High-accuracy RGB camera for surveys with fewer GCPs
High accuracy with fewer GCPs, proven in the field
In traditional photogrammetry, Ground Control Points (GCPs) compensate for cumulative errors introduced by camera geometry, image timing, and positioning uncertainty.
SURVEY61 reduces several of these dominant error sources at capture through:
- a high-resolution 61 MP sensor
- low-distortion optics
- a mechanical shutter
- precise PPK positioning
SURVEY61 vs terrestrial scanner
On a 20 ha (40 ac) stockpile survey, SURVEY61 delivered nearly the same result as a Trimble SX10. The total volume difference was just 0.24 m3, and the average surface difference was 2.6 cm.
SURVEY61 accuracy white paper
The SURVEY61 accuracy white paper covers 102 flights across 5 test sites. The results show consistent sub-3 cm (0.1 ft) accuracy using checkpoints only.
Survey faster with fewer targets to place
- 6x faster field work*
- Save 60% on labor costs
- Keep your teams safe from hazard on active sites
*6x less time spent in the field compared to traditional multicopter workflows, achieved through shorter flight and reduction of time spent on ground target placement.
Survey active sites without waiver and without stopping work
Pair SURVEY61 with WingtraRAY and the parachute add-on add-on to map active construction sites, roads and populated areas with fewer delays.
WingtraRAY supports legal operations over people (OOP) in many standard US survey scenarios. That helps teams collect aerial survey data without shutting down work on the ground or waiting through long waiver processes.
For high-frequency, repeatable data
Get survey data in time for key earthworks decisions
Earthworks teams need current surface data before key decisions, not after crews have already moved on.
SURVEY61 helps teams capture frequent, high-accuracy data for bids, progress checks, cut-and-fill reviews and payment discussions.
With fewer GCPs to place and measure, crews can survey more often without turning each update into a major field task.4
Keep mine and stockpile data current
Mine survey teams need accurate volumes and current site surfaces. But frequent surveys can slow down operations when crews need to place targets, drive across active areas or work near equipment.
SURVEY61 helps teams collect high-accuracy RGB data more often, with fewer GCPs in many workflows.4
That makes it easier to update stockpile volumes, track pit changes and support production planning without exposing crews to unnecessary site risk.
- Stockpile volume measurement
- Pit and quarry mapping
- Short-interval change detection
- Haul road and active area updates
What survey teams say in the field
WingtraRAY with the SURVEY61 matches all my earthworks requirements: Accurate data repeatedly, SORA compliance, excellent support, and an efficient and easy to use workflow for my team.
SURVEY61 tech specs
at 120 m (400 ft) flight altitude
at 1.3 cm/px (0.51/px) GSD
Including set up time, with 3 check points, preflight checks, flight with 1 mile VLOS. SURVEY61 @ 0.5 in/px (400 ft), 70% side, 70% front, 22 m/s flight speed
with PPK
at 46 m AGL (150 ft)
Other sensors
FAQ
How can SURVEY61 reduce GCPs without losing accuracy?
Ground control points (GCPs) have a clear job. They help constrain the photogrammetric model during processing. That can improve accuracy when the source data needs correction or when the project requires a defined control workflow.
But GCPs do not independently prove that the final deliverable is accurate. A point used to adjust the model cannot also serve as a clean, independent check of that same model.
Checkpoints do a different job. They stay out of the adjustment. After processing, the surveyor compares each checkpoint’s measured ground coordinate with the coordinate in the final map, surface or point cloud. That comparison shows whether the deliverable matches ground truth within the required tolerance.
SURVEY61 improves the source data before processing. Its 61 MP full-frame sensor, mechanical shutter, low-distortion optics and precise post-processed kinematic (PPK) positioning reduce several major error sources at capture. This helps many repeat survey workflows use fewer GCPs while keeping independent checkpoint validation in place.
In Wingtra’s repeat accuracy study, WingtraRAY with SURVEY61 achieved consistent sub-3 cm (0.1 ft) results across 102 flights and 5 test sites using checkpoints only. The study also covers baseline distance, ground point placement and when to reduce ground control while maintaining high accuracy.
