Emlid Reach in Construction QA: RS3 field workflows for control, check shots, and as-builts

Construction teams move fast, and the decisions they make depend on field data they can trust. Layout crews establish control early, but quality checks, as-builts, and progress verification often outpace the availability of survey resources. When a project’s schedule tightens or multiple subcontractors are working in parallel, waiting for a surveyor to confirm a few key points can slow production and raise the risk of rework. Tools exist to verify work more frequently, yet many of them remain locked behind specialized equipment, steep learning curves, and workflows that only a handful of people on the project can operate.

This is where Emlid Reach RS3 changes the dynamic. It brings survey-grade GNSS accuracy into field-ready workflows that foremen, project engineers, and VDC teams can use confidently without replacing total stations already in place. Instead, it gives teams a practical way to verify control, collect as-builts, check grades, and support drone mapping workflows with consistent, repeatable data.

The RS3 does this through a combination of multi-band GNSS performance, a factory-calibrated IMU for tilt compensation, and software tools that synchronize field measurements with office models in real time. It gives teams the ability to validate work when questions arise and to document site conditions without waiting for a specialist. That leads to more autonomy on the ground and fewer bottlenecks around survey tasks that directly affect schedule, excavation, concrete placement, and utility installation.

In the next section we'll look at where the RS3 fits alongside the instruments construction teams already rely on, and how it complements the tools you use to keep a project moving.

Where the Reach RS3 Fits in a Construction Tech Stack

The RS3 fills the high-value GNSS gap. It gives you fast horizontal and elevation checks on a large site without pulling a survey crew off critical layout. It is built for tasks where mobility and repeatability matter more than sub-millimeter precision.

Typical use cases on active projects include:

• Check shots on control and key points

• As-built collection throughout the life of the project

• Verifying subcontractor work against the model or plans

• Daily grade checks on sitework packages

• Establishing and maintaining local site control

For large GCs, it is a supplement. Project engineers, foremen, and superintendents can run an RS3 kit for verification and documentation while survey stays focused on high-risk layout and critical control.

For small and mid-size contractors, it is a primary GNSS tool. One RS3 kit can handle site control, QC checks, and support for drone mapping without the cost or complexity of a full survey department.

Rover, base, and software stay in one ecosystem. The RS3 can work as a rover on a correction network or as a local base for drones and additional rovers. Paired with Emlid Flow in the field and Flow 360 in the office, it keeps points, linework, and surfaces consistent across crews and project stages.

Core Construction Workflows the RS3 Supports

Most contractors are not asking for more survey. They are asking for a way to check critical work without waiting in line for a crew. The RS3 fits into that by giving field teams a controlled way to verify what is happening on the ground.

At a high level, construction teams use RS3 in five core workflows:

• Check shots and daily QA

• As-built collection for underground and site features

• Verifying subcontractor work against design

• Daily grade checks in sitework

• Establishing and maintaining local site control

From there, each team builds its own playbook.

Check Shots and Daily QA

A field engineer or layout tech can walk a site with an RS3 and grab a small set of high-value check shots on slabs, utilities, and control points. The goal is simple: confirm that elevations and positions are still holding before crews commit to the next task. For example, a foreman can confirm a grade break before a morning pour instead of guessing from a tape and a benchmark.

Instead of waiting for a formal survey request to come back, the team can answer questions like:

• “Is this pad still within tolerance?”

• “Did that control point move when they reworked the area?”

As-Built Collection That Ties Back Into the Model

As soon as utilities are buried or concrete is placed, memory is no longer enough. RS3 gives the project a way to capture as-builts in the same coordinate system used by the office. Crews can collect points and linework for:

• Underground utilities and structures

• Site features like walls, curbs, and ramps

• Final locations of key assemblies

Because those points are tied to the same control as the model, VDC teams can pull the data into CAD or BIM without guesswork, offsets, or hand-drawn sketches.

Verifying Subcontractor Work with Actual Geometry

Visual inspection still matters, but on complex sites it is not sufficient. With an RS3 in hand, a GC can verify:

• Utility lines against design alignments

• Flatwork slopes against required drainage

• Pad corners and building offsets against control

This turns difficult conversations into specific ones. Instead of “this looks off,” the team is looking at measured differences from the design surface or alignment.

Daily Grade Checks in Sitework

Earthwork moves fast. Surfaces can change significantly over a single shift. RS3 gives superintendents and foremen a way to perform targeted grade checks without interrupting machine control workflows.

A short loop of elevation shots compared to the design surface answers questions like:

• “Are we approaching over-cut in this area?”

• “Is this haul road building up more material than expected?”

Small, frequent checks catch problems before they become change orders.

