Aerial Mapping Systems

Klau Geomatics

Klau Geomatics builds light, efficient positioning systems for manned and unmanned aerial mapping.

Camera Positioning System

A generic PPK (post processed kinematic) camera positioning system that integrates with most cameras on any UAV or manned aircraft. PPK produces high accuracy GNSS (GPS plus Glonass) camera positions to increase photogrammetric mapping accuracy and reduce ground control requirements.

The key to accuracy in any mapping or 3D modelling project is control. This can be either GCPs (ground control points) visible in the photos, or CPs (camera positions) where each photo was taken. Enabling your mapping data acquisition with accurate CPs can reduce or eliminate the need for GCPs, saving on ground survey crew time and cost.


 How It Works

The PPK hardware operates independently of your current UAV flight management system. Your UAV will fly as it does now, with onboard flight control using the existing autonomous GPS. The PPK system logs precise carrier phase GNSS data with millisecond camera trigger events to provide highly accurate camera positions after post processing.

PPK requires base station data to process against. You will need a survey grade GNSS unit logging data in the vicinity of the project, or you can download data from a local CORS station. A base receiver can be supplied if required.

After post-processing, the high-precision camera coordinates are input into your photogrammetry software (such as Agisoft or Pix4D), along with your images. With centimetre level camera positions, the mapping and modelling you produce will have the highest possible accuracy.


Why PPK