How to Set Up an AMTS Monitoring Network in 7 Steps

Manual survey rounds can’t keep pace with the real-time displacement and deformation data that modern construction and infrastructure projects demand. An automated motorized total station (AMTS) monitoring network solves this by running continuous, unattended measurement cycles across active surveying point on site with no manually operated equipment required.

This guide covers the 7 steps in the process to plan, install, and activate an AMTS monitoring network that produces reliable, sub-millimeter-level data.

1. Define Monitoring Objectives and Project Requirements

The monitoring objectives for a project set the direction for every network design decision that follows. Before selecting equipment or placing a single prism on site, the team needs to define what movements to measure, which infrastructure to monitor, and what tolerances the construction spec demands. These specific requirements play a key role in shaping the number and position of AMTS units, prism density, measurement frequency, and alert configurations.

Regulatory or contractual trigger levels add another layer. They tie measurement data directly to performance standards that govern when construction activity must pause or when remedial/corrective action is required. Typical project types:

• Deep excavations adjacent to occupied buildings
• Active tunneling zones
• Vehicle and rail bridges 
• Dams and embankments
• Heavy freight and commuter rail lines.

A clear grasp of these parameters is the most important first step in the process.

What Monitoring Parameters Does the Project Require?

Settlement monitoring tracks vertical displacement at foundation level and ground surface. Each parameter dictates different prism placement and AMTS line-of-sight requirements:

• Settlement: vertical displacement at foundations and ground surface
• Lateral displacement: horizontal movement in retaining walls, sheet piles, and excavation faces
• Convergence: tunnel profiles or structural openings where multi-directional movement needs precision tracking, demanding denser prism spacing and shorter observation distances

How Do Accuracy Specifications Shape AMTS Network Design?

The project’s accuracy specifications must drive instrument selection from the start.

• Half-second AMTS instruments: angular precision of 0.5″, distance accuracy of 0.5 mm + 1 ppm
• Trigger levels from the geotechnical management plan define control tolerances
• The instruments’ measurement uncertainty must sit well below the trigger threshold to detect movement reliably

With objectives defined and accuracy targets set, the next decision is how to arrange the AMTS units and reference prisms in space.

2. Design the AMTS Network Geometry

Network geometry is the single most significant factor in AMTS measurement quality. The spatial arrangement you configure for each automated total station and its reference prisms determines whether the system can deliver accurate, repeatable coordinates across the full surveying network. Getting this right at the design stage prevents problems that no amount of software processing can fix.

Key geometry rules:

• Minimum 3 reference prisms per AMTS unit, positioned at roughly 120-degree intervals. Typically we install many more than 3 to provide a more stable monitoring system, in case some control points are damaged or sightlines are blocked.
• AMTS position: where there is maximal line of sight to control and monitoring points, ideally in a protected location or otherwise installed that theft is not possible
• Reference prisms: outside the zone of influence, on stable structures unaffected by construction-induced ground movement
• Distance rule: each reference must be farther from the instruments than the farthest monitoring prism, anchoring the coordinate system at the widest possible baseline
• Slope distance: accuracy degrades as distance increases, so minimizing the line-of-sight range between the AMTS and its targets is a primary design objective

For multi-station configurations, overlapping reference prisms between adjacent AMTS units allow least-squares adjustment across the full network, tying all observations into a single coordinate frame.

What Is the Ideal Reference Prism Layout for an AMTS Network?

Configure a minimum of 6 reference prisms per AMTS unit, spaced at as evenly as possible  around the AMTS. Each reference must be rigidly attached to a stable, undisturbed structure outside the zone of influence, and farther from the AMTS than the farthest monitoring prism. No amount of post-processing can compensate for poor reference geometry. Proper angular separation between reference prisms is the most important measurement quality control in the network.

How Many AMTS Units Does the Monitoring Network Need?

The number of AMTS units depends on 3 factors:

• Line-of-sight availability: buildings, equipment, or terrain blocking sight lines
• Monitoring point count: more points than one unit can cycle through at the required frequency
• Reading frequency: faster reading frequencies may require more AMTS to be deployed. A single system can handle most compact construction sites where all prisms remain visible from one position. When any of these factors apply, multiple AMTS units work together in a multi-station configuration, sharing common reference prisms so that least-squares adjustment tools can tie all observations into a unified coordinate frame.

With the network geometry locked in, the next step is installing the reference prisms that anchor the coordinate system.

3. Install Reference Prisms Outside the Zone of Influence

Reference prisms anchor the entire coordinate system, so where and how they’re mounted is one of the most important decisions in the installation process. Every reference must sit on a structure or foundation outside the zone of influence: the area surrounding the construction site where ground movement from excavation, loading, or vibration has no measurable effect.

Common mounting options:

• • Concrete piers: resist settlement over full project duration
  • Deep-driven steel posts: stable against lateral shift
  • Stable building facades: readily available on urban sites
  • Introduced objects: on sites without stable reference locations, they can be created. For example, a reference prism could be attached to a driven post or concrete block.

