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Topsy Creek Autonomous Hydrographic Survey
CLIENT
Tailored Spatial Solutions
REGION
Topsy Creek, Queensland
FIELDWORK
28-30 November 2025
QOFFSHORE ROLE
ASV hydrographic survey
SERVICE
River-mouth MBES
SURVEY AREA
397,667 m²
RESOLUTION
0.25 m bathymetric grid
OUTPUTS
DTM, contours, spot depths & report
The client issue
Tailored Spatial Solutions required detailed bathymetry through Topsy Creek, its river mouth and approaches to support engineering assessment, operational planning and future maintenance. The waterway was shallow and geographically remote, making a compact, self-contained survey platform well suited to the task.
The practical question
How can a shallow, remote waterway be mapped efficiently while maintaining dense coverage, precise positioning and dependable depth accuracy?
The survey challenge
Shallow, winding waterway
The survey corridor followed a narrow creek and river mouth where larger survey craft would face tighter access constraints.
Remote mobilisation
Personnel and equipment were flown to site, while satellite positioning corrections avoided dependence on local RTK infrastructure.
Engineering-grade QA/QC
High-density bathymetry still needed defensible uncertainty, calibration and repeatable georeferencing across the full route.
What QOffshore provided
Working for Tailored Spatial Solutions, QOffshore mobilised a Unique Uni-Mini autonomous surface vessel with a NORBIT iWBMS multibeam system and POSMV INS with dual Trimble GNSS antennas. Fugro MarineStar G4+ corrections supported positioning, with Qinsy used for acquisition and Qimera for processing and QA/QC.
Mobilise the ASV
Mobilise the ASV Fly the team and equipment to site, assemble the platform and confirm sensor offsets and readiness.
Calibrate and position
Complete the MBES patch test and establish the satellitecorrected positioning workflow.
Acquire dense coverage
Run planned MBES lines through the creek and river mouth with overlap and real-time coverage checks.
Process and report
Clean and validate soundings, quantify uncertainty and deliver DTM, contours and spot depths.
397,667 m²
SURVEY AREA
376.8 million
ACCEPTED SOUNDINGS
0.25 m
GRID RESOLUTION
+/-0.08 m
DEPTH UNCERTAINTY
DECISION-READY OUTPUTS
- 0.25 m high-resolution bathymetric surface
- DTM and contour chart series
- Spot-depth chart series
- Hydrographic uncertainty and QA/QC assessment
- Engineering and navigational assessment dataset
Outcome and client value
The survey achieved dense bathymetric coverage across almost 0.40 km² and reported a depth uncertainty of approximately +/-0.08 m. The resulting high-fidelity surface was considered suitable for engineering and navigational assessment, while the compact ASV provided a practical acquisition platform for the shallow-water corridor.
THE SUCCESS STORY
QOffshore combined remote mobilisation, autonomous acquisition and rigorous QA/QC to produce engineering-grade bathymetry from a shallow, difficult-access waterway.
