5 Points to Check Before Proceeding with Cadastral Surveying Using an Electronic Distance Meter (EDM)

Cadastral surveying is an important survey conducted to organize land parcel boundaries, areas, and positional relationships. Using a total station in the field allows angles and distances to be measured efficiently and the positions of boundary points and control points to be recorded numerically. However, reliable results cannot be achieved by instrument performance alone. If work begins without sufficient preliminary checks, errors such as mixing up coordinate systems, misidentifying known points, overlooking boundary points, unstable observation conditions, and repeat work due to insufficient records are likely to occur.

In cadastral surveying in particular, you should not base judgments solely on values measured on site; it is necessary to organize them by combining registration-related documents, existing drawings, control point information, the results of on-site attendances by relevant parties, and the physical conditions of the site. A total station is an effective tool for recording positional relationships in a reproducible manner, but if preparation before use is inadequate, it becomes difficult to later justify the reliability of the measurement results.

In this article, we explain five practical points to check before conducting cadastral surveys with a total station. From a field practitioner's perspective, we outline what on-site personnel should review before starting work and what preparations can minimize rework.

Table of Contents

• Organize the objectives and scope of cadastral surveying in advance

• Confirm the consistency of the control points and coordinate system to be used

• Check the condition of the total station and its accessories

• Decide the procedures for verifying boundary points and on-site conditions in advance

• Standardize the rules for observation records and the organization of results in advance

• Summary

First, clarify the purpose and scope of cadastral surveying

Before starting cadastral surveying with a total station, the first thing to confirm is the purpose: what you intend to clarify with this survey. Even within cadastral surveying, the scope of what to inspect on site and the details to record vary according to the purpose—for example, arranging the positions of boundary points, comparing with existing drawings, understanding current conditions for area calculation, or preparing baseline data for re-surveying.

If you enter the site without a clear purpose, you tend to measure only the points that can be measured with a total station in sequence, which later leads to problems such as "this point was also needed," "the relationship with adjacent land is unclear," and "the point names on the plans don't correspond to the stakes on site." In cadastral surveys, not only the measurement points themselves but also surrounding roads, waterways, structures, existing stakes, fences, retaining walls, slopes, and the usage status of farmland and residential land can serve as factors for judgment. Therefore, before surveying, it's important to organize the scope of verification to include not only the target land but also its relationship with adjacent parcels.

When determining the working area, do not look only at the perimeter of the subject parcel; consider how far you need to establish reference points and auxiliary points. A total station can measure efficiently where a clear line of sight is available, but if the line of sight is blocked by buildings, trees, fences, changes in elevation, vehicles, material storage areas, etc., it may be impossible to measure all required points from a single instrument setup. In cadastral surveying, obstacles near the boundaries are not uncommon, so rather than scrambling to find instrument stations after arriving on site, use preliminary documents and reconnaissance information to roughly anticipate from where you will observe which points.

Also, in cadastral surveying it is important to ensure consistency with past records. When there are materials such as official cadastral maps, land area survey maps, past survey results, current-condition maps, on-site meeting records, and documents related to boundary confirmation, prepare in advance which points to be checked on site correspond to which documents. Because the materials differ in their creation dates, accuracy, and purposes, rather than treating them all with equal weight, it is necessary to confirm before going to the field which documents will be used as reference information and which will be the primary subjects of cross-checking.

What you should pay particular attention to is that lines on drawings do not necessarily coincide with conditions on site. In older documents, the influence of scale and drafting methods may cause the positional relationships on the drawing not to fully match the current conditions. The numerical values obtained with a total station can help objectively record the on-site conditions, but which documents those values are compared with and the extent to which they are treated as a basis for judgment must be decided carefully according to the purpose of the survey.

Before starting work, organizing the extent of the site, its relationship with adjacent properties, boundary points to be checked, planned measurement points, necessary auxiliary points, locations requiring an on-site witness, and entry conditions helps stabilize decision-making in the field. If personnel have different understandings, even when using the same total station, differences will appear in which points are measured, how point names are assigned, and how records are kept. If the person who compiles the deliverables in later stages is someone different, sharing the work scope in advance is all the more essential.

