MO Land Surveyor common mistakes
MO Land Surveyor · Understand the traps and how to avoid them.
When retracing a boundary, the surveyor accepts the record bearing and distance without checking for a 'bust' in the original survey, and fails to recognize that the original monument controls over the record measurement.
Candidates memorize the principle that monuments control over measurements, but under exam pressure they mechanically apply record distances to compute a closure or area, forgetting that the physical monument is the best evidence of the original boundary location.
What to do instead
Before any calculation, identify all controlling monuments and compare record versus measured values; if a discrepancy exists, document it and hold the monument unless there is clear evidence of disturbance or fraud. Practice problems that require deciding between record and measured values, and always state the hierarchy of evidence in your answer.
On Missouri Minimum Standards questions, the candidate cites a generic national standard or a remembered number from another state instead of the specific Missouri statute or administrative rule.
Many surveying programs teach ALTA/NSPS standards or state-agnostic practices; candidates assume Missouri's standards mirror those, but Missouri has its own minimum standards for boundary surveys and plat requirements under the Missouri Revised Statutes and the State Board rules.
What to do instead
Create a one-page summary of Missouri-specific requirements (e.g., Missouri Revised Statutes Chapter 60 for surveys, and the Missouri Board for Architects, Professional Engineers, Professional Land Surveyors and Professional Landscape Architects rules). Memorize the specific citations and thresholds, and practice writing them from memory.
In coordinate geometry problems, the candidate confuses grid azimuth with geodetic azimuth and fails to apply the mapping angle (theta) or scale factor correctly, leading to misclosure or incorrect inverse computations.
Candidates learn State Plane Coordinate systems in theory but under time pressure they treat grid distances and ground distances as interchangeable, forgetting that scale factor and convergence must be applied when converting between ground and grid.
What to do instead
Work through a full example: given ground coordinates, compute grid coordinates using the combined factor, then compute grid azimuth from grid coordinates, and convert back to geodetic azimuth by adding or subtracting the mapping angle. Practice with actual Missouri coordinate zones (e.g., Missouri East and West) and verify with known test points.
When reducing field measurements, the candidate applies a correction for temperature or tension to a total station distance but forgets to apply the atmospheric correction (ppm) or incorrectly uses the wrong refractive index.
Candidates often memorize the formula for prism constant but overlook that total station distances require an atmospheric correction based on temperature and pressure, or they apply the correction with the wrong sign.
What to do instead
Develop a checklist for distance reduction: instrument and prism constants, atmospheric correction (using the formula or the instrument's built-in function), and scale factor. Practice with sample data where the correction changes the result by a measurable amount, and always record the environmental conditions.
In cadastral mapping questions, the candidate incorrectly assumes that a lot's area is exactly as shown on the plat, ignoring that areas may be approximate and that boundary lines may have been altered by subsequent conveyances or adverse possession.
Candidates treat the plat as a precise mathematical document, but in reality, plats are often based on field measurements with allowable tolerances, and lot areas may be rounded; also, exam questions may test the principle that area is the least reliable element of a description.
What to do instead
Review the hierarchy of evidence: natural monuments, artificial monuments, courses and distances, then area. Practice problems where area conflicts with monuments, and remember that area is subordinate. Also, study Missouri case law on boundary by acquiescence and adverse possession to understand how boundaries can change.
When interpreting a PLSS description, the candidate treats the section as a perfect square mile and fails to account for fractional lots, correction lines, and the effects of the Public Land Survey System's rules for meander lines and closing corners.
Textbook examples often use idealized sections, but real PLSS surveys have irregularities due to earth's curvature, surveying errors, and the need to place excess or deficiency in the north and west tiers. Candidates forget that the north and west boundaries of a township are the ones adjusted.
What to do instead
Study the PLSS manual rules: the north boundary of a township is a correction line, and the west boundary is a standard parallel; within a section, the north and west quarter-quarter corners are set by proportional measurement. Practice with a township diagram that has excess/deficiency and compute the aliquot parts correctly.
In construction surveying, the candidate stakes out a point using coordinates but fails to check for a bust in the control network or to verify the instrument setup with a backsight check, leading to systematic error.
Candidates focus on the math of stakeout but overlook field procedures; they may set up on a point without checking the backsight distance and angle, or they may use a control point that has been disturbed.
What to do instead
Always perform a backsight check and a closure check on control before stakeout. In exam questions, look for clues that the control may be inconsistent and describe the proper procedure: occupy a known point, backsight another known point, check the measured distance and angle, and if the error exceeds tolerance, re-establish control.
When preparing a topographic map, the candidate uses a contour interval that is too large for the terrain, or fails to correctly interpolate between spot elevations, resulting in contours that do not represent the ground truth.
Candidates may choose a standard contour interval without considering the purpose of the map or the slope; they also may not understand that contours are interpolated linearly between measured points, and errors in interpolation lead to misrepresentation.
What to do instead
Study guidelines for contour interval selection based on map scale and terrain relief. Practice interpolating contours from spot elevations and breaklines, and remember that breaklines (e.g., top of bank, toe of slope) must be honored. Review Missouri minimum standards for topographic mapping if applicable.
On ethics questions, the candidate selects the answer that is legally permissible but ethically questionable, such as accepting a boundary survey commission without disclosing a conflict of interest or without the competence to perform it.
Candidates often focus on the letter of the law and forget the professional code of ethics, which requires disclosure of conflicts, competence, and avoidance of misleading advertising. They may not recognize that the duty to the public outweighs client demands.
What to do instead
Review the Missouri Board's rules of professional conduct and the NSPS/ACSM Code of Ethics. Practice scenario questions where the correct answer is to decline the work or disclose a conflict, even if it costs the client. Emphasize the canons: protect public safety, be honest, and only practice within your competence.
In business practice questions, the candidate fails to distinguish between a lien and a boundary survey, or incorrectly assumes that a surveyor's lien attaches to the property without proper notice and recording under Missouri's mechanics' lien statutes.
Candidates may not be familiar with Missouri's specific lien laws for surveyors, which require timely filing and notice; they may also confuse a surveyor's lien with a mechanic's lien or assume it is automatic.
What to do instead
Study Missouri Revised Statutes Chapter 429 regarding mechanics' and materialmen's liens, and specifically the provisions for professional services. Understand the deadlines, notice requirements, and the difference between a lien on the property and a claim against the client. Practice with timelines and documentation requirements.