Surveying technologies overview

This page displays a list of all surveying technologies available. Click on the link of a surveying technology for further details.

Surveying technology	Surveying technology type	Used for Civil engineering types	Used for Materials	Physical quantities measured	Main objective	Advantages	Disadvantages
Acoustic Emission techniques (AE)	Non-destructive	Bridge Tunnel Viaduct Building	Steel Composite Technical ceramic Concrete Polymer	Displacement Cracks Deformation Wire breaks Delamination Rupture Reinforment bar failure and bending Debonding Holes Loss of section	To provide information about possible catastrophic failures or evaluation of the level of damage in different materials and industries	both local and global measurement possible no interference with the traffic on the bridge remote navigation and analysis of the data customized alarm system upon reaching user-defined damage thresholds internal storage of the data power saving options compatibility with different power sources and batteries simple connection to the base station.	requirement of two-sided access to a given measurement site sensitivity to the differences in the moisture content of the concrete surface sensitivity to the presence of reinforcing bars difficulty with measurements, when complex geometry is given difficulty with measurements when large number of defects is present more suitable for new bridges and construction as a supplement for standard inspection.
Aerial UAV with optical payloads					In order to measure and monitor the environment, these vehicles can carry optical imaging sensors, such as Light Detection and Ranging (LiDAR), Synthetic Aperture Radar (SAR) and NDT payloads. The measurements can be georeferenced by the navigation system and the attitude sensors of the vehicle, generally based on Global Navigation Satellite Systems (GNSS) and Inertial Measurement Units (IMU)	Lower risk for practitioners and operators Access to hard-to-reach areas such as deck bottoms Robust Data acquisition in high components Better site visibility and aerial point of view of the system Cost-effective technique for surveying Speed-up the process in field compared to manual data acquisition Pre-defined risk scenarios for the operation that simplify the planification phase.	Limited flight time -Autonomy of the system Payload weight limited by Maximum Take Off Weight and regulations. Even though there is a EU regulation defined by European Aviation Safety Agency (EASA), the National regulation and local permissions are not standardized. Mixed between operational safety and System Certification Operational constraints including Visual Line of Sight (VLOS) restrictions. Subject to field conditions, including weather condition Navigation solutions for interesting areas, such as deck bottoms More complex planification phase. Low Readiness Level for a number of inspection applications, such as Aerial Robotics Limitation for Real-Time data and postprocessing procedures.
Fibre optic sensors	Non-destructive	Bridge Tunnel	Steel Composite Wood Concrete Reinforced Concrete	Displacement Cracks Deformation Wire breaks Delamination Tensioning force deficiency Rupture Stirrup rupture Obstruction and impeding Debonding Holes Loss of section Deteriorated mortar joints	The assessment of the structural integrity or performance of civil structures. FOS technology allows to measure the bridge/tunnel performance under traffic loads and store the information globally with expanding modern data storage solutions.	Possibility of continuous measurement along the length of the monofilament, and therefore also along the length of the structural element to which the fiber has been attached; Allows replacement of plenty of traditional sensors with one single optical fiber; Longer lifetime compared to conventional resistance strain sensors; Long-term signal stability under unfavorable conditions; Possibility of placing several sensors on the same fiber; Resistance to interference; Cost of the measurement system is relatively low, easy to install, highly sensitive, compact in size.	Optical fibres are fragile and prone to damage during use. Care should be taken while use.
Ground Penetrating Radar (GPR)	Non-destructive	Bridge Tunnel Viaduct	Rock Wood Concrete Reinforced Concrete Brick Stone	Spalling Cracks Delamination Reinforcement bar corrosion Debonding Holes Loss of section	GPR is a geophysical method that allows for the analysis of the propagation capacity of electromagnetic waves through media with different dielectric constants.	Non-destructive and non-invasive method. Easy transportation. Fast data acquisition compared with other geophysical methods. Imaging of the subsoil with high resolution. Precise vertical and horizontal positioning. Results are displayed in real-time.	The interpretation of radargrams is generally non-intuitive and requires considerable expertise to properly process and understand the measurements. Uncertainty/inaccuracy in depth/thickness estimation (pre-calibrated media characterization and accurate wave velocity of propagation are needed).
