Data Collection

Overview#

Data collection is the core purpose of fieldwork. Every measurement, observation, and notation made in the field becomes the raw material from which maps, plats, legal descriptions, and design files are produced. Poor data collection -- missing notes, ambiguous codes, unnamed points, lost files -- creates problems that are expensive or impossible to fix from the office.

The transition from paper field books to electronic data collectors has transformed how surveyors record data, but it has not eliminated the need for careful, systematic documentation. A data collector stores coordinates and codes; it does not record the context, judgment calls, or visual observations that a field book captures. The best field crews combine electronic precision with thorough written and photographic documentation.

"Field notes are the only evidence of work done in the field. They must be complete, legible, and organized so that anyone -- including a surveyor who was not on the crew -- can reconstruct what was observed and measured." -- Davis, Foote, Anderson & Mikhail, Surveying: Theory and Practice (6th Ed.), Ch. 3, p. 48

Field Notes#

What to Record

Regardless of whether you use a paper field book or electronic records, the following information must be documented for every survey:

Project Header (every day):

• Date and weather conditions (temperature, wind, visibility)
• Project name, number, and client
• Crew members and their roles
• Equipment used (instrument serial numbers, firmware versions)
• Datum, coordinate system, units, and geoid model
• Control points occupied (IDs, source of coordinates)

At Each Station Setup:

• Station point ID and coordinates
• Instrument height (HI) and measurement method
• Backsight point ID
• Backsight check (measured distance vs. known distance, measured angle vs. known angle)
• Time of setup

For Each Measurement:

• Point number and feature code
• Description (what the point represents)
• Any special circumstances (offset shot, estimated position, obscured point)

At the End of the Day:

• Summary of work completed
• Points of concern or follow-up items
• Closure checks performed and results
• Data files saved and backed up

Field Book Standards

If paper field notes are maintained (and they should be, even as a supplement to electronic records):

• Use only bound field books with numbered pages. Loose sheets get lost.
• Write in pencil (for durability) or waterproof ink.
• Never erase. Draw a single line through errors and write the correction alongside.
• Record on the right-hand page; sketch on the left-hand page.
• Sign and date each day's work.
• Field books are legal documents and may be subpoenaed. Treat them accordingly.

Sketching Conventions#

Why Sketches Matter

A field sketch provides spatial context that point numbers and codes alone cannot convey. It shows relationships between features, identifies what was measured and what was interpolated, and serves as a critical reference when processing data in the office.

Standard Practices

• Orient the sketch with north toward the top of the page. Include a north arrow.
• Label the sketch with the project name, date, and sheet number.
• Show the approximate positions of all survey points, labeled with point numbers.
• Indicate the nature of features: property corners (square symbols), fence lines, building corners, edges of pavement, utility structures, trees (with diameter and species if relevant).
• Show dimensions that were measured (solid lines) versus those that are approximate (dashed lines).
• Note ties to reference objects (fences, buildings, utility poles) with measured distances.
• Include street names, address numbers, and landmark names.
• Mark control points and benchmarks with distinct symbols.

Common Sketch Symbols

Electronic Data Collection#

Data Collector Workflow

Modern electronic data collection follows a structured workflow:

1. Create or open a project (job) on the data collector.
2. Import control coordinates -- Upload known points from the office before going to the field.
3. Configure the coordinate system -- Datum, projection, units, geoid model.
4. Set up the instrument -- Enter station, HI, backsight.
5. Collect measurements -- Each shot is stored with point number, code, and raw observations (angles, distance) as well as computed coordinates.
6. Apply feature codes -- Use a consistent code library to classify each point.
7. Perform check shots -- Re-measure known points to verify accuracy.
8. Save and export -- Transfer data to office software at end of day.

Advantages Over Paper

• Eliminates transcription errors (no manual entry of numbers).
• Coordinates computed in real time -- errors can be detected immediately.
• Feature codes drive automated drafting in CAD/GIS.
• Timestamps and metadata automatically recorded.
• Data can be backed up electronically.

Limitations

• Battery failure can halt data collection entirely.
• Dropped or damaged data collectors can lose a day's work if not backed up.
• Over-reliance on codes and coordinates can lead to incomplete contextual documentation.
• Software glitches can corrupt files. Always close and save projects properly.

Electronic data collection is not a substitute for field notes and sketches. It is a complement. The data collector records the numbers; the field notes and sketches record the story.

Feature Codes and Coding Systems#

Purpose

Feature codes are shorthand identifiers assigned to each survey point that describe what the point represents. A well-designed coding system allows office staff to generate preliminary maps automatically by connecting coded points into lines, curves, and polygons.

Code Structure

Most coding systems use a combination of a feature code (what the point is) and control codes (how to connect it to adjacent points):

Common Feature Code Library

A standardized code library should be established for each office or project. Here is a representative example:

Best Practices for Coding

• Use codes consistently. EP should always mean edge of pavement, never "east property."
• Keep codes short (2--4 characters) for fast entry.
• Include a printed code list in every field book and on the data collector.
• Train all crew members on the code library before starting a project.
• Use attribute fields for additional information (diameter, species, material, invert elevation) rather than creating dozens of specialized codes.

Point Numbering Systems#

Importance

A logical point numbering system prevents confusion, reduces errors, and makes data processing more efficient. Random numbering leads to misidentified points and wasted time.

Common Approaches

Recommendations

• Reserve low numbers (1--99 or 1--999) for control points and benchmarks.
• Assign topographic points a separate range from boundary/property points.
• Never reuse point numbers within a project. If a point is deleted, skip that number.
• Document the numbering convention in the project notes.

