<100 mg/l, BOD5<5 mg/l, N-NH4=<1 mg/l, N-NOx=<10 mg/l.

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Oxford Studies in Ancient Philosophy, Volume 55

10.1093/oso/9780198836339.001.0001 ◽

2018 ◽

Keyword(s):

Middle Ages ◽

Ancient Philosophy ◽

Recent Book ◽

Loss Of Control ◽

Ancient Greek ◽

Original Essays ◽

Constant Change ◽

Wide Range ◽

Metaphysical Principle

Oxford Studies in Ancient Philosophy provides, twice each year, a collection of the best current work in the field of ancient philosophy. Each volume features original essays that contribute to an understanding of a wide range of themes and problems in all periods of ancient Greek and Roman philosophy, from the beginnings to the threshold of the Middle Ages. From its first volume in 1983, OSAP has been a highly influential venue for work in the field, and has often featured essays of substantial length as well as critical essays on books of distinctive importance. Volume LV contains: a methodological examination on how the evidence for Presocratic thought is shaped through its reception by later thinkers, using discussions of a world soul as a case study; an article on Plato’s conception of flux and the way in which sensible particulars maintain a kind of continuity while undergoing constant change; a discussion of J. L. Austin’s unpublished lecture notes on Aristotle’s Nicomachean Ethics and his treatment of loss of control (akrasia); an article on the Stoics’ theory of time and in particular Chrysippus’ conception of the present and of events; and two articles on Plotinus, one that identifies a distinct argument to show that there is a single, ultimate metaphysical principle; and a review essay discussing E. K. Emilsson’s recent book, Plotinus.

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EXPRESS: Design Considerations for Discrete Frequency Infrared Microscopy Systems

Applied Spectroscopy ◽

10.1177/00037028211013372 ◽

2021 ◽

pp. 000370282110133

Author(s):

Rohit Bhargava ◽

Yamuna Dilip Phal ◽

Kevin Yeh

Keyword(s):

Imaging System ◽

Chemical Imaging ◽

Optical Component ◽

Imaging Systems ◽

Imaging Data ◽

Discrete Frequency ◽

Figures Of Merit ◽

Design Considerations ◽

Hardware Implementations ◽

Measurement Capabilities

Discrete frequency infrared (DFIR) chemical imaging is transforming the practice of microspectroscopy by enabling a diversity of instrumentation and new measurement capabilities. While a variety of hardware implementations have been realized, considerations in the design of all-IR microscopes have not yet been compiled. Here we describe the evolution of IR microscopes, provide rationales for design choices, and the major considerations for each optical component that together comprise an imaging system. We analyze design choices in illustrative examples that use these components to optimize performance, under their particular constraints. We then summarize a framework to assess the factors that determine an instrumentâs performance mathematically. Finally, we summarize the design and analysis approach by enumerating performance figures of merit for spectroscopic imaging data that can be used to evaluate the capabilities of imaging systems or suitability for specific intended applications. Together, the presented concepts and examples should aid in understanding available instrument configurations, while guiding innovations in design of the next generation of IR chemical imaging spectrometers.

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