Guided Waves Propagation (GW) techniques	Non-destructive	Bridge Viaduct	Steel Composite Concrete Polymer Glass fibres	Spalling Displacement Cracks Wire breaks Delamination Tensioning force deficiency Vibration and oscillation Frequency Stirrup rupture Obstruction and impeding Reinforment bar failure and bending Debonding Holes Loss of section	Detection of the damage in structural health monitoring of the reinforced concrete can be studied with guided waves propagation survey as a promising and non-destructive testing.	propagation over long distances sensitivity to different type of flaws detection of damages from remote position, with use of surface-mounted sensors combined with ultrasonic tomography give information such as localization of the damages in the cross-section, degree of degradation, determination of which rebars are damaged performance over long range with an accurate sensitivity testing of multi-layered structures fully automated data collection	different damage configurations requires numerical analysis difficulties in extracting desired wave modes dependence on the thickness and shape interpretation of the results highly dependent on the operator.
Light Detection And Ranging or Laser Imaging Detection And Ranging (LiDAR)	Non-destructive	Bridge Tunnel Viaduct Building	Steel Wood Concrete Glass Forest and other vegetation Environment in general Stone	Spalling Displacement Cracks Deformation Crushing Rupture Holes	LiDAR technology is used to obtain three-dimensional (3D) representations of objects or structures	Big amounts of data (Big Data) Short data acquisition time High accuracy Day and night operation (active sensor) Easy integration with other technologies (RGB, Thermography…) Access to unreachable areas (MLS) Continuous data acquisition	Need of experts for surveys’ performing Need for large data storage Not many automated process High processing time Sensitive to other reflections (e.g. sunlight) (MLS) Reliance on navigation system performance for point referencing (TLS) Limited to a single standpoint per acquisition Expensive data collection for small areas No international protocols
Magnetic and electrical methods	Non-destructive	Bridge Tunnel	Steel Concrete Ferromagnetic material Polymer Coating Reinforced Concrete Silicate	Cracks Delamination Reinforment bar failure and bending Loss of section	Electromagnetic methods have been widely used in detection of corrosion in post-tensioned concrete elements. In case of bridge infrastructure management, the most used techniques are based on the electromagnetic pulse induction technology.	Electromagnetic Pulse Induction Methods: fast and easy to operate simple read-out of the results not affected by environmental influences Magnetic Memory Method (MMM): low-cost magnetoresistive sensors used allows real-time monitoring good sensitivity in wide range of magnetic field fluctuations detection of early damages Magnetic Flux Leakage Method (MFL): very powerful in scanning a large areas efficient and easy operation Pulsed Eddy Current Response (PEC): can be done without need for contact with the surface of the material useful in situations where an object’s surface is rough or inaccessible does not require surface preparation or removing any insulation. It can be a quick and cost-effective solution for corrosion detection possibility of location of the reinforcement and dimensions of the rebars with high accuracy quality control of the cover of reinforcing bars after concrete placement possibility of studying the elements for which no records or historical data are available good sensitivity to pitting high-speed inspection.	– Electromagnetic Pulse Induction methods: dependency on cover depths for minimum bar spacing detection restricted detection range – Magnetic Memory Method (MMM): signals are prone to be easily interfered low repeatability and reliability – Magnetic Flux Leakage Method (MFL): very poor for detecting axial cracks dimensions of the defects are limited – Pulsed Eddy Current Response (PEC): impossible detection of small pitting
Mechanical tests on cored samples	Destructive	Bridge Tunnel Viaduct	Steel Composite Alloy Concrete Metal Polymer Nanocomposite Silicate	Displacement Cracks Deformation Wire breaks Delamination Tensioning force deficiency Rupture Prestressing cable Stirrup rupture Obstruction and impeding Reinforment bar failure and bending Debonding Holes Loss of section	Mechanical tests performed on hardened concrete are a part of destructive surveying techniques used for characterization of concrete properties, such as compressive strength, that will affect the durability of the different structural elements of bridges or tunnels.	Used core samples are qualitatively better material than those from the laboratory, because they contain all potential defects resulting from various technological and transport situations or climatic influence. Testing the strength of hardened concrete is particularly useful, because the quality of the concrete in structure depends to a large extent on this property. Based on the static strength tests it is possible to conclude if the analysed bridge structure can still transfer utility loads with accordance to norm.	All methods induce damage to the structures which can cause risk during works and require repairs. In practical situation drilled sample taken may not be a good representation of the entire structure, which leads to inaccuracies and doubts.
Micro Electro-Mechanical Systems (MEMS) - Accelerometers	Non-destructive	Bridge Building		Prestressing cable failure Tensioning force deficiency Vibration and oscillation Frequency Reinforment bar failure and bending Loss of section	One application of MEMS sensors are accelerometers, that measure linear acceleration and allow the analysis of vibrations and structures dynamic behaviour.	Low-cost technology. Applicable in a continuous SHM system. Easy transportation and installation Small size Depending on the application, sensors can be set with different parameters.	Not suitable when operational applications are characterized by low level inputs, due to their noise floor.