Photo Documentation#

Why Photograph

Photographs supplement field notes and sketches with unambiguous visual records. They are especially valuable for:

• Documenting the condition and markings of found monuments.
• Recording evidence of occupation, fencing, improvements, and encroachments.
• Showing site conditions before and during construction.
• Providing context for utility locations and infrastructure.
• Supporting boundary opinions in case of disputes.

Photo Standards

• Include a reference object for scale (survey rod, tape, hand for close-ups).
• Use a marker board or photo ID card showing project name, date, point number, and direction of view.
• Take overlapping photos of continuous features (fence lines, walls, improvements).
• Photograph both close-up detail and wide-angle context for each significant feature.
• For monuments: photograph the monument itself, then photograph from above showing surrounding context, then photograph from distance showing the monument's location relative to nearby features.
• Geo-tag photos when possible (most phones and cameras support this).

Organization

• Create a folder structure by date and/or area within the project.
• Name files consistently: PROJ-DATE-PTNUM-DESC.jpg (e.g., SV2024-0215-MON42-FOUND_IP.jpg).
• Transfer photos to the project folder on the same day they are taken.
• Include photo logs in the field notes with point numbers referencing specific images.

Control Point Documentation#

What to Document

For every control point (horizontal or vertical) used or established during a survey:

• Point ID and type (brass disk, iron rod, nail, cut cross, etc.)
• Coordinates, elevation, and datum/epoch
• Source of coordinates (NGS datasheet, GNSS observation, traverse adjustment, client-provided)
• Date the coordinates were determined
• Condition at the time of the current survey (found in good condition, disturbed, destroyed, etc.)
• Detailed written description of the location
• Photographs
• Ties to reference objects (measured distances to at least two nearby permanent features)

Recovery Notes

When recovering existing control points, record:

• Whether the point was found in the position described by the reference documentation.
• Any signs of disturbance (heaving, construction nearby, damaged monument).
• How the point was identified (stamping, disk number, matching description).
• Whether the position was verified by measurement (check tie, GNSS observation).

File Management and Naming Conventions#

Project File Structure

Establish a consistent folder structure for all projects:

PROJECT_NUMBER/
  FIELD/
    RAW/          Raw data files from instruments
    DC/           Data collector job files
    PHOTOS/       Field photographs
    NOTES/        Scanned field notes, sketches
  OFFICE/
    CONTROL/      Adjusted control data
    TOPO/         Topographic processing
    BOUNDARY/     Boundary analysis
    CAD/          Drawing files
    DELIVERABLES/ Final products
  CORRESPONDENCE/
  REFERENCE/      Record maps, title reports, deeds

File Naming

• Use project number as a prefix: SV2024-015_TOPO_RAW_20240215.dc
• Include the date in YYYYMMDD or MMDD format.
• Include a descriptor: RAW, ADJ, FINAL, DRAFT.
• Never use spaces in file names. Use underscores or hyphens.
• Keep file names under 50 characters when practical.

Version Control

• Never overwrite a raw data file. Raw files are sacrosanct.
• Use version suffixes for processed files: _v1, _v2, _FINAL.
• Maintain a processing log that records what was done to each file, when, and by whom.

Data Backup Procedures#

The 3-2-1 Rule

Three copies of every data file, on two different types of media, with one copy stored offsite. This is the minimum standard for protecting survey data.

Field Backup Routine

Critical Practices

• Never store data only on the data collector. Data collectors fail, get dropped in water, or are stolen from trucks.
• Never delete raw data from the data collector until it has been verified in the office and at least two backups exist.
• Cloud backup (Dropbox, OneDrive, Google Drive, or company server) should be automatic and daily.
• Test your backups. Periodically restore a file from backup to verify the process works. An untested backup is not a backup.
• Protect field books. Store completed field books in a fireproof location. Scan and digitize critical pages.

Key Takeaways#

• Field notes are legal documents. They must be complete, legible, dated, and signed. Never erase -- line through errors and write corrections.
• Sketches provide context that coordinates and codes cannot. Every survey should include field sketches showing relationships between features, reference objects, and survey points.
• Feature codes drive automated mapping. Establish a consistent, documented code library and train every crew member on it before fieldwork begins.
• Point numbering should be systematic and logical. Reserve distinct ranges for control, topographic, and boundary points. Never reuse numbers within a project.
• Photographs are essential documentation. Photograph every monument, every significant feature, and every condition that could be relevant to the survey purpose. Include scale references and identification.
• Raw data is irreplaceable. Back up immediately, back up redundantly, and never delete the original until the project is complete and archived.
• Combine electronic and manual methods. The data collector records the measurements; the field notes and sketches record the judgment, context, and observations that make the data meaningful.

References#

1. Davis, R.E., Foote, F.S., Anderson, J.M., & Mikhail, E.M. Surveying: Theory and Practice (6th Ed.). McGraw-Hill, 1981. Chapter 3.
2. Ghilani, C.D. & Wolf, P.R. Elementary Surveying: An Introduction to Geomatics (13th Ed.). Pearson, 2012. Chapter 3.
3. Kavanagh, B.F. & Mastin, T.B. Surveying: Principles and Applications (9th Ed.). Pearson, 2014. Chapter 2.
4. Anderson, J.M. & Mikhail, E.M. Surveying: Theory and Practice (7th Ed.). McGraw-Hill, 1998. Chapter 7.
5. California Board for Professional Engineers, Land Surveyors, and Geologists. "Land Surveyor Record Keeping Standards."
6. ALTA/NSPS. Minimum Standard Detail Requirements for ALTA/NSPS Land Title Surveys (2021). Table A, Items 1--20.