DJI Terra GCP Import: File Format & Marking Guide

Check the control evidence before opening the importer

Start with the survey record and point descriptions. Each identifier should refer to one clearly defined location, and the measured coordinate must describe the same target center that the operator will mark in the photographs.

• Confirm unique identifiers and remove accidental duplicate rows from the working copy.
• Record the horizontal coordinate system, units and height reference.
• Keep field notes or target photos that explain the intended center.
• Check that the targets were visible during the image capture.
• Retain the original survey export and document any formatting changes.
• Set aside suitable independently measured points for validation.

The control plan should suit the site geometry and required accuracy. This article does not prescribe one universal point count or target size. Our Accuracy, GCP & RTK guide covers the wider survey strategy.

Prepare the TXT or CSV fields and their meaning

DJI documents TXT and CSV input for visible-light GCP management. The standard manual-marking route uses a point name and three coordinate components. Custom-accuracy and certain automatic-marking scenarios require additional fields. Consult the current GCPs and Constraints instructions for the selected scenario.

Column letters alone are not enough. Some survey workflows use X for Northing; DJI’s projected-coordinate convention uses X/Easting and Y/Northing. Map by meaning, not merely by the labels in an exported spreadsheet. For geographic coordinates, explicitly identify longitude and latitude in the preview rather than assuming one universal column order.

Avoid thousands separators, mixed decimal conventions and unintended empty columns in the working file. Check how the import preview handles the chosen delimiter and any header line.

Use a simple projected-coordinate example to test parsing

The following fictitious rows illustrate a space-delimited TXT structure: identifier, Easting, Northing and height. They are not field observations and must not be used to control a real reconstruction.

GCP01 500000.125 4500000.250 72.340
GCP02 500080.750 4500030.625 73.120
CHK01 500045.500 4500085.875 72.890

Use the actual coordinate reference and height convention supplied by the surveyor. The file does not establish its reference merely because the numbers resemble a projected grid.

1. Open the working file in a plain-text viewer and inspect a few rows.
2. Confirm that each row contains the expected number of fields.
3. Set the importer’s available delimiter, decimal and header options to match the file.
4. Map the columns explicitly and inspect the parsed preview.
5. Compare an imported point with its source row before importing the complete control set.

If using CSV, take particular care where decimal commas and comma-separated columns could be confused. Use a format and parsing configuration that the current importer supports, then verify the preview rather than relying on the file extension.

The prefix CHK in this example is only a naming aid. Assign the point’s actual control or checkpoint role in Terra; its name alone does not establish that role.

Select the reference of the measured GCP coordinates

Choose the GCP coordinate system from the measurement documentation. Keep the image-position reference, control reference and output requirements understandable as separate inputs to the project.

Review the horizontal datum, projection or geographic convention, coordinate units and height system. If the client supplies a local engineering grid, obtain its definition and the applicable Terra workflow rather than substituting a nearby standard grid.

DJI’s GCP management steps instruct users to set the GCP reference and a consistent output reference. Follow the current release’s supported transformation rules; do not force incompatible definitions just to continue a reconstruction.

• Check a known horizontal position before marking every photograph.
• Confirm whether elevations are ellipsoidal, orthometric or locally referenced.
• Check that any height conversion was applied once, at the intended stage.
• Record the exact reference supplied with the control file.

For a shifted model or unexplained height difference, use our coordinate system and geoid guide. Importing valid numbers into the wrong reference remains an incorrect import.

Follow the visible-light GCP management sequence

The current manual places GCPs and Constraints under Preprocessing (AT). Its workflow connects coordinate import, aerial triangulation, image marking and optimization before final reconstruction. Consult the current Terra GCP management chapter alongside the installed release.

1. Create the visible-light reconstruction task and import the source images.
2. Open GCPs and Constraints from Preprocessing (AT).
3. Prepare aerial triangulation before marking, as recommended in the manual.
4. Import the coordinate file, set the measured reference and validate the parsed fields.
5. Assign control or checkpoint roles deliberately.
6. Mark the relevant observations in the photographs.
7. Run the supported optimization and inspect the results.
8. Select a supported output reference and reconstruct the required products.

Use a small, representative task to establish the sequence before applying it to a large delivery. Save a reviewable project revision when changing roles, coordinate settings or marks.

