Causes of Errors and 7 Countermeasures in Surveying for Solar Power Plants

Table of Contents

• Why error control is important in surveying for solar power plants

• Cause 1: Ambiguous placement and management of control points

• Cause 2: Mixing up coordinate systems or drawing conditions

• Cause 3: Insufficient instrument setup and leveling

• Cause 4: Effects of satellite reception and communication environments

• Cause 5: Poor line-of-sight and visibility due to terrain and obstacles

• Cause 6: Insufficient alignment between site conditions and design conditions

• Cause 7: Mistakes in post-survey record organization and data processing

• Summary

Why error control is important in surveying for solar power plants

In surveying for solar power plants, small errors can lead to major rework in later stages. Surveying accuracy is important in ordinary building sites or paving works as well, but solar power plants typically cover a wide area and involve multiple simultaneous factors—terrain undulations and slopes, earthworks plans, drainage plans, racking layout, pile locations, maintenance access routes, and more—so errors tend to propagate across the entire site.

For example, even a slight offset in the location of a control point can affect pile center layout, verification of design heights, rack alignment, and routing of cable runs. Individual discrepancies may seem small on site, but when accumulated over long distances they can break overall consistency and often necessitate re-surveying or rework.

Solar power plant sites are not always flat. There are many environments where observation conditions are unstable: sloping ground, embankments, overgrown undeveloped areas, tree-lined sections, or sites with existing structures. Therefore, it is essential not only to measure but also to anticipate where errors are likely to arise and to plan countermeasures tailored to site conditions.

Surveying errors are not solely the responsibility of field personnel. Because surveying links to design, construction, quality control, and schedule management, the accuracy achieved at the surveying stage affects the reliability of the entire project. That is why, for solar power plant surveying, it is important not to rely only on the performance of instruments but to establish systems to suppress errors that include control point management, observation procedures, drawing checks, data processing, and information sharing.

Below, the typical causes of errors in solar power plant surveying are organized into seven categories, and practical, field-applicable countermeasures for each are explained. The content is focused on items that practitioners can use as daily checklists to stabilize surveying accuracy.

Cause 1: Ambiguous placement and management of control points

A common starting point for surveying errors in solar power plant work is inadequate placement and management of control points. Because surveying develops positions and heights from control points, if the initial reference is unstable, subsequent as-built verification and layout will all be unstable. On large sites, different crews may treat control references differently, causing unnoticed cumulative errors.

Control point problems are not limited to simple placement mistakes. Temporary points used for long periods may have shifted, surrounding ground may have been disturbed by heavy equipment or delivery vehicles, or points may become hard to confirm because they are buried by grass or soil. Work often proceeds on the assumption that control points remain unchanged, but site conditions change daily, so the state at installation is not guaranteed to remain.

An important countermeasure is careful selection of control point locations. Choose positions that are less affected by heavy equipment, drainage, or ground settlement. Record the control point name, coordinates, elevation, installation date, last confirmation date, and surrounding reference marks so anyone can refer to the same point. Using site photos and simple sketches as well as paper drawings reduces misidentification.

Developing a habit of checking and cross-referencing known points before starting work is also effective. Even if a control point was used the previous day, performing a confirmation observation at the start of the day helps detect anomalies early. If distances or directions between control points show unnatural differences, do not continue work; isolate where the control problem lies first.

Control points are not a one-time setup; they are the foundation supporting overall site quality. The wider and longer the project—like a solar power plant—the more important it is to clarify control point management rules and standardize recheck procedures as the first step in preventing errors.

Cause 2: Mixing up coordinate systems or drawing conditions

Even with high-performance surveying instruments, large position discrepancies can occur if understanding of coordinate systems or drawing conditions is unclear. Solar power plant work requires crossing multiple drawings—existing conditions, earthworks plans, racking layout, drainage plans—so if it is not clear which drawing assumes which coordinate conditions, field alignment will fail.

A common issue is that plane positions may look correct, but the underlying coordinate concepts differ, or drawing dimension references and site reference directions are misaligned. Be cautious when old and new drawings coexist due to design changes. Field teams may think they are using the latest version, but if another person uses older data for surveying, later consistency checks can fail.

A practical countermeasure is to consolidate the drawing and data conditions used for work onto a single confirmation sheet before starting. Agree on which drawing is the reference, which coordinate data to adopt, what the elevation datum is, and whether design changes have been incorporated. Because verbal sharing can leave residual misunderstandings, document drawing numbers and revision dates.