Each AMTS unit should have at least 6 reference prisms. If one prism is temporarily obstructed by equipment or disturbed by site activity, the remaining instruments keep the survey solution stable and allow the network to continue operating. At least one (but ideally all) references must be farther from the AMTS than the farthest monitoring prism, which gives the least-squares adjustment a strong geometric baseline to work from.

Stable mounting alone isn’t enough. Reference prisms also need regular control checks against independent survey points to confirm they haven’t shifted. If a reference moves undetected, every coordinate the AMTS computes from that point inherits the error, so periodic verification is a key part of the quality assurance process.

With the reference network secured, the focus shifts to installing monitoring prisms on the structures being tracked.

4. Install Monitoring Prisms on Target Structures

Monitoring prisms are fixed directly to the structures or ground surfaces the AMTS network is set up to monitor. The prism type depends on the application:

• L-bar prisms: most widely used, secured to retaining walls, sheet piles, and building facades with specialized mounting tools and brackets
• Wall brackets: columns and vertical surfaces
• Road prisms: settlement tracking on paved surfaces
• Rail clip prisms: track infrastructure for railway geometry measurement

Prism spacing is driven by the structure type and the movement patterns the project needs to capture. Tighter spacing delivers higher-resolution data collection across areas where displacement varies over short distances, like excavation faces or tunnel linings. Wider spacing works for uniform structures where movement tends to be consistent across longer spans.

Orientation is just as important as placement. Each prism must face the AMTS with a clear, unobstructed line of sight at every measurement cycle, because even minor angular misalignment reduces the return signal strength and degrades coordinate precision.

On active construction sites, prism placement needs to account for planned equipment movements and temporary obstructions that could block sightlines as work progresses. Verifying line-of-sight access from every AMTS position before finalizing prism locations saves time and prevents gaps in the accurate displacement record.

Once all monitoring prisms are in position, the next step is mounting the AMTS units themselves.

5. Mount and Position the AMTS Units

Each automated motorized total station mounts on a tower, wall bracket, or purpose-built platform positioned for unobstructed sight lines to every assigned prism. The AMTS must have a direct line of sight to all reference and monitoring prisms from its fixed position, so the mounting location needs to be finalized only after confirming visibility to every target on site. Even a single blocked sight line means a gap in the displacement record for that prism until the obstruction clears.

Stable mounting is the most important performance factor at the instrument level. Vibration from nearby construction equipment, thermal expansion of the mounting structure, or settlement/rotation of the platform all degrade the accurate coordinate output the AMTS produces. Steel towers with concrete foundations or rigid wall brackets on stable structures are the standard options. The mounting must be stiff enough that wind loads and temperature swings don’t shift the instruments between observation cycles.

Power and environmental protection complete the installation:

• AC mains: preferred option where site infrastructure allows
• Solar panels with battery backup: for remote or temporary sites that lack grid access
• Weatherproof enclosures: shield the instrument from rain, dust, and temperature extremes

With the AMTS units mounted and powered, the next step is connecting the data acquisition and communication systems that move observation data off-site.

6. Configure Data Acquisition and Communication Systems

The on-site controller is the central hub of the data acquisition system, scheduling measurement cycles, directing AMTS observations, and transmitting recorded data to the processing server. Communication links use cellular modems, Wi-Fi bridges, or hardwired Ethernet connections depending on site infrastructure and access requirements. The controller manages the full observation sequence: target acquisition, angular and distance measurement, data collection, and transmission, running the process automatically without manual intervention.

The data flow follows a clear path:

• AMTS captures angular and distance measurements
• Controller logs data locally and transmits to the processing server
• Cloud software runs quality control checks, least-squares adjustments, and flags outliers
• Web platform publishes displacement trends, time-serlive plan views, alert functionality, automated reports, and project journal

Project teams work with all monitoring information through an AMTS monitoring data platform that consolidates data collection, processing, and alerts into a single web interface.

Measurement frequency is one of the most important configuration decisions:

• • Active excavation: hourly observation cycles to capture rapid ground movement
  • Long-term structural/dam monitoring: 4-6 hour intervals, reducing data volume while detecting gradual trends The team can configure observation frequency remotely at any time using the platform’s management console, tightening or relaxing the cycle as construction phases change and performance thresholds shift.
  • Rail monitoring: Hourly observation intervals to capture quick changes in track geometry

With data flowing from the field to the processing platform, the final step is calibrating the network and activating continuous monitoring.

7. Calibrate, Validate, and Activate Continuous AMTS Monitoring

Before activating continuous monitoring, run a week or two week long baseline measurement period to establish reference coordinates and validate the network’s repeatability. Compare results from consecutive cycles against each other and against known control points from independent survey data. If the coordinate differences between cycles fall within the project’s precision thresholds, the network is producing accurate, stable output. If they don’t, revisit prism alignment, reference geometry, or atmospheric correction settings before proceeding.

Once the baseline is validated, set alert thresholds aligned with the project’s trigger levels. The monitoring platform flags any measurement that exceeds a threshold, sending immediate, automated notifications to the project team via email and text message. This process runs continuously: the AMTS cycles through its prism list on the configured schedule, the server applies least-squares adjustments and quality checks to each data set, and the web dashboard updates displacement time-series graphs in near real-time.

Ongoing performance depends on regular maintenance:

• Periodic prism cleaning
• Instrument servicing
• Reference coordinate verification

The network operates unattended between maintenance visits, but the automated alert system catches anomalies the moment they appear in the data, so the team can intervene before data gaps start to appear in the monitoring record.

The reliability of this entire workflow depends on the hardware and software components that make up the AMTS monitoring network and the quality of the installation.

What Are the Components of an AMTS Monitoring Network?

A complete AMTS monitoring network relies on 4 main components that work together to deliver continuous, automated displacement data.

This section provides a component-level breakdown for teams that need a clear grasp of the equipment before starting the setup or evaluating a monitoring proposal. The tools and management systems described below correspond directly to the 7 installation steps covered above.

Survey Prisms in an AMTS Monitoring Network

Survey prisms are the passive optical targets the AMTS instruments use to take each measurement. Monitoring prisms are fixed to the construction structures or ground surfaces being tracked, while reference prisms are mounted on stable foundations outside the zone of influence to anchor the coordinate system. Both types are used with specialized mounting hardware (L-bars, wall brackets, road plates, rail clips) selected to match the site conditions and the surveying application.

Automated Motorized Total Station Instruments

An automated motorized total station is a robotic surveying instrument with motorized drives that lock onto prism targets, measure angles and distances, and record coordinates without manual input. Half-second AMTS equipment achieves angular precision of 0.5″ and distance accuracy of 0.5 mm + 1 ppm, which delivers the accurate, sub-millimeter-level data that high-specification monitoring projects require.

Controllers and Communication Hardware

The on-site controller is a ruggedized computing system that runs the observation schedule, directs the AMTS through its prism list, and logs all data locally before transmitting it to the processing server. Communication options include cellular modems, Wi-Fi bridges, and hardwired Ethernet, selected based on site access and network reliability requirements. Field teams configure the controller’s software remotely using the monitoring platform’s web interface, adjusting observation schedules and communication settings as project conditions change.

Processing Server and Monitoring Software Platform

The processing server receives raw data from the field controllers, applies least-squares network adjustments, and runs automated quality checks to process every observation cycle. Cloud-based monitoring software then publishes the results to a web-based management platform where project teams access displacement graphs, site maps, and real-time alert dashboards. This system consolidates all data collection, information storage, and performance reporting into a single interface, reducing the time between field measurement and actionable project insight to minutes.

These 4 components form the foundation of every AMTS monitoring network, from single-station setups to multi-station deployments spanning entire construction corridors.

Get Expert AMTS Monitoring Network Support From Sixense

Every construction project that relies on AMTS monitoring needs precision hardware, sound network geometry, and continuous automated performance management to work as designed. Sixense provides end-to-end AMTS monitoring through its Cyclops platform, which allows project teams to monitor displacement around the clock and reduces the time between network design and validated, live data in the field. Contact the Sixense team to discuss your project requirements and receive a monitoring network proposal.

Frequently Asked Questions About AMTS Monitoring Networks

What Accuracy Can an AMTS Monitoring Network Achieve?

Half-second AMTS instruments achieve angular accuracy of 0.5″ and distance accuracy of 0.5 mm + 1 ppm. Least-squares processing across multiple observation cycles improves the network-level precision to sub-millimeter levels for typical monitoring distances.

How Many Prisms Can a Single AMTS Unit Monitor?

A single AMTS total station can typically monitor 20 to 80+ prisms per observation cycle, depending on line-of-sight availability and the required measurement frequency. More prisms extend the cycle duration, so networks with high prism counts and tight time requirements may need multiple AMTS units in a multi-station configuration.

Does an AMTS Monitoring Network Require On-Site Personnel?

AMTS networks operate unattended around the clock, running automated observation cycles and transmitting data to the processing server without on-site personnel. Periodic maintenance visits for prism cleaning and instrument checks keep the network performing at specification, but day-to-day monitoring runs remotely, and is highly economical compared to fully-manual surveys

How Does Weather Affect AMTS Monitoring Network Performance?

Rain, fog, and heavy snow can obstruct the line of sight between the AMTS and its prisms, temporarily reducing measurement quality or blocking individual observation cycles. Redundant measurement cycles and built-in atmospheric correction sensors mitigate weather disruptions, so brief events rarely produce gaps in the monitoring record.

How Often Does an AMTS Monitoring Network Need Maintenance?

Routine maintenance includes periodic prism cleaning, instrument servicing, and reference coordinate verification to keep measurement accuracy at specification. The network operates unattended between maintenance visits, and the automated alert system flags any data anomalies that may signal a hardware or alignment issue. Typically a site visit is needed every 1-3 months.