Cadastral surveying can appear simple if you consider only the measurement tasks in isolation. However, in practice, document review, on-site verification, stakeholder confirmation, observation, calculation, drafting, and result compilation are all linked in a continuous sequence. To use a total station effectively, the first step is to clarify before you begin measuring, "how far will you measure," "what will you compare it against," and "what results will it feed into."

Confirm consistency of the reference points and coordinate systems to be used

When using a total station in cadastral surveying, verifying the control points and the coordinate system is extremely important. No matter how carefully you observe, if you select the wrong control point or mishandle the coordinate system, the entire set of measurements will be displaced. Even if each observation in the field appears correct, this can lead during the results compilation stage to a situation where the data do not match existing drawings or neighboring survey results.

First, what needs to be confirmed is what kind of control point will be used this time. There are various types of points that can serve as references: public control points, known points established in past surveys, arbitrary points within the site, temporary auxiliary points, and so on. Because their reliability and intended purposes differ, you should avoid using them unconditionally just because they exist on site. Check the point name, coordinate values, installation location, condition of the marker, past usage history, and the presence of any anomalies or deformations in the surrounding area, and determine whether the point is suitable for this cadastral survey.

When checking control points, the physical condition of the points themselves is also important. Observe whether markers such as pins or stakes have moved, whether their positions have been altered by pavement repairs or land development work, and whether they have been affected by surrounding structures. Even if they appear to remain, using points that may have settled, tilted, been damaged, or been relocated as control points can introduce errors into the measurement results. If possible, cross-check multiple known points and verify that the distances and directions between them do not significantly contradict the records before beginning the main survey.

Next, check the consistency of coordinate systems. In cadastral surveying, different concepts of coordinates can coexist among existing results, administrative records, design documents, and as‑built survey results. If you proceed without confirming whether the results are based on the plane rectangular coordinate system, a site‑specific local coordinate system, or past arbitrary coordinates, later coordinate transformations and matching tasks can cause confusion. When entering coordinates into a total station for observation, always verify which coordinate system the entered coordinate values are based on.

One thing to particularly avoid in cadastral surveying is handling different coordinate values under the same point name. Updates to past results, changes from provisional to official coordinates, expansion of the survey area, or performing coordinate transformations can lead to multiple coordinate values appearing in the documentation. Before bringing data to the field, it is necessary to consolidate the coordinate dataset to be used this time and manage it so it is not confused with old or reference materials. Organize point names, coordinate values, whether elevations are present, usability, and remarks, and confirm that the contents of the field-use data and the results-compilation data are consistent to be safe.

When setting up a total station, you should carefully choose the combination of instrument station and backsight. The instrument station should be located where it can be installed stably, and the backsight should be easy to sight and reliable as a reference direction. In cadastral surveys, because observations may be carried out in narrow passages near boundary points or on private property, it is necessary to take measures to avoid locations where the tripod feet would be unstable or where passersby and vehicles are likely to cause interference. If installation conditions are poor, rather than forcing observations from the primary station, it may be necessary to establish auxiliary points to stabilize the observation network.

Also, attention is needed to how observation distances and angles are taken from reference points to boundary points. Extremely short distances, extremely acute angles, directions with poor line of sight, and directions prone to heat shimmer or turbulence can cause observed values to become unstable. Rather than trusting the measurements of an electronic total station outright, check the observation conditions and, if necessary, plan for re-measurements, confirmations from other directions, and cross-checks from multiple points to improve the explainability of the results.

Checking the coordinate system and reference points is not preparation solely for shortening on-site work time. It is the foundation that determines whether the results of a cadastral survey are consistent with surrounding land information and past records. Before using a total station, confirming the reliability of the reference points, the type of coordinate system, the consistency of input data, and the combination of instrument and backsight points can reduce uncertainties when reviewing the survey results later.

Inspect the condition of the total station and its accessories

In cadastral surveying, work is carried out using a combination of multiple pieces of equipment, not only the total station itself but also tripods, prisms, mirrors, poles, leveling bases, batteries, recording media, field books, on-site terminals, and so on. Even a defect in any one of these can cause variability in observations or interruptions to work. In particular, because cadastral surveying is sometimes performed in parallel with on-site attendance and coordination with stakeholders, if equipment deficiencies halt work on site, re-adjustments can be time-consuming.

