**2. Importance and relevance of the technical content**

Monitoring of situations and territories with hydro-geological risk represent an institutional task of the Public Administrations. Therefore, in some areas, it becomes necessary to achieve systems for real-time survey, which are able to record the alarm signs of a potential risk for the population. An early-warning system provides, also, the foundation for an effective risk mitigation plan, given the uncertainties related to the mathematical prediction of the natural phenomena and the strong public demand for protection against natural hazards.

The World Bank promotes a proactive and strategic approach to managing natural hazard risk, by taking into account a comprehensive framework, based on the following five pillars:

**Risk assessment -** includes application of the hazard, exposure, vulnerability, and loss analyses and provides projections of the average annual expected loss and the probable maximum loss from a single catastrophic event;

**Emergency preparedness.** Citizens and government agencies need to be prepared for breakdowns în essential services, to develop plans for contingencies, and to implement the plans. They should be encouraged to make resources available for facilities and equipment, they need to provide emergency personnel, they need training, sponsor exercises, and get information available for the public;

**Investments in risk mitigation.** This may include inexpensive investments in increasing institutional capacity, strengthen enforcement of building codes, provide training, and involve communities, including mapping, monitoring and warning systems. As investments in physical infrastructure (flood protection, landslides prevention and retrofitting of housing and/or public buildings for seismic resistance) are very expensive, the selection of the most suitable of them should be carried out by applying cost-benefit or costeffectiveness analysis;

**Institutional capacity building.** The efficiency and effectiveness of a comprehensive hazard risk management system depends on the knowledge, awareness, and capacity of the stakeholders involved. For that purpose, the following aspects are recommended:


It is also important to integrate hazard risk management into the economic development process. Emergency planning and risk mitigation need to be an integral part of the rural and urban development process, with the participation of all the stakeholders.

**Develop a catastrophe risk financing strategy.** Countries need to develop and introduce targeted risk financing strategies for dealing with catastrophic events that can have a severe impact on their economies. The strategy would address the funding gap caused by the need to recover economic losses and meet social obligations and other responsibilities, following a catastrophic event. Developing a risk financing strategy is particularly important for countries exposed to catastrophic earthquakes.

Therefore, the Regional Public Administrations from a country, which has more or less accentuated risk for the natural disasters, may have at their disposal the possibility to verify, at pre-established time intervals, the real state of the geological formations or of the building, which is suspected to be in danger.

The main application of the MSM equipment presented here, is the estimation and the alerting in due time regarding the risk of great proportion accidents, by break down of civil constructions due to some natural causes, such as landslides and floods, in areas with high risk of accidents.

The final result will be the achievement of a Geographic Informational System (GIS), which will have to integrate all the information and the all types of data, which are needed for the natural disasters management, from the prognosis to the post-factum measurements. Moreover, besides the hazard maps which must be elaborated for the all regions of the respective country, the local authorities must, also, draw up risk maps which refer to the most exposed areas to the natural calamities.

### **3. State of the art**

154 Cartography – A Tool for Spatial Analysis

to terrain sliding from natural or human causes. As opposed to the systems which achieve in static regime the stability monitoring of the constructions by using some precision optical systems or GPS equipments with differential regime functioning but to which the follower receiver is attached in a fixed montage on the surveyed construction, the proposed mobile monitoring system permits that the measurements be rapidly performed, at a preset time interval, with a reduced cost on a multitude of objectives and with a minimum delay between the moment of some defection apparition and the moment of its identification and alarming.

Monitoring of situations and territories with hydro-geological risk represent an institutional task of the Public Administrations. Therefore, in some areas, it becomes necessary to achieve systems for real-time survey, which are able to record the alarm signs of a potential risk for the population. An early-warning system provides, also, the foundation for an effective risk mitigation plan, given the uncertainties related to the mathematical prediction of the natural

The World Bank promotes a proactive and strategic approach to managing natural hazard risk, by taking into account a comprehensive framework, based on the following five pillars: **Risk assessment -** includes application of the hazard, exposure, vulnerability, and loss analyses and provides projections of the average annual expected loss and the probable

**Emergency preparedness.** Citizens and government agencies need to be prepared for breakdowns în essential services, to develop plans for contingencies, and to implement the plans. They should be encouraged to make resources available for facilities and equipment, they need to provide emergency personnel, they need training, sponsor exercises, and get