Establishing and Reinforcing Local Site Control

Every digital workflow depends on stable control. RS3 can:

• Work on network corrections for everyday tasks

• Serve as a base to establish or reinforce a local site coordinate system

• Provide a common reference for drones, rovers, and machine control

That consistency reduces the errors that come from mixing coordinate sources. When the drone flight, the rover checks, and the office model share the same backbone, your entire QA stack becomes more predictable.

How the RS3 Holds Accuracy in Real Construction Conditions

Accuracy on a job site is not theoretical. It depends on how well a receiver handles metal, machinery, partial sky visibility, and constant movement. The RS3 is built for those environments, and its performance comes from a mix of GNSS tracking, IMU behavior, and antenna design that holds up in situations where cheaper or older gear begins to drift.

Multi-Band GNSS Designed for Cluttered Sites

Construction sites are full of signal obstacles. Steel structures rise and fall, equipment moves constantly, and crews work around rebar, formwork, and vehicles. The RS3 tracks multiple frequency bands across all major constellations. That matters because more frequency diversity improves the receiver’s ability to reject poor signals, recover from brief blockages, and hold a stable fix as you move through varying sky conditions. Higher frequency bands help it keep a solution in tight urban environments and around buildings where single-band receivers struggle.

Multipath Rejection That Keeps Positional Drift in Check

Multipath is the kind of error that quietly ruins data. Signals bounce off steel, glass, machinery, and even the side of a concrete wall, arriving at the antenna slightly delayed. If a receiver cannot reject those reflections, the result is coordinate drift that shows up in your CAD or model as misaligned points.

The RS3 antenna and GNSS engine are designed to suppress reflected signals and prioritize high-quality satellite tracks. This stabilizes the solution on active construction sites, especially in areas near cranes, scaffolding, or parked equipment. That means fewer questionable readings and fewer “take another shot just in case” moments.

Tilt Compensation That Works Without Constant Recalibration

Tilt matters when you are working near walls, reaching across trenches, or collecting points in tight spaces. The RS3 uses a factory-calibrated IMU to provide tilt compensation that does not require repeated field calibration. As long as the pole tip stays on the point, the system adjusts for pole angle and converts the measurement to the true coordinate.

This speeds up work in practical ways:

• Checking elevations near formwork and barriers

• Verifying utilities in trenches without leaning over the edge

• Capturing points around obstructions without forcing a perfectly plumb pole

The main advantage is confidence. Tilt data that holds steady removes the second guessing that comes with less reliable IMU implementations.

Accuracy That Holds When Running as a Rover or as a Local Base

Depending on the site, teams may run RS3 on a network correction service or set it up as a dedicated base to control the full project. Both approaches work, but a local base introduces two benefits:

• A consistent, site-specific coordinate framework

• Stronger vertical control on projects where elevation tolerances are tight

Because RS3 can serve both roles, teams can switch from network RTK to local RTK as a project grows or moves into more complex phases. This flexibility keeps the receiver relevant from early grading through utilities and into later-stage verification.

Ruggedness That Holds Up Under Field Abuse

Most GNSS failures in construction are not signal failures. They are hardware failures. Units get dropped, thrown into trucks, rained on, covered in dust, and used by multiple crews. The RS3 ingress protection rating, sealed housing, and long battery life are less about specifications and more about uptime. A receiver that survives rough handling and runs an entire shift without a recharge is a receiver that actually gets used.

Together, these elements make the RS3 more than a spec sheet. They make it a stable part of a job site workflow where conditions are unpredictable, precision matters, and verification needs to keep pace with the work.

Connecting Field and Office with Emlid Flow and Flow 360

Most problems in construction QA do not start in the field or the office. They start in the handoff between them. A point gets coded differently than last week. Linework arrives in the wrong coordinate system. A field engineer takes good measurements but stores them on a device no one else can access. These gaps cost time, introduce uncertainty, and weaken trust in the project’s digital model.

Emlid Flow is built around the realities of fieldwork. Crews are busy. Weather changes. People jump between tasks. Flow keeps things simple by giving them exactly what they need and nothing they do not. Once the project is set up with the right coordinate system and coding structure, field teams open the project and get to work. 

• Stakeout workflows for points and linework

• Check shot tools with real-time deviation feedback

• Clear code libraries that match the design

• Quick access to project basemaps and layers

The result is consistent field data, even when different people collect it.

Flow 360 keeps the office side clean. As soon as a shot syncs, the VDC team can see its attributes, geometry, and photos directly in the browser. No screenshots. No missing metadata. No waiting for someone to send the file when they get back to the trailer.