First, check the basic condition of the total station itself. Verify in advance whether the power turns on normally, whether there are any abnormalities in the display or operation, whether readings of horizontal and vertical angles are stable, and whether distance measurement can be performed as usual. Pay particular attention to equipment that has not been used for a long time or that was exposed to rain, mud, dust, or strong vibration at the previous site. If you perform operational checks for the first time only after arriving on site, it will be difficult to prepare alternatives if a malfunction is found.

Do not overlook the components related to leveling. Check whether the tripod legs can be securely fixed, whether the spikes are excessively worn, whether the leg clamps are loose, and whether the tribrach’s fastening and the condition of the spirit level show any abnormalities. In cadastral surveys, instruments may be set up in tight spaces near boundaries, on slopes, at the edge between pavement and soil, or on grass. If the tripod sinks slightly or shifts during work, it can affect the observations. It is important to verify not only the accuracy of the instrument itself but also the stability of the equipment supporting its setup.

The condition of prisms, mirrors, and poles is also important. Check whether the prism faces are dirty, damaged, or fogged; whether the pole’s scale markings are easy to read; and whether the telescoping sections can be securely locked. The mirror height and prism constant settings directly affect measurement results. If the prism or reflective target used on site changes, the settings on the electronic distance measuring instrument must also be checked accordingly. If the previous site settings remain, they may not match the current measurement conditions.

Maintaining the verticality of the pole is also an element that should not be overlooked in cadastral surveying. Boundary points may be indicated by small nails, stakes, stone markers, metal markers, notches, corners of structures, and the prism must be correctly aligned to them. If measurements are taken with the pole tilted, the recorded position of the point may be displaced. Checking in advance that the pole’s bubble level is functioning, that it is positioned where the holder can easily check it, and that it is less susceptible to wind or footing effects will make it easier to reduce variability during observations.

Preparation of batteries and recording-related equipment is also indispensable. In cadastral surveying, on-site checks can take longer than planned. The progress of joint inspections, searching for boundary markers, removing vegetation, ensuring line of sight, and confirming matters with adjacent properties can all extend observation time. By checking spare batteries, charge levels, recording capacity, data storage locations, and backup recording methods in advance, you can reduce the risk of having to stop work midway. In particular, it is important to standardize the procedures for saving observational data and making backups among personnel.

For total station settings, check the distance-measurement mode, how atmospheric correction is handled, the prism constant, mirror height, instrument height, point-name input, coordinate input, unit settings, and so on. The same settings are not necessarily correct for every site. Depending on the equipment used, the observation method, and how the results are to be produced, it is important to confirm the necessary settings. Speak the settings aloud before starting work on site, and, if possible, keep a record of them so it is easier to make judgments when reviewing the measurements later.

Additionally, equipment checks should be carried out not only to determine whether the gear is usable, but also from the perspective of whether it is suitable for the current cadastral survey. On sites that require long-distance sighting, sites with many trees or buildings, sites where boundary points are densely concentrated, or sites where observations must be made across roads, the required equipment and safety measures will differ. Rather than treating preparation of the total station as a simple checklist of items, confirming it against site conditions increases the stability of the surveying work.

Establish procedures for confirming boundary points and on-site conditions

In cadastral surveying, confirming boundary points is central to the work. However, boundary points are not always neatly preserved in obvious locations; they may be overgrown with vegetation, buried under pavement or soil and sediment, represented by old stakes that have tilted, or appear to be integrated with adjacent structures.

Before measuring with a total station, it is important to decide the order in which you will search for, verify, and record boundary points.

First, you need to match the points shown in the documents with those on site. While checking the point names, distances, bearings, and adjacency relationships indicated on the drawings, verify them against on-site markers such as stakes, pins, stone markers, corners of fences, and ends of retaining walls. Do not immediately treat a found marker as a control point; instead, confirm its relationship with surrounding points and its consistency with the documentation. In cadastral surveying, it is important to assess overall consistency from the positional relationships of multiple points rather than judging based on a single point alone.