A reduced-GCP workflow works best when:
- The project does not require a fixed number of GCPs
- The team uses a reliable PPK workflow
- The correction source or base station stays close enough for the required accuracy
- The coordinate system is well understood
- The site has stable, visible surfaces for checkpoint placement
- The workflow supports repeat surveys, progress tracking, volume checks or surface comparison
- Each deliverable is validated against independent checkpoints
GCPs still belong in the workflow when:
- The project specification requires them
- The client, regulator or licensed surveyor requires a specific control method
- The deliverable carries legal, contractual or high-risk responsibility
- The site has difficult photogrammetry conditions
- The coordinate system is complex or poorly defined
- The correction source is too far away for the required absolute accuracy
- Stable checkpoint placement is difficult
- The team needs extra control for long corridors, large elevation changes, water-heavy areas or other complex sites
With SURVEY61, teams can reduce unnecessary ground control in suitable workflows, validate each result with checkpoints and spend less time placing targets across active sites.
When do I need GCPs and when do I use a GCP-free workflow?
Context
- Ground Targets can be used either as Ground Control Points (GCPs) where they are used in photogrammetry to actually tie in the map to your Ground Target locations. Or they can be used as Check Points (CPs) just for accuracy validation.
- An accurate drone solution like WingtraRAY + SURVEY61 allows you to get repeatedly to 0.1 ft or 3 cm vertical accuracy without the use of GCPs. This means that you can work with just CPs or without Ground Targets at all.
What does that mean for my project?
- For all projects where accuracy matters, working with CPs for accuracy verification is recommended. We recommend placing 3+ CPs for accuracy verification.
- For projects, where a license surveyors stamp is required, or for high-stake projects, where you need additional redundancy and a fallback in case something would be off, a higher number of well-placed Ground Targets is recommended. You can use them as GCPs or CPs if they are well placed. Using highly accurate Ground Targets as GCPs can even improve your map accuracy.
- If accuracy does not matter, you can skip Ground Targets altogether.
What is survey-grade accuracy
Survey-grade accuracy is not a universally standardised term. We use it, like many surveyors, for maps with an absolute accuracy of less than 0.1 ft (3 cm).
An absolute accuracy of 0.1 ft (3 cm) means that the x, y and z coordinates of a point in your deliverable, in a local projected coordinate system of your choice, is less than 3 cm off to it’s true location. We assess this through the RMSE in x, y and z over a number of independent Check Points.
SURVEY61
1 Maximum coverage at 120 m (400 ft) and 60% overlap
2 Achievable when following Wingtra’s recommended workflow: flying Wingtra drones with built-in GNSS PPK, using WingtraGROUND or a survey-grade base station within 10 km, and processing in Wingtra software. Accuracy assessed on independent checkpoints.
3 at 46 m AGL (150 ft)
4 Reduced-GCP workflows work best when the project does not require a fixed GCP layout, the team uses reliable post-processed kinematic (PPK), the correction source stays close enough for the required accuracy, the coordinate system is well understood and the site has stable, visible checkpoint locations. Use GCPs when project specifications, client requirements, regulators or a licensed surveyor require them, or when site conditions add risk, such as long corridors, large elevation changes, water-heavy areas, complex or poorly defined coordinate systems, distant correction sources or limited stable checkpoint placement.
Parachute and compliance
5 The WingtraRAY parachute add-on is required to enable both US Cat. 3 OOP certification and EASA C6 certification. With Cat. 3 OOP, WingtraRAY can legally fly over people and moving vehicles in the US—covering 98% of land without a waiver. In Europe, C6 certification qualifies WingtraRAY for EASA’s STS-02 scenario, allowing BVLOS flights with airspace observers without a full risk assessment (SORA). The parachute also unlocks faster approvals in high-value urban and infrastructure projects with the MOC 2512 & 2511 compliance.
The drone and parachute add-on can be purchased together or separately. The parachute add-on can be installed at any time.
Cat 3 OOP approval in the US, and C6 and C3 marks in Europe have been granted.
6 Operational limitations are dependent on your authorisation, but WingtraRAY’s parachute module and compliance evidence enables authorisations that are not possible with most drones.
7 WingtraRAY with the parachute qualifies for SORA permits using MOCs 2512 and 2511. This enables simplified compliance and unlocks flight approvals for urban projects.
8 WingtraRAY is C3 certified, qualifying it for Open Category flights without permits under EASA rules.
9 With C6 certification, WingtraRAY will support standard scenario STS-02 declarations for BVLOS flights with airspace observers.