Also, for data taken into the field, do pre-calculations and provisional expansions and verify consistency at representative points. Choose several easy-to-check points—design corners, pathway intersections, relationships to existing structures—and compare drawing data with actual measurements beforehand to avoid confusion during work.

While people tend to focus on mechanical sources of surveying error, errors caused by misinterpreting drawing conditions can take longer to correct. In solar power plant surveying, organizing information before measuring is the key to ensuring accuracy.

Cause 3: Insufficient instrument setup and leveling

A surprisingly common oversight in the field is neglecting fundamental tasks related to instrument setup and leveling. No matter how high-performance the equipment, basic mistakes—insufficient tripod setup, inadequate leveling, incorrect input of instrument height or prism height—can easily corrupt observations. This is especially likely when crews are rushed.

Solar power plant sites often present conditions where stable instrument setup is difficult: soft ground, slopes, or temporary crushed-stone access ways. Even when an instrument appears level, the tripod can sink slightly or the legs can slip during observation. Such small movements can cause non-negligible errors when laying out points over long distances.

Countermeasures include checking the condition of the setup surface and, when necessary, moving the tripod, tamping the ground, or selecting a more stable support. Do not rely on the initial leveling alone; recheck leveling during observation and upon resuming work to stabilize accuracy. Routine basic checks are especially helpful when temperature or sun exposure reduces concentration.

Also, instrument height and target/prism height inputs are prone to mistake even by experienced staff. Values change with different equipment and accessories used at each site, so measure them each time and record them. Having another person verify inputs before and after entry can prevent many simple mistakes.

Errors related to equipment can be hard to diagnose from data alone after observations. Therefore, carefully record instrument condition, setup status, input values, and observation times. In solar power plant surveying, strictly following basic procedures is the most reliable way to prevent errors.

Cause 4: Effects of satellite reception and communication environments

When using satellites for positioning, changes in reception and communication environments directly affect errors. Candidate or construction sites for solar power plants include open areas as well as locations near trees, valleys, slopes, and stored temporary materials, so observations cannot always be made under identical conditions. Reception quality varies by location, so even with the same equipment accuracy may not be consistent.

Be especially aware of cases where the sky appears open but parts are actually obstructed. Near high embankments, forest edges, poles, or fences, reception directions can be biased. In operations that use correction data, unstable communication can delay achieving a fixed solution or make observed values unstable. Field teams often proceed while trusting numeric displays, but poor reception conditions are a frequent latent error source.

Countermeasures include identifying easily receivable and poorly receivable locations on the site before work. For large sites, rather than a single uniform observation plan, consider changing methods by area. In areas with unstable reception, allow longer observation times, perform confirmatory observations using alternative methods, or use auxiliary points with clear sky views—operate with margin.

Also, do not rely solely on displayed values; cross-check with known points and perform multiple observations. Conditions may be good in the morning and change by afternoon, and weather or surrounding work can affect reception. Being aware of time-of-day differences helps reduce unexplained discrepancies.

The effects of satellite reception and communication can never be reduced to zero. However, by adapting observation methods to site conditions and backing up values with confirmations, error growth can be sufficiently limited. Reading the observation environment before bringing equipment to a solar power plant site makes a big difference.

Cause 5: Poor line-of-sight and visibility due to terrain and obstacles

Underestimating the influence of terrain and obstacles on line-of-sight and visibility can easily cause errors on solar power plant sites. Areas that look simple on the plan may have undulations, steps, embankments, debris, weeds, trees, or temporary materials on the ground, making it difficult to secure adequate sight lines. Especially on sites where terrain changes before and after earthworks, the ease of observation can vary day by day even along the same route.

If you force observations where visibility is poor, target placement can become unstable, aim may be lax, and the interpretation of the survey point itself can be skewed. At ambiguous boundaries like slope crests or toes, the result changes depending on which point is chosen as representative. This is not a mechanical problem but a matter of reading site morphology and setting survey points.

As a countermeasure, identify locations with poor visibility during site reconnaissance and, if necessary, review observation routes and control point placement. Rather than forcing a straight line, dividing the work using auxiliary points with clear sight lines tends to stabilize both accuracy and efficiency. Simple pre-clearing of weeds or minor obstacles can significantly improve observation conditions.

Also, unify criteria on which position to count as a survey point. If different personnel choose slope top, inflection points, or structure edges differently, measurements at the same location will not be consistent. Sharing the meaning of survey points before work reduces terrain-derived errors.