When verifying boundary points, whether relevant parties were present and the verification status should also be recorded. Depending on whether a point was confirmed by relevant parties, found on site as a marker but not verified, or exists in records but could not be confirmed in the field, it will be handled differently in later processes. Even if coordinates are obtained with a total station, if it is not clear on what basis the point was measured, it becomes difficult to organize the results. It is important to keep the point's condition and the verification history together.

When checking on-site conditions, we look at not only the boundary points themselves but also the surrounding features. Road boundaries, waterways, gutters/side ditches, walls, fences, retaining walls, buildings, slopes, steps/level differences, trees, utility poles, and drainage facilities can serve as auxiliary information to explain the positional relationships of the boundary. Rather than measuring only the necessary points with a total station, we include nearby features in the survey as needed so that later, when viewing drawings or records, it is easier to understand the on-site conditions.

However, increasing the number of measurement points too much makes point-name management and result organization complicated. Therefore, it is important to decide in advance the priority of the points to be measured. Distinguishing boundary points, control points, auxiliary points, feature points for verification, and points for explaining existing conditions, and unifying the method of assigning point names will make post-fieldwork organization smoother. Because point names that look similar are easy to mistake on total station data, establish the input rules to be used on site in advance as well.

Ensuring line of sight should also be considered part of the boundary point confirmation procedure. Even if a boundary point has been located, it cannot be measured unless there is line of sight from the instrument point to the prism. If vegetation, vehicles, temporary structures, walls, or building corners block the view, it is necessary to decide to change the observation position, set up auxiliary points, or alter the measurement order. When the person confirming the boundary points is different from the person operating the instrument, sharing which points to measure first and which to defer will help prevent work from being interrupted.

Also, in cadastral surveying, safety checks before entering the site are indispensable. Precautions vary depending on site conditions such as private land, farmland, forests, roadsides, waterways, and construction zones. It is necessary to work only within the scope agreed with the relevant parties, to respect access boundaries, not to obstruct passage or ongoing work, and to ensure that surveying equipment does not come into contact with third parties. The placement of the total station and the positions for holding prisms should also be determined after ensuring safety.

Verification of boundary points and on-site conditions is a crucial process that underpins the reliability of cadastral surveying. Coordinates measured with a total station alone do not convey the meaning or the basis of a point. By clearly specifying which points were verified, based on which reference materials, under what on-site conditions, and how they were recorded, the explanatory power of the results is enhanced.

Standardize rules for observation records and organizing results in advance

When conducting cadastral surveys with an electronic total station, as important as measuring correctly in the field is standardizing the rules for observation records and the organization of results. Even if the measured values themselves are correct, if point names, measurement conditions, confirmation status, photos, notes, and data storage locations are inconsistent, compiling the results later will take time. In some cases, what was measured on site may become unclear and require rechecking.

The first thing to decide is the rule for point names. In cadastral surveying you deal with points of different types, such as boundary points, control points, auxiliary points, as‑built points, and verification points. If these are managed only by sequential numbers without distinction, you will need to recheck the meaning of each point when producing drawings later. It is easier to organize if point names follow a systematic pattern that indicates the point type, measurement order, and applicable scope. However, overly complex point names can lead to data-entry errors in the field, so it is important to adopt concise rules that staff can operate without difficulty.

Next, standardize the method for recording observation conditions. Instrument point, backsight point, instrument height, mirror height, prism constant, distance-measuring mode, observation time, weather, visibility conditions, whether remeasurement was performed, and so on are important information for later verification of measurement results. Writing down every detail makes fieldwork burdensome, but if the necessary information is not recorded, it becomes difficult to explain the basis for the figures. Deciding in advance which items must always be recorded and which should be supplemented as needed according to the situation stabilizes the quality of the records.

Linking photographic records is also important. Photographs of the condition of boundary points, nearby features, instrument setup, obstacles that obstruct the line of sight, and the surroundings of points that could not be confirmed make later explanations easier. However, simply taking photographs is not enough. You need to organize which photograph corresponds to which point, the direction in which each photograph was taken, and whether the point names match the photograph numbers. Managing the EDM observation data, field book, photographs, and site notes so that they are linked together will improve the efficiency of organizing the results.