Micro Electro-Mechanical Systems (MEMS) - Clinometers	Non-destructive	Bridge Tunnel		Deformation Reinforment bar failure and bending Loss of section	They derive from MEMS accelerometers and measure the inclination with respect to the horizontal axis. For this reason, they are useful to analyse structures static behaviour.	Low-cost technology. Applicable in a continuous SHM system. Easy transportation and installation Small size Depending on the application, sensors can be set with different parameters.	High measurement accuracy only around small angles. Only rotations around axis laying in the horizontal plane can be measured.
Optical and visual testing - Boroscopy and Endoscopy	Non-destructive	Bridge Tunnel Viaduct Building	Steel Composite Technical ceramic Concrete Polymer	Cracks Deformation Rupture Obstruction and impeding Holes	Optical and visual testing have been widely known in the diagnostics of civil engineer structures, since methods are easily available and do not require large expenditures and effort in application	Recording directly on the memory card. Small diameter of the camera to pass through the tiniest holes. Various photo resolution settings and low cost. The durability guaranteed by stainless steel construction of the device.	Experience of the operator required to properly understand observed issues.
Qualitative chemical methods	Destructive	Bridge Tunnel Viaduct	Building lime Technical ceramic Concrete Gravel Ferroalloy Aggregate Slag Cement Pigment	Spalling Displacement Cracks Delamination Reinforcement bar corrosion Obstruction and impeding Debonding Loss of section	Chemical methods based on pH determination are widely used for inspection of the carbonation front depth, and determination of whether the standard pH of concrete has been changed under environmental conditions.	pH indicators: easy feasible no specific training required measurements can be performed in laboratory or on the construction site easy to repeat. Uranyl-Acetate Treatment: high contrast between damaged and not damaged areas easy to repeat. Half-cell potentials method: widely known technology not expensive equipment. Electrical resistivity tomography: enables creation of internal maps of the structure. Infrared Spectroscopy: accurate and precise enables identification of the structure of unknown sample if complied with other spectroscopic techniques. small amount of sampling material needed.	pH indicators: limited measurement precision. Uranyl-Acetate Treatment: requires the use of a UV light source to fluoresce the gel in field analysis where bright sunlight may be difficult to adjust viewing of the concrete under UV light uranyl ion is nonspecific, will associate with other cations in concrete leading to false positives concrete exposed to uranyl acetate is contaminated and must be disposed with specific procedures. Half-cell potentials method: not enough accurate difficult to repeat. Electrical resistivity tomography: requires knowledge on the computational and numerical methods. Infrared Spectroscopy: requires very good expierience in interpretation of the IR-spectra requires training on the use of IR-spectrometer not easy to perform requires expensive equipment
Quantitative chemical methods	Destructive	Bridge Viaduct	Composite Technical ceramic Concrete Biomolecules Polymer Reinforced Concrete Nanomaterials	Spalling Displacement Cracks Obstruction and impeding Debonding Loss of section	Quantitatively assess the rate of degradation	Potentiometric titration: can be performed even in the presence of a small amount of solute whose concentration is to be determined. Chloride Diffusion Test/ Ions migration in electrical field fast and effective method to determine the corrosion resistance of reinforced concrete against chloride. Galvanostatic pulse technique rapid evaluation. Argentometric titration very clear colour change at the end point of titration feasible to automate the process does not require specialized chemical knowledge. provides fast and precise result of the analysis Gravimetric method instrumental error is usually excluded does not require a series of standards for calculation. Ion chromatography accurate quantitative analysis identification and quantification of low concentrations of ions in the sample low maintenance costs and long-life of the apparatus used.	Potentiometric titration variation in electrolyte pH alters the result of titration electrolyte used in the reaction must be freshly prepared. Chloride Diffusion Test/ Ions migration in electrical field simple to operate. Galvanostatic pulse technique not possible to distinct between passive and actively corroding rebars. Argentometric titration requires practice to achieve effective results high background ionic level leads to errors. Gravimetric method: time consuming small mistake during the measurement may affect the final result. Ion chromatography only ions concentrations can be determined - complete salt-phases are determined by deduction
Radiological and nuclear methods	Non-destructive	Bridge Tunnel	Steel Composite Technical ceramic Wood Concrete Metal Polymer Reinforced Concrete	Displacement Cracks Deformation Delamination Rupture Debonding Loss of section Deteriorated mortar joints	Radiological methods are very popular for the non-destructive determination of defects, which are not visible to the naked eye in various types of structures	Computed X-ray/Gamma Tomography: dimensionally accurate analysis vertical and horizontal overview of the specimen no interference in the structure of the investigated object analysis of the shape of a defect easily accessible source of radiation. Neutron Radiography: possibility of imaging light elements. Nuclear Magnetic Resonance Spectroscopy: very accurate and detailed technique advanced NMR techniques use portable magnets that are applied to the object of interest.	Computed X-ray/Gamma Tomography: slow in case of use of X-ray radiation expensive for high power sources limited resolution. Neutron Radiography: expensive for high power sources. Nuclear Magnetic Resonance Spectroscopy: limited availability of the equipment high cost of tests difficult to operate without training equipment sensitive to environmental condition difficult calibration process.