Because solar power plant surveys cover wide areas, one location with poor visibility can disrupt the overall workflow. Therefore, plan observations based on site terrain and obstacles and prioritize conditions in which correct measurements can be taken rather than those that are merely easy to measure.

Cause 6: Insufficient alignment between site conditions and design conditions

What appears to be a surveying error is often caused by differences in understanding between site conditions and design conditions. In solar power plants, designs may be valid on paper, but actual terrain, existing structures, drainage direction, construction yards, and delivery routes can make direct implementation of design positions impossible. Forcing design values onto site conditions without adjustment leads to work proceeding without understanding the source of discrepancies.

For example, if drawings are based on pre-earthwork ground conditions but site-ground conditions changed during construction, the same elevation or position instruction can have a different meaning in the field. Prioritizing rack layout may reduce pathway widths, while prioritizing drainage slope may require adjusting pile positions. Treating these issues simply as measurement errors hides the fundamental problem.

As a countermeasure, surveying personnel should understand not only the numeric values on drawings but also what those numbers are intended to achieve. If you grasp the design intent—earthwork heights, drainage directions, required clearances from structures, maintenance flow—then you will notice inconsistencies earlier in the field. Before re-measuring based on onsite judgement, organize and share the differences between design intent and actual conditions.

Establishing checkpoints where design, construction, and surveying personnel review alignment is also effective. Confirming site and drawing consistency at process milestones—before start, after earthworks, before pile layout, and before as-built verification—helps avoid major rework. Proceeding based solely on drawing conditions when the site has changed is the most dangerous practice.

In solar power plant surveying, do not judge discrepancies solely by numbers. When a deviation appears, distinguish whether it is a measurement error, a drawing-condition issue, or a site-change. Sites that can make this distinction tend to reduce unnecessary rework and better balance accuracy and schedule.

Cause 7: Mistakes in post-survey record organization and data processing

Even if field observations are correct, errors and mistakes can creep in during record organization and data processing. Solar power plants have many survey points and wide areas, so confusion in file naming, date management, point naming, drawing updates, or deliverable organization makes later root-cause investigation difficult. When multiple people share tasks, inconsistent recording methods easily break the integrity of results.

Common problems include accidentally overwriting files with the same name, using old data as the latest, mixing data from different observation dates, or having teams use different point numbering schemes. These mistakes are hard to detect on site and often surface after reflecting data in design or as-built drawings, making correction costly.

A countermeasure is to adopt simple, unified recording rules. Define naming conventions that clearly show point name, observation date, crew, area name, and data type so organization accuracy improves. If you keep paper field books or notes, make them interpretable by anyone. Excessive abbreviations or unique notations cause misreading downstream.

Also, do not rely solely on office processing after returning from the field; implement same-day quick-checks. Reconfirm representative points, provisionally reflect data onto drawings, and check for missing observations within the day so that necessary supplementary surveys can be judged for the next day. The longer it takes to notice an anomaly, the harder it is to identify the cause.

The quality of data processing is as important as the quality of field surveying. For solar power plant surveying, duties also include recording correctly, sharing correctly, and handing off to the next process correctly. Systematizing this workflow completes the set of countermeasures for errors.

Summary

Errors in surveying for solar power plants are not caused solely by inadequate instrument accuracy. They stem from many aspects of site operations: lax control point management, mixing up coordinate conditions, poor instrument setup, changing reception environments, terrain and obstacle effects, design recognition gaps, and mistakes in record organization. Therefore, error control should not be left to one instrument or one person; it is important to organize the flow from pre-work checks through observation, inspection, and record-keeping.

Because solar power plants have wide sites, long schedules, and many stakeholders in design and construction, a mindset of not dismissing small deviations is required. Although it is difficult to eliminate errors completely, knowing where they tend to occur, detecting them early, and using multiple confirmation methods significantly reduces the risk of rework and reconstruction. What field sites need is not something special but a system that continues to perform the basics without omission.

If you want to make position and as-built verifications on large sites more efficient, incorporating methods that allow quick onsite confirmation of positioning results is also effective. For example, LRTK (iPhone-mounted GNSS high-precision positioning device) and similar tools that make coordinate checking and layout more accessible on site help institutionalize routine control point checks and daily accuracy management. Reducing surveying errors for solar power plants requires not only knowing the causes but also having verification methods that can be continued easily on site.