Data Collectors and Field Software

What a Data Collector Does

A data collector (also called a field controller) is a ruggedized handheld computer that runs field survey software and communicates with a total station. Instead of writing angles and distances in a field book by hand, the collector stores every observation digitally, attaches a feature code to each point, and organizes everything into a structured job file that the office software can read without re-entry. Common units you will use in this program are the Trimble TSC series running Trimble Access and the Leica CS series running Leica Captivate. The principles are the same across brands.

Pairing the Collector to the Total Station

Most modern total stations communicate over Bluetooth or a direct USB/serial cable. Bluetooth is preferred in the field because a cable creates a trip hazard when the instrument is on a tripod.

Bluetooth pairing procedure (general):

1. Enable Bluetooth on both the total station and the collector.

2. On the collector, search for available devices and select the instrument by its serial number or assigned name.

3. Enter the PIN if prompted (check the quick-start guide for the default).

4. Confirm two-way communication by triggering a test measurement from the collector screen — the instrument should rotate or measure and the result should appear on the collector display.

Cable pairing: Connect the manufacturer cable to the correct port on each device, match the baud rate in both devices' communication settings, and test the same way.

Safety note: When working near the total station on a tripod, keep the instrument tribrach locked and stand clear of the rotating telescope. Do not place the cable where co-workers or you might trip — route it or tape it down. On elevated or unstable ground, use a hard-hat and high-visibility vest.

Anatomy of a Job File

Field software stores data in a job file (the exact file extension varies by platform). Inside every job file, records are organized by type:

• Job header: Project name, date, operator name, coordinate system, and units. This record is created when you name and open the new job.
• Setup record: The instrument point number, its known coordinates, the instrument height (HI), the backsight point number or azimuth, and the target height (HR). If any of these values are wrong, every observation in the job is wrong.
• Observation record: For each measured point — the point number, the horizontal angle, the vertical angle, the slope distance, the target height, and the feature code. The collector calculates and stores the X, Y, Z coordinates from these raw values.

Understanding record types lets you audit the raw file on the collector screen and catch errors before you leave the field.

Creating a New Job

1. Open the field software and select New Job.

2. Enter a descriptive name (e.g., `SMITH_TOPO_2025-06-10`). Avoid spaces; use underscores.

3. Set units (US Survey Feet or meters), coordinate order, and angular units (degrees-minutes-seconds).

4. Save and enter the Station Setup routine.

5. Key in the instrument point number and its known Northing, Easting, and Elevation (control coordinates from your project data).

6. Measure and enter the instrument height (HI) — measured vertically from the control nail or monument to the trunion axis mark on the instrument.

7. Enter the backsight point number (with its known coordinates) or a direct backsight azimuth.

8. Sight the backsight, confirm the angular difference between measured and computed azimuth is within your allowable tolerance, and accept the setup.

Feature Codes

A feature code (also called an attribute code or description code) tags each point with what it represents: `EP` for edge of pavement, `TBC` for top-back of curb, `BLD` for building corner, `TREE` for tree center, and so on. Your office CAD or GIS software reads these codes to draw linework automatically or populate attribute tables. A misspelled or blank feature code means manual cleanup later — or a completely wrong map. Use only codes from the project's code library, and verify spelling before you accept each observation.

Collecting the 10-Point Survey

Once the setup is accepted:

1. Start the Survey or Measure Points routine.

2. For each point: aim at the prism, enter the target height, enter the feature code, confirm the point number is sequential, and press Measure (or equivalent).

3. After the instrument measures, review the displayed coordinates on screen — do the values look reasonable given the site geometry?

4. Accept and move to the next point.

5. After all 10 points, perform a backsight check: re-sight the backsight and record the closing angular error. Note this value in your field notes.

Reviewing Raw Data and Catching Errors

Open the job's raw data view (sometimes called the Raw File or Job Data viewer). Scroll through and verify:

• The job header shows the correct project name, date, and coordinate system.
• The setup record shows the correct instrument point, HI, and backsight azimuth.
• Each observation record has a point number, non-zero distances, a valid target height, and a recognizable feature code.

Common errors that cause office processing failures: a target height left at zero when it was not actually zero; a duplicate point number; a feature code that is blank or uses a character the office software cannot parse (such as a slash or comma); or a backsight azimuth entered in decimal degrees when the software expected degrees-minutes-seconds. Flag any suspect record with a note before you download.