Because everything is tied to the same coordinate framework, office teams can move measurements directly into:

• CAD for plan updates

• BIM for clash checks and model validation

• Drone processing workflows as ground truth

• Project archives for long-term record keeping

Multi-user workflows matter more than most teams expect. A single RS3 kit works well on smaller jobs, but large contractors benefit from letting multiple field engineers or foremen contribute to the same project dataset. Flow 360 synchronizes their work without letting naming conventions drift or project folders splinter into conflicting versions. That consistency supports a controlled QA environment where data from week twelve still aligns with data from week two.

The final piece is alignment with drone capture. Drone mapping becomes far more reliable when GCPs, checkpoints, and supplemental field verification all originate from the same system that the drone team will use to validate and correct their surfaces. Flow and Flow 360 provide that single source of truth. Instead of scattering points across PDFs, spreadsheets, and shapefiles, every measurement lives in one structured environment that feeds directly into the model the project depends on.

Flow and Flow 360 turn the RS3 from a field tool into an integrated part of the project’s digital workflow. They close the distance between crews on the ground and teams in the office, which is where construction accuracy either holds together or starts to slip.

Using the RS3 in Drone Mapping and Reality Capture Workflows

When you look at how teams are using Reach receivers in the real world, the pattern is consistent: a Reach unit defines control, a drone collects data, and GIS or CAD tools consume that data for design, QA, and reporting.

The RS3 fits into that same pattern on construction projects. Below are four concrete workflows that mirror how Emlid users are already working today, adapted to typical construction and VDC tasks.

Workflow 1: RS3 Rover for Check Shots, As-Builts, and Grade Verification

This is the daily driver workflow that supports drone work without requiring a new survey every time something changes.

Goal: Give field teams a fast way to validate surfaces, document as-built conditions, and feed reliable checkpoints back into drone and model workflows.

Steps:

• 1. Connect to corrections

  Power on the RS3 and connect it to your phone or tablet in Emlid Flow. Connect to a CORS / NTRIP service or a local base (Reach or third party) using the same coordinate system as your project.

• 2. Set up the project in Emlid Flow

  Create a new project with the correct coordinate system and vertical datum. Add layers for control, check shots, as-builts, and grade checks to keep field data organized.

• 3. Establish or verify local site control

  Use the RS3 to occupy existing control points, or set new points with RTK or static observations, depending on your accuracy requirements. Store these as Control features. These will anchor both drone models and future field checks.

• 4. Collect field data with tilt compensation

  Use the RS3 on a rover pole to collect check shots on finished surfaces and critical elevations, as-built points on utilities, edges of pavement, corners, and structures, and daily grade checks in cut and fill areas. Use tilt compensation for shots near walls, under overhangs, and around equipment where vertical pole placement is not possible.

• 5. Sync to the office through Flow 360

  Sync the project to Emlid Flow 360 so VDC and engineering teams can access it quickly. Export points and lines to CAD, BIM, or GIS as needed.

• 6. Use RS3 data as checkpoints for drone models

  When you receive a new orthomosaic or point cloud, use your RS3 check shots as independent checkpoints to validate horizontal and vertical accuracy. Flag discrepancies for rework, a new flight, or model adjustment.

Result: RS3 becomes the reference that ties ground truth, drone deliverables, and the design model together on a day-to-day basis.

Workflow 2: RS3 as a Local Base for Drone RTK Mapping

Here the RS3 acts as the on-site reference that feeds corrections to a drone with RTK capability.

Goal: Create a stable construction site coordinate framework and stream RTK corrections to the drone for consistent mapping.

Steps:

• 1. Set the RS3 on a stable point

  Mount the RS3 over a known control point, or establish a long-duration averaged point if you do not have existing control. Level the pole or tribrach and lock it down.

• 2. Configure RS3 as a base in Emlid Flow

  In Base mode, enter the antenna height and base coordinates (known or averaged). Enable corrections output via UHF / LoRa radio for compatible rovers, or via NTRIP / local caster if the drone can consume corrections over a network connection.

• 3. Bring the drone into the same reference frame

  Configure the drone RTK settings to pull corrections from the RS3 base (radio or NTRIP, depending on your setup). Confirm the drone reports a fixed RTK solution before takeoff.

• 4. Fly the mapping mission

  Execute your planned LiDAR or photogrammetry flight. Log GNSS data on the drone if your workflow also uses PPK as a backup.

• 5. Capture a small set of RS3 checkpoints

  After the flight, walk the site with the RS3 rover and collect checkpoints on visible, durable features such as painted targets, corners, or manholes. Store these as Checkpoints in Emlid Flow and sync to Flow 360.