Satellite remote sensing	Non-destructive	Bridge Tunnel Viaduct Building	Environment in general	Displacement Cracks Deformation Crushing Rupture Obstruction and impeding Debonding Holes	Collecting information about the object to be measured without making physical contact with it, in contrast to on-site observation. The use of satellite images for monitoring in the different types of infrastructures (example bridges) responds to two great advantages, the great coverage that is achieved in a single analysis and the possibility of recovering historical data, through old images.	Wide geographical and temporal coverage of the study area. Access to free information depends on the resolution you want to reach. Possibility, depending on the satellite employee, to obtain images under any climatic and geographical conditions and therefore high accessibility of information. Easy to complement or combine with other on-site techniques.	High-resolution images often come at a high price. The satellite images require a large storage capacity, as well as, to process them a great demand for computational performance. Need for experts for its use and interpretation. Depending on the type of satellite image and weather conditions, certain images may not be valid for use.
Surface measurements	Destructive	Bridge Tunnel Viaduct	Steel Rock Mortar Composite Concrete Sand Paper	Displacement Cracks Deformation Tensioning force deficiency Rupture Reinforment bar failure and bending Debonding Holes Loss of section	Bridge infrastructure monitoring technologies are crucial for predicting the effects of the damages and preventing potential accidents. The advantages of the multi-scale data collection cannot be disregarded for future infrastructure maintenance purposes, especially the possibility of real-time data storage, remote control of facilities from different locations, and enabling and sharing research results on a large scale. Surface measurements can be used on concrete samples or concrete structures directly on the facility.	Schmidt Hammer test: rapid testing inexpensive equipment. Windsor probe test: can be used as substitute of core tests light, standard and high-weight concrete strength can be tested high-precision fast and economical no accidental discharge not complicated maintenance. Pull-out test: good performance on new and old structures easy to install.	Schmidt Hammer test: estimation of the values only. can generate misleading results. Windsor probe test: leaves holes in concrete, where the probe penetrated damaged area has to be repaired usually can cause minor cracking. Pull-out test: destructive for the structure does not measure the interior strength of the concrete. large number of tests needed in different parts of the construction for accurate results.
Water penetration test - Permeability test	Destructive	Bridge Tunnel Building	Composite Wood Concrete Polymer Reinforced Concrete	Displacement Cracks Deformation Wire breaks Tensioning force deficiency Rupture Holes Loss of section	The main objective of the water penetration test in bridges or tunnels diagnostics is the determination of resistance or durability of concrete extracted from elements of structure exposed to the water flow.	Method can be performed with use of apparatus for testing water permeability with automatic control, which allows testing several samples simultaneously. Possibility of automatic testing in different research cycles as well as pressure reading directly from the pressure gauge, automatic water supply simplifies the procedures.	Guidelines for performance of test do not specify precise age of the sample at which the test should begin, nor the cut-off age of concrete that can be tested. This fact indicates on the possibility of different result for this property.
Water resistance - Absorption test	Destructive	Bridge Tunnel Viaduct	Concrete Polymer Aggregate Brick Paper	Spalling Cracks	Water resistance measurement test is used as a characterization of durability of concrete elements and durability of the surface protections.	simple to perform no specific qualifications needed for the operator. can be performed on-site and in laboratory	does not account for any type of reactive process that ties up water assumes that all the weight gain is due to water short duration of submersion compared to what might happen in long term conditions.
Weight In Motion systems (WIM)	Non-destructive	Bridge Tunnel Viaduct	Steel Concrete	Overloading	Weight in Motion (WIM) systems are utilized for traffic data collection and prevention of the overload of the structures	Automated non-stop traffic data collection Optimized infrastructure and maintenance planning Tracking of special transports Reliable calculation of remaining bridge lifetime: Reduced risk: early detection and continuous monitoring of critical structures Longer bridge lifetimes: overloaded vehicles are prevented from crossing the bridge Improved traffic safety Structural health monitoring: monitoring changes in a bridge’s structural behavior - faults are detected at an early stage	Lack of standardization Costs of the equipment Costs of the maintenance of the system Legal issues Depending on the systems – problems generated with the closing of the traffic flow

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