50cm vs 100cm vs 150cm Ground Control Point (GCP) Target – Which Size for Drone Survey Malaysia?
50cm vs 100cm vs 150cm Ground Control Point (GCP) Target – Which Size for Drone Survey Malaysia?
Content
50cm vs 100cm vs 150cm GCP Target for Drone Survey Malaysia
How to Choose the Right Ground Control Point Size for UAV Mapping & Photogrammetry
Should you use a 50×50cm, 100×100cm or 150×150cm Ground Control Point (GCP) target for drone surveying?
The answer depends mainly on whether the target can be clearly and consistently identified in the aerial imagery under your actual flight conditions.
MTM Precision supplies three reusable GCP target sizes:
• 50 × 50 cm — Compact
• 100 × 100 cm — General Purpose
• 150 × 150 cm — Large & Highly Visible
QUICK ANSWER: For general drone surveying, 100×100cm is a practical all-round starting size. Choose 50×50cm when portability matters and image resolution is sufficient, while 150×150cm is useful when a larger visual target is required.
GCP Size Comparison at a Glance
Size50×50cm100×100cm150×150cmGround footprintSmallMediumLargePortabilityExcellentVery GoodModerateStorageEasiestEasyMore spaceDeploymentFastFastLarger area requiredVisual sizeSmallestBalancedLargestGeneral-purpose useGood*Recommended starting pointApplication dependentBest characteristicPortabilityBalanceVisibility
*Subject to sufficient visibility at the project's GSD and flight parameters.
There is no single “best” GCP size for every drone survey. The correct target is one that can be reliably identified without compromising the accuracy of marking its reference point.
50×50cm GCP – When Should You Use It?
The 50×50cm Ground Control Point is attractive because it is compact.
For a survey team carrying several GCPs into the field, this can make deployment considerably easier.
Main Advantages
✓ Small and portable
✓ Easy to carry in a vehicle
✓ Easy to deploy and collect
✓ Convenient when many targets must be transported
✓ Suitable where imaging conditions provide sufficient visibility
Potential applications include:
• Small construction sites
• Smaller land parcels
• Suitable low-altitude drone mapping
• Localised surveys
• Building projects
The Limitation of a 50cm GCP
A small target occupies fewer pixels as the effective ground sampling distance becomes coarser.
That means:
A 50×50cm target that looks extremely obvious while standing beside it may become difficult to identify once viewed from the drone's mapping imagery.
This is why buyers should not choose the smallest GCP purely because it is cheaper or easier to carry.
Consider:
Flight Height + GSD + Camera + Target Contrast + Ground Surface
before deciding.
100×100cm GCP – The General-Purpose Choice
For many users, the 100×100cm GCP target provides the most practical compromise.
It is substantially larger than a 50cm target while remaining manageable for field transportation.
Why Consider 100×100cm?
✓ Good balance between visibility and portability
✓ Practical for repeated field use
✓ Suitable for many construction projects
✓ Useful for earthwork and topographic mapping
✓ Easier to identify than a smaller target under comparable imaging conditions
If a customer asks MTM Precision for one general-purpose GCP size without a specific project requirement, 100×100cm is the size we would normally evaluate first.
Where Can 100×100cm GCP Targets Be Used?
Typical applications include:
CONSTRUCTION SURVEY
Progress mapping and site documentation.
EARTHWORK SURVEY
Terrain modelling and volume-related mapping workflows.
TOPOGRAPHIC MAPPING
Supporting georeferenced UAV mapping.
ROAD & INFRASTRUCTURE
Mapping suitable project areas and corridors.
QUARRY SURVEY
Surface mapping and volume-related workflows.
LAND DEVELOPMENT
Mapping larger development sites.
PLANTATION MAPPING
Aerial mapping across agricultural and plantation environments.
150×150cm GCP – When Bigger Visibility Is Needed
The 150×150cm GCP provides three times the side length of the 50cm version and therefore a much larger ground footprint.
Its principal advantage is simple:
It creates a larger feature for the drone camera to see.
This can be useful for applications where a larger target is desirable because of the planned imaging conditions.
Potential applications include:
• Large construction projects
• Open earthwork sites
• Quarry mapping
• Plantation mapping
• Infrastructure projects
• Larger survey areas
Does a 150cm GCP Give Better Accuracy?
NO — not automatically.
This is one of the most important points when selecting GCP targets.
Target size and survey accuracy are not the same thing.
A larger target may improve visibility, but final positional accuracy can also depend on:
• Accuracy of the surveyed GCP coordinates
• GCP distribution
• Number of control points
• Check Point configuration
• Flight geometry
• Image overlap
• Camera characteristics
• GNSS solution quality
• Photogrammetry processing
Do not buy 150×150cm simply because “bigger must be more accurate.” Buy it when your project benefits from a larger identifiable target.
GCP Size and Ground Sampling Distance (GSD)
GSD is one of the key concepts to understand.
Ground Sampling Distance describes approximately how much ground area is represented by one image pixel.
For example, if the effective GSD is approximately:
2 cm/pixel
then, in an ideal simplified case:
50cm target ≈ 25 pixels across
100cm target ≈ 50 pixels across
150cm target ≈ 75 pixels across
If the GSD becomes:
5 cm/pixel
then approximately:
50cm target ≈ 10 pixels across
100cm target ≈ 20 pixels across
150cm target ≈ 30 pixels across
This simple example shows why GSD is more meaningful than saying “this GCP is suitable for X metres altitude.”