**Investments in risk mitigation.** This may include inexpensive investments in increasing institutional capacity, strengthen enforcement of building codes, provide training, and involve communities, including mapping, monitoring and warning systems. As investments in physical infrastructure (flood protection, landslides prevention and retrofitting of housing and/or public buildings for seismic resistance) are very expensive, the selection of the most suitable of them should be carried out by applying cost-benefit or cost-

**Institutional capacity building.** The efficiency and effectiveness of a comprehensive hazard risk management system depends on the knowledge, awareness, and capacity of the

stakeholders involved. For that purpose, the following aspects are recommended:

 to create decentralized emergency management systems; to ensure community involvement and participation;

to provide training, education, and knowledge sharing.

to develop an efficient legal framework, and

phenomena and the strong public demand for protection against natural hazards.

**2. Importance and relevance of the technical content** 

maximum loss from a single catastrophic event;

information available for the public;

effectiveness analysis;

Usually, the measurement of superficial displacement is the simplest way to observe the history of a landslide and to analyze the kinematics of the movement, so the investigation of the terrains sliding movements permits, also, the detection of possible precursor elements of the mass movements.

#### **3.1. Existing fixed mapping equipments**

In the past, a various surveying techniques were used to detect the superficial movements of unstable area. For examples, tapes and wire devices were used to measure changes in distance, between terrain points or crack walls. Levels, theodolites, Electronic Distance Measurement (EDM), and total station measurements provide both the coordinates and changes of target, control points and landslide features. In addition, aerial or terrestrial photogrammetry provides point coordinates, contour maps and cross-section of the landslides.

#### *3.1.1. Leica Smart Station (Scott A., 2006)*

A classical example of such optical measurement equipment for observing different targets with displacement probability is the "Leica Smart Station", a Total Station with integrated GPS offered on the market by the "Leica Geosystems AG" company. The introduction of SydNET, a network of Continuously Operating Reference Station (CORS), allows surveyors to perform Differential GPS without having to purchase a reference receiver. For distances of up to tens of kilometres away from the network reference stations, centimetre accuracy can be achieved, with the RTK-GPS Network.

GPS Positioning of Some Objectives Which are Situated

at Great Distances from the Roads by Means of a "Mobile Slide Monitor – MSM" 157

**Figure 1.** Fixed Satellitary Monitoring System of the Territory and Civil Infrastructures achieved by

The Field Sensor uses a single frequency GPS receiver to measure the carrier phase on the L1 GPS signal and an RF Modem for point-to-point communication with the base station via radio link. A microcontroller supervises the communication and the exchange of data

"SEPA Sistemi Elettronici Per Automazione S.p.A." from Torino (Italy).

**Figure 2.** GNSS receiver

This equipment involves the optical observation of the proposed object from different static locations of the operator, locations which are precisely determined by means of the highly performing GPS receiver. In these conditions, the determination of the geographic coordinates of a single distant objective involves multiple complex operations and in consequence, can be considered time consuming.

#### *3.1.2. SEPA's system (Caporali A., 2008)*

Another totally different technical solution for this problem, solution which aims to reduce the length of the measurement times involved by the use of the optical total stations, is represented by the "Fixed Satellitary Monitoring System of the Territory and Civil Infrastructures" (or SAMOS for short) achieved by SEPA company ("Sistemi Elettronici Per Automazione S.p.A.") from Torino (Italy).

The SEPA's system represents a solution for cost effective applications targeting the real time monitoring and diagnosis of ground deformation; for instance, landslides and the subsidence, or the infrastructure deformations affecting buildings, bridges, viaducts and dams, or even both simultaneously.

Based on measurements from a GPS L1-only carrier phase employing commercial receivers and using the basic principles of interferometric surveying, SAMOS provides continuous real-time monitoring of the area of interest, reporting the millimetric displacement of each sensor relative to a reference sensor.

Measurements are taken at a rate of 1 Hz and the processed results are updated using the same frequency. The system performance is equivalent, on short baselines up to a few km in length.

This Satellitary Monitoring System, in fact like other this kind of systems, is composed of two subsystems, namely:


For its protection this Base Station is introduced in a Waterproof box (Fig. 4).