This sequence is not a reason to discard the original observations after optimization. Keep the survey export and any marking records with the project so another operator can understand what was used.

Mark the same physical center in suitable images

A coordinate can be correct while its image observation is wrong. Enlarge the target enough to identify the surveyed center, then mark that same physical location in each usable photograph.

• Use sharp images where the target center is visible.
• Reject ambiguous observations affected by blur, shadows, occlusion or target movement.
• Compare the target with its field description if several similar features exist.
• Avoid marking a different corner or crossing in another image.
• Review edge observations and views with difficult perspective.

The current manual recommends at least five evenly distributed GCPs in a mapping area and eight to nine image marks from different angles per GCP. These are DJI workflow recommendations, not a universal survey design or an accuracy guarantee. The older support sequence describes four marked images; use the current release’s guidance when preparing a new task.

For Auto GCP in an arbitrary coordinate system, the manual requires the corresponding WGS84 longitude, latitude and altitude in additional columns. A four-column local-coordinate file is therefore not sufficient for that specific automatic route. Check the actual method before formatting the input.

Capture quality limits what can be marked reliably. Our GSD, flight height and overlap guide and Zenmuse P1 workflow explain preparation upstream of the import stage.

Set point roles and accuracy values for a defensible review

Control points contribute to adjustment; checkpoints are reserved for evaluation in the supported workflow. Keep the role assignment visible in the project record and explain any later change.

Accuracy values should reflect the measured observation uncertainty. Entering smaller numbers is not a substitute for a better survey. An overly optimistic value can give an observation inappropriate influence relative to the other data.

RTK or PPK positioning and ground control belong to one overall accuracy plan. Their presence does not automatically eliminate the need for independent checks. Our PPK workflow guide explains the separate preparation of positioning evidence.

If a checkpoint result is poor, investigate it. Reclassifying it as control may change the model, but removes that point’s independence for evaluating the changed adjustment.

Investigate common import and marking problems

Inspect the original coordinate and a small set of observations before rerunning the entire reconstruction. Keep changes separate so the cause and effect are understandable.

Image-space residuals and real-world positional errors have different units and meanings. A visually acceptable mark or a small reprojection residual does not demonstrate the final absolute survey accuracy.

Our reconstruction troubleshooting guide covers broader task failures; this article focuses on the control-data input and observation stage.

Review and archive the accepted control workflow

Inspect the quality report, individual residuals and independent check results. Compare them with the project specification and the survey observation quality, not with an unsupported universal accuracy promise.

1. Confirm that point names, coordinates, roles and marks match the intended revision.
2. Review unusual results and document the investigation.
3. Check horizontal and vertical behavior separately.
4. Inspect the actual exported maps, surfaces or point clouds.
5. Archive source coordinates, target descriptions, marking records and quality evidence.
6. Provide the recipient with the reference and known limitations.

Use our quality report guide for interpretation. A favorable report must still be consistent with the delivered files and the independent project checks.

For repeat surveys, retain the reference record and verify whether targets remained stable and observable. Reusing a point name does not establish that its location or measurement is unchanged.

DJI Terra GCP import and marking FAQ

Can I import GCP coordinates from a CSV file?

DJI documents TXT and CSV input. Confirm the current importer’s options, map the fields explicitly and inspect the preview before using the records.

Does X always mean Easting in my survey export?

No. Confirm the source convention. DJI’s projected GCP convention uses X/Easting and Y/Northing, but a supplier may label its fields differently.

Can I use the sample coordinates in this article?

No. They are fictitious formatting examples. Use measured project coordinates and the documented reference.

How many images should I mark for each GCP?

The current manual recommends eight to nine marks from different viewing angles per point. Follow the installed workflow and the survey plan, using observations that identify the correct target clearly.

Will a CHK point name automatically create a checkpoint?

Do not rely on the name. Set and verify the actual point role in Terra.

Does a successful import prove that the survey is accurate?

No. Validate coordinates, image observations, adjustment and independent results, then inspect the delivered outputs.

Official documentation

• Current DJI GCPs and Constraints: import scenarios and marking
• DJI support guidance on GCP fields and coordinate conventions
• DJI support GCP management sequence
• DJI Terra releases, manuals and quality documentation

Independent guide by Drone Emotions. Documentation reviewed on 13 October 2026. Consult the documentation for the installed software and capture-system releases.