Flight altitude alone is not enough because different drones, sensors, lenses and image settings produce different GSDs.
Don't Choose GCP Size by Flight Height Alone
You may see recommendations such as:
“50cm GCP for 50m flight”
or
“100cm GCP for 100m flight.”
These can be convenient rules of thumb, but they should not be treated as universal specifications.
Two drones flying at the same height can produce different imagery because of differences in:
• Sensor size
• Resolution
• Focal length
• Camera orientation
• Image quality
For professional selection, consider the resulting GSD and target visibility—not flight altitude alone.
Target Contrast Is Also Important
Size is only one part of GCP visibility.
A large target with poor contrast against the surrounding ground may still be harder to identify than expected.
Consider the background:
Dark asphalt
Light concrete
Red soil
Grass
Sand
Quarry surfaces
Construction earth
A strong contrast between the GCP pattern and surrounding surface helps make the target easier to locate in aerial imagery.
Where Should the Exact GCP Coordinate Be Measured?
This is extremely important.
The survey coordinate should correspond consistently to the defined reference point of the target, normally its clearly identifiable centre/reference mark according to the target design and survey methodology.
The point you measure on the ground must correspond to the point you mark in the aerial photographs.
A huge target is of limited value if its reference point cannot be identified consistently.
GCP Size vs GCP Quantity
Another common misunderstanding is:
“If I use bigger targets, I need fewer GCPs.”
Not necessarily.
Target size affects visibility.
GCP quantity and distribution affect the control geometry.
They solve different problems.
A project may require multiple well-distributed control points regardless of whether the physical targets are 50cm, 100cm or 150cm.
Which GCP Size for Construction Survey?
For general construction mapping:
100×100cm is a strong starting option.
It offers good portability while providing a larger visual target than the compact 50cm version.
For projects where smaller targets remain clearly visible, 50×50cm may be sufficient.
Where a significantly larger visual target is beneficial, consider 150×150cm.
Which GCP Size for Quarry Survey?
Quarries can involve:
• Large open areas
• Elevation changes
• Similar-looking ground surfaces
• Stockpiles
• Large earthwork zones
A 100×100cm or 150×150cm target may therefore be worth considering depending on the mission parameters and required visibility.
Which GCP Size for Plantation Mapping?
Large plantation or agricultural sites can create different challenges:
• Large coverage area
• Vegetation
• Uneven terrain
• Limited clear ground locations
Where appropriate clear placement locations are available, a larger target such as 100×100cm or 150×150cm may provide stronger visual presence.
Which GCP Size Should a New Drone Surveyor Buy?
If you are starting drone mapping and want reusable GCPs:
START WITH 100×100CM
Why?
Because it provides a practical middle ground between:
50cm — easier to carry but smaller
and
150cm — larger visual target but bulkier
As you gain experience with your actual drone, GSD and project types, you can add smaller or larger targets when required.
Can I Mix Different GCP Sizes on One Project?
Potentially, yes, provided the targets are appropriate for the survey methodology and each reference point can be identified reliably.
However, there is normally value in maintaining a consistent target design and clearly defined reference point across the project.
For survey teams handling many different projects, keeping more than one physical size available can provide greater flexibility.
Quick Buying Recommendation
Choose 50×50cm if:
Your priority is portability and your imaging conditions provide sufficient target visibility.
Choose 100×100cm if:
You want the most versatile general-purpose option.
Choose 150×150cm if:
You need a larger visual ground target for your application.
Frequently Asked Questions
Is 50×50cm too small for drone surveying?
Not necessarily. Suitability depends on GSD, image quality, target contrast and the project's requirements.
Is 100×100cm the best GCP size?
There is no universal best size, but 100×100cm provides a practical balance for many general applications.
Is 150×150cm more accurate?
No. A larger target mainly increases visual size. It does not automatically increase coordinate or mapping accuracy.
Can RTK drones use these targets?
Yes. GCPs and/or independent Check Points can be incorporated into RTK drone workflows depending on project requirements.
Can I use a Total Station to survey the GCP?
Yes. The GCP reference coordinate can be established using an appropriate professional surveying method, including GNSS/RTK or Total Station workflows.
Buy 50cm, 100cm & 150cm GCP Targets in Malaysia
MTM Precision supplies reusable Ground Control Point Targets for Drone Survey in Malaysia.
Available Sizes
50 × 50 cm — Compact
100 × 100 cm — General Purpose
150 × 150 cm — Large Target
Suitable for UAV Mapping, Photogrammetry, Construction, Earthwork, Topographic Survey, Quarry Mapping, Infrastructure and Plantation applications.
Contact MTM Precision
MTM Precision Sdn Bhd
Website: www.mtmpre.com.my
Email: mtmpre@yahoo.com
WhatsApp: 016-660 7346
Showroom & Service Centre
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia.
Serving Selangor, Kuala Lumpur, Johor, Penang, Perak, Negeri Sembilan, Melaka, Pahang, Kedah, Perlis, Terengganu, Kelantan, Sarawak and Sabah.
08 Sep 2026