**Figure 1.** Fixed Satellitary Monitoring System of the Territory and Civil Infrastructures achieved by "SEPA Sistemi Elettronici Per Automazione S.p.A." from Torino (Italy).

#### **Figure 2.** GNSS receiver

156 Cartography – A Tool for Spatial Analysis

*3.1.1. Leica Smart Station (Scott A., 2006)* 

can be achieved, with the RTK-GPS Network.

consequence, can be considered time consuming.

*3.1.2. SEPA's system (Caporali A., 2008)* 

Automazione S.p.A.") from Torino (Italy).

dams, or even both simultaneously.

sensor relative to a reference sensor.

two subsystems, namely:

sensors.

length.

A classical example of such optical measurement equipment for observing different targets with displacement probability is the "Leica Smart Station", a Total Station with integrated GPS offered on the market by the "Leica Geosystems AG" company. The introduction of SydNET, a network of Continuously Operating Reference Station (CORS), allows surveyors to perform Differential GPS without having to purchase a reference receiver. For distances of up to tens of kilometres away from the network reference stations, centimetre accuracy

This equipment involves the optical observation of the proposed object from different static locations of the operator, locations which are precisely determined by means of the highly performing GPS receiver. In these conditions, the determination of the geographic coordinates of a single distant objective involves multiple complex operations and in

Another totally different technical solution for this problem, solution which aims to reduce the length of the measurement times involved by the use of the optical total stations, is represented by the "Fixed Satellitary Monitoring System of the Territory and Civil Infrastructures" (or SAMOS for short) achieved by SEPA company ("Sistemi Elettronici Per

The SEPA's system represents a solution for cost effective applications targeting the real time monitoring and diagnosis of ground deformation; for instance, landslides and the subsidence, or the infrastructure deformations affecting buildings, bridges, viaducts and

Based on measurements from a GPS L1-only carrier phase employing commercial receivers and using the basic principles of interferometric surveying, SAMOS provides continuous real-time monitoring of the area of interest, reporting the millimetric displacement of each

Measurements are taken at a rate of 1 Hz and the processed results are updated using the same frequency. The system performance is equivalent, on short baselines up to a few km in

This Satellitary Monitoring System, in fact like other this kind of systems, is composed of



field sensors are continuously relayed by means of a radio connection to

For its protection this Base Station is introduced in a Waterproof box (Fig. 4).

The Field Sensor uses a single frequency GPS receiver to measure the carrier phase on the L1 GPS signal and an RF Modem for point-to-point communication with the base station via radio link. A microcontroller supervises the communication and the exchange of data

between the GPS receiver and the radio modem, and in addition, it supplies diagnostic data related to the sensor itself.

GPS Positioning of Some Objectives Which are Situated

at Great Distances from the Roads by Means of a "Mobile Slide Monitor – MSM" 159

displacements of each antenna with respect to the reference antenna, using diagrams and tables. The GUI can be tailored to the customer's requirements, and it will alert the operator

The main disadvantage of the SEPA types fixed systems is that this equipment must be mounted in a fixed position on every point of interest, meaning that for an objective or an area suspected to present landslides, a great number of equipments of this kind is necessary,

Taking account of the newest improvements of the GNSS systems regarding the real-time positioning accuracy, (A. Stoica et al., 2008), the authors of this chapter present the achievement of a mobile equipment for the monitoring of the field stability as opposed to the most used in present, static optical total stations, "Leica" or "SEPA" type systems, which are based on GPS receivers with differential regime functioning but which are fixed

But one must specify that also for this mobile alternative, which is proposed here for the monitoring of some objective position, there are various mobile equipments for mapping and, respectively, for monitoring, introduced on international level, equipments which are

The Mobile Mapping Equipment "GPSVisionTM" (fig. 5) achieved by the "LAMBDA TECH International" company from Fort Wayne (USA), which is equipped with a positioning module composed of a GPS receiver with double frequency, an Inertial Navigation System (INS) and a linear Distance of running Measuring Instrument (DMI), in combination with four digital video cameras of high resolution. The digital video cameras are mounted above the vehicle and they can be oriented forward, to each side or backward in correspondence with the application needs, so that due to the fact that the video cameras pairs see, at a certain moment, the same field area from different positions, by using some triangulation algorithms, it is