Confirm the data storage rules before starting work. Decide in advance what format to use for saving the observation data collected in the field, what names to use for the files, whether to separate files by workday or by survey area, and when to take backups; doing so makes it easier to prevent data overwriting and mix-ups. Especially when conducting cadastral surveying over multiple days or when multiple teams are working simultaneously, standardizing file names and storage locations is extremely important.

How to verify observation results is another item you should decide in advance. Whether you perform a quick on-site check of the points measured there or consolidate and verify them later at the office will change how you respond in the field. If possible, confirm on site the distances between known points, backsight checks, closure status, and relationships with adjacent points, and if anything seems significantly off, have a system in place to re-measure immediately. In cadastral surveying, because adjustments may be required to re-enter the site at a later date, it is important to detect mistakes that can be noticed on site as early as possible.

When compiling deliverables, we create items tailored to the purpose, such as an as‑is survey map, a list of boundary points, a list of coordinates, area calculation documents, and verification records. Observational data from a total station do not become deliverables as‑is; they are organized after assigning meaning to the points and cross‑checking them against documents. Therefore, if you keep in mind at the field stage which deliverable the data will be used for, you can reduce unnecessary measurements and omissions in recording.

Also, for items that will require judgment during the results compilation stage, it is important to leave detailed field notes. For example, reasons why a boundary marker could not be found, what was confirmed during the on-site inspection, relationships with surrounding features, points where measurements were deferred, and reasons for establishing auxiliary points cannot be understood from numerical data alone. By combining the coordinates obtained with a total station and the on-site judgment records, the deliverables become easier to handle in practice.

Standardizing the rules for observation records and result organization in advance is not merely about streamlining administrative work. It is the foundation for maintaining the reliability of survey results, making them easier to explain to stakeholders, and facilitating later verification and corrections. On sites that use total stations, where numerical data tend to be more abundant, it is essential to establish mechanisms for recording and organizing data before measurements.

Summary

Before proceeding with cadastral surveying using a total station, it is important not to bring the instrument to the site and start measuring immediately, but to check the purpose, scope, control points, coordinate system, equipment condition, boundary point verification, and recording method one by one. Cadastral surveying is not a task that is completed simply by measuring points on site; it is a process of linking documents, existing conditions, stakeholder confirmations, measured values, and the organization of results to make judgments. Therefore, the quality of the preparatory work directly affects how clear and reliable the results will be.

Particularly, ensuring consistency between control points and the coordinate system is the foundation that underpins overall positional accuracy. If work is started without verifying the condition of known points and the origin of their coordinates, it can later cause discrepancies with surrounding survey results. Likewise, neglecting inspections of equipment such as the total station, prisms, poles, and tripods can lead to measurement variability and work interruptions. Because cadastral surveying may require adjustments such as re-attendance or re-entry to the site, it is important to minimize problems that can be avoided on site in advance.

In confirming boundary points, record not only the presence or absence of markers but also the correspondence with documents, the relationship to surrounding features, the status of verification, and the results of any on-site joint inspections. Coordinates obtained with a total station are useful, but if it is not clear what the point represents or on what basis it was measured, they become difficult to treat as a reliable outcome. By linking observation data, photographs, field notebooks, and site notes, you create results that are easy to understand when reviewed later.

In cadastral surveying practice, site conditions vary from place to place. Some sites are flat residential lots with good lines of sight, while others are forests with many trees and level changes, land adjacent to roads or waterways, or areas where old boundary markers are mixed in. What is common to every site is that, to make the most of a total station's performance, pre-measurement checks and unified operational rules are indispensable. If you organize the points to check before starting work, on-site decision-making will be faster and rework can be reduced.

Going forward, in addition to measurements using total stations, it will also be important to have a system that consistently organizes on-site position information, photos, and notes. Rather than relying on specific products or methods, it is essential to establish recording methods and data-management workflows that fit site conditions, the deliverables required by clients, and internal operating rules. By linking everything from pre-measurement checks to the compilation of results, it becomes easier to stabilize the work quality of cadastral surveying.