• 6. Process data and verify in the office

  Process the RTK-enabled drone data in your mapping software. Compare the drone model against RS3 checkpoints to validate accuracy and identify any consistent bias before issuing surfaces or quantities.

Result: The RS3 anchors both the drone and the rover to the same local coordinate frame, which reduces transformation headaches and builds confidence in your mapping outputs.

Workflow 3: RS3 as a PPK Base for LiDAR and High-Accuracy Photogrammetry

Construction sites do not always provide clean RTK radio conditions. This workflow mirrors what Emlid users are doing in dense canopy and remote environments, but applied to construction and infrastructure projects.

Goal: Use RS3 raw data in a PPK pipeline to correct the drone trajectory and achieve centimeter-level mapping even when real-time links are unreliable.

Steps:

• 1. Set up RS3 base logging

  Place RS3 on a control point or a stable location that you can later tie to control. In Emlid Flow, enable raw data logging (RINEX) for the duration of all flights.

• 2. Fly with onboard GNSS logging enabled

  Configure the drone to log raw GNSS data (or high-frequency position logs, depending on the platform). Run your LiDAR or photogrammetry missions as usual. The flight does not need a perfect RTK link.

• 3. Download base and drone logs

  After the flights, export RS3 RINEX logs from Emlid Flow or Flow 360. Download the drone GNSS log files.

• 4. Process PPK in Emlid Studio

  Use Emlid Studio to combine RS3 base logs with drone logs. Compute a corrected trajectory with RTK-grade accuracy based on the base station position.

• 5. Feed the corrected trajectory into your mapping software

  Import the corrected trajectory into your LiDAR or photogrammetry suite. Rebuild the point cloud or orthomosaic using the corrected positions.

• 6. Validate with RS3 checkpoints

  As in the previous workflows, use RS3 checkpoints collected on hard features to validate horizontal and vertical accuracy of the final deliverables. Document the error statistics for internal QA and for owner reporting.

Result: Even on cluttered or obstructed sites, you preserve survey-grade accuracy by resolving positions in post rather than depending only on a live RTK link.

Workflow 4: RS3 + GIS Apps for Utility, Surface, and Asset QA

This workflow lines up directly with common GIS integrations: Reach receivers feeding accurate positions into ArcGIS Field Maps, Survey123, and other GIS tools.

Goal: Stream RS3 positions into GIS apps so field crews can compare drone-derived data with real-world conditions and maintain a living model of utilities, surfaces, and assets.

Steps:

• 1. Pair RS3 with a tablet or phone

  Connect RS3 to your device via Bluetooth in Emlid Flow. Confirm you have RTK corrections (CORS, local base, or RS3 acting as base).

• 2. Configure position streaming

  In Emlid Flow, enable NMEA streaming over Bluetooth or TCP, depending on what your GIS app expects. Match coordinate systems between RS3, Flow, and your GIS project.

• 3. Select RS3 as the location source in the GIS app

  In ArcGIS Field Maps, Survey123, QField, or similar, set the RS3 as the external GPS source. Verify that the reported accuracy in the app is at the centimeter or sub-decimeter level, not at smartphone GPS accuracy.

• 4. Capture utility and surface features in context

  Walk the site and collect buried utility locations, valve boxes, manholes, poles, signs, structures, permanent assets, edges of pavement, grade breaks, and key elevations. Use RS3 tilt compensation where access is restricted.

• 5. Compare against drone deliverables and design

  In the office, overlay GIS features captured with RS3 on top of drone-derived rasters and point clouds. Use this to verify that utilities, structures, and surfaces are where the model says they are, and to support RFIs or design changes with clear spatial evidence.

• 6. Maintain a live, accurate record

  Keep the RS3-fed GIS layers as your single source of truth for as-builts and infrastructure over the life of the project. When you run new flights, you are aligning to an established, stable dataset instead of starting from scratch.

Result: GIS, drones, and GNSS are all synchronized. VDC, engineering, and field teams can look at the same map and trust that each point reflects reality within a known tolerance.

Scaling GNSS Access Without Losing Quality

Most large construction teams reach the same breaking point: there is more work that needs verification than the survey crew can touch in a day. Crews wait. Layout gets delayed. Decisions stack up behind unanswered questions. Meanwhile, superintendents and VDC managers have the digital tools to catch issues earlier. They just cannot access a rover without pulling it from survey.

This is the gap the RS3 fills. It gives multiple field roles controlled access to high-accuracy GNSS without undermining the precision the project depends on.

The problem is not accuracy. It is availability.

Traditional survey-grade GNSS is often locked inside a single team. That team is busy. Their schedule is packed. Their workflows are optimized for layout and critical control, not for every small verification task that appears between trades and phases. The bottleneck comes from how the work is organized, not from what the hardware can do.

A second or third rover changes the shape of the job.

When field engineers, foremen, or assistant supers have their own GNSS tool, they stop guessing. They stop relying on tape offsets or visual checks. They start collecting actual measurements before work progresses. This does three things immediately:

• Reduces the number of RFIs related to geometry

• Lowers rework risk by catching misalignment early

• Gives VDC the data it needs without waiting for survey availability

Consistency is what makes this viable.

Putting more rovers in more hands only works if all devices operate on the same coordinate framework, use the same control, and produce data that the office can trust. This is where the RS3 ecosystem matters.

A fleet of RS3 units stays coordinated because:

• Each rover connects to the same local base or CORS source

• Projects in Flow and Flow 360 enforce consistent coordinate systems

• Feature codes match the model rather than whatever the operator types in the field

• Tilt compensation reduces operator-to-operator variability in tight areas

This consistency keeps expanded GNSS access from eroding data quality.

More GNSS access improves the drone workflow too.

When multiple crews are collecting checkpoints, utility as-builts, or grade shots throughout the week, the drone team inherits a cleaner control environment. Every flight, whether weekly or on another regular cadence, aligns to richer ground truth. This reduces reconciliation time in the office and limits the number of reshoots.

The impact on operations is measurable.

On active projects, expanding GNSS access leads to:

• Faster QC cycles because questions get answered on site instead of waiting for survey

• Lower rework because teams verify before committing to irreversible work

• Fewer RFIs because measurements replace ambiguity

• Reduced bottlenecks since verification becomes a shared responsibility

• Higher model fidelity because more spatial data makes its way back into VDC workflows

These gains compound as projects scale. A mid-size GC with three RS3 kits experiences the benefits differently than an ENR Top 100 contractor running a dozen units, but the pattern is similar: better access produces better data, which supports better decisions.

At its core, greater GNSS access is about autonomy. Field teams can verify, document, and communicate geometry without waiting. Survey teams stay focused on high-risk layout and structural control where their expertise matters most. VDC receives cleaner, more frequent updates. The entire project benefits from tighter alignment between what is planned, what is built, and what the drone sees.

Why Contractors Choose RS3 Over Higher-Cost GNSS Platforms

Construction teams rarely switch GNSS tools because of a single feature. They switch when a solution meets their technical requirements without the financial or operational overhead that usually comes with enterprise-grade survey systems.

The RS3 sits in that middle ground. It is not a replacement for your most advanced survey instruments, and it is not competing with them. It fills the space where teams need reliable accuracy, fast deployment, and predictable workflows without tying up specialized survey personnel.

Cost structure matters.

Many contractors add GNSS capacity not because they want a cheaper rover, but because they want more rovers. A lower cost per unit makes it realistic to equip multiple field roles without sacrificing data quality or consistency.

The learning curve is shorter.

Field engineers and foremen can get productive quickly because Flow and Flow 360 handle much of the project structure for them. This reduces operator variability and lowers the training burden for VDC and survey leads.

Interoperability reduces friction.

The RS3 works cleanly with drones, GIS tools, CAD and BIM exports, and existing total station workflows. It enhances the toolchain rather than replacing it, which lowers resistance from crews and minimizes disruption to established processes.

The result is practical.

Contractors adopt RS3 when they need more verification capacity, faster QA cycles, and tighter alignment between field conditions and design intent. It delivers those gains without forcing a shift in the entire technology stack.

What This Means for Construction Teams Moving Forward

The pressure on schedules, budgets, and verification accuracy is not slowing down. Projects depend on fast field validation, consistent QA documentation, and tight alignment between the digital model and the physical site. The RS3 fits directly into that environment because it strengthens the link between design intent and daily execution without increasing operational overhead.

Construction teams that pair GNSS, drone mapping, and streamlined field software begin to see a pattern. Control is easier to maintain. Check shots can happen whenever the crew needs them. As-builts are captured before they become a problem instead of after an RFI chain starts. Field teams do more of their own verification, which frees survey specialists to focus on high-value tasks rather than constant interruptions.

This is the direction QA workflows are trending. Not toward replacing survey professionals or abandoning total stations, but toward giving more people the ability to contribute accurate, reliable data with confidence. The RS3 provides a practical way to do that, especially for teams that need to expand verification capacity without expanding headcount.

As contractors continue to adopt digital workflows and align field conditions with BIM and drone-derived surfaces, tools like the RS3 become part of the standard toolkit. It marks a shift toward QA workflows that are faster, more predictable, and more accessible to the people doing the work on site.

Learn more about Emlid RS3 here.