 The images are taken according to an operator-defined distance interval to provide full coverage of the route and its surroundings. By applying a sophisticated photogrammetric triangulation technology, any point that appears in any set of two images can be located in a global coordinate system during digitization with Lambda

 Stereo imaging allows for determining absolute positions of features such as signs in latitude and longitude to sub-meter accuracy and it also allows very accurate relative measurements of all visible roadside attributes, such as the width, height and offset of a

*3.2.1. "GPSVisionTM" achieved by the "LAMBDA TECH International" company* 

possible to calculate the locations relative to the lab vehicle of the sighted targets.

when preset thresholds are exceeded.

and, in consequence, high total costs.

mounted on the surveyed objectives.

described in the following subsections.

The main characteristics of the system are:

Tech's Feature Extraction software;

*(Guangping He, 1996)* 

**3.2. Existing mobile mapping equipments** 

**Figure 4.** Waterproof box of the Base Station

It is also important to mention that, for this SAMOS system, it is necessary that, on the surveyed objectives, to be assured permanent electrical energy supplies (which can be constituted from photovoltaic panels or, if this is available, from the mains power supply of the area). In both cases, a backup battery is included. Moreover, we must notice that the receivers and the system GPS components remains in field in the majority of cases, without any surveillance from the operators.

The Base Station includes the network controller, used to receive the GPS data collected via radio links from sensors deployed in the field, and a computer running the software to process the data and display the results in real-time. The raw measurement data as well as the results are stored in a database for possible further processing, if required, or simply archiving. (Caporali A., 2008)

#### *3.1.3. Conclusions referring to the fixed monitoring systems*

In addition to collecting the measurement data, the base station can retrieve status information from the sensors, such as the accumulator supply voltage, RF link signal strength and temperature.

The Graphic User Interface (GUI) shows the real-time status of the network (satellites available and being tracked, nominal antenna locations and network geometry, status of each sensor) and the results of the data analysis as northing, easting and vertical displacements of each antenna with respect to the reference antenna, using diagrams and tables. The GUI can be tailored to the customer's requirements, and it will alert the operator when preset thresholds are exceeded.

The main disadvantage of the SEPA types fixed systems is that this equipment must be mounted in a fixed position on every point of interest, meaning that for an objective or an area suspected to present landslides, a great number of equipments of this kind is necessary, and, in consequence, high total costs.

Taking account of the newest improvements of the GNSS systems regarding the real-time positioning accuracy, (A. Stoica et al., 2008), the authors of this chapter present the achievement of a mobile equipment for the monitoring of the field stability as opposed to the most used in present, static optical total stations, "Leica" or "SEPA" type systems, which are based on GPS receivers with differential regime functioning but which are fixed mounted on the surveyed objectives.

## **3.2. Existing mobile mapping equipments**

158 Cartography – A Tool for Spatial Analysis

related to the sensor itself.

**Figure 3.** Base station

**Figure 4.** Waterproof box of the Base Station

any surveillance from the operators.

archiving. (Caporali A., 2008)

strength and temperature.

*3.1.3. Conclusions referring to the fixed monitoring systems* 

between the GPS receiver and the radio modem, and in addition, it supplies diagnostic data

It is also important to mention that, for this SAMOS system, it is necessary that, on the surveyed objectives, to be assured permanent electrical energy supplies (which can be constituted from photovoltaic panels or, if this is available, from the mains power supply of the area). In both cases, a backup battery is included. Moreover, we must notice that the receivers and the system GPS components remains in field in the majority of cases, without

The Base Station includes the network controller, used to receive the GPS data collected via radio links from sensors deployed in the field, and a computer running the software to process the data and display the results in real-time. The raw measurement data as well as the results are stored in a database for possible further processing, if required, or simply

In addition to collecting the measurement data, the base station can retrieve status information from the sensors, such as the accumulator supply voltage, RF link signal

The Graphic User Interface (GUI) shows the real-time status of the network (satellites available and being tracked, nominal antenna locations and network geometry, status of each sensor) and the results of the data analysis as northing, easting and vertical But one must specify that also for this mobile alternative, which is proposed here for the monitoring of some objective position, there are various mobile equipments for mapping and, respectively, for monitoring, introduced on international level, equipments which are described in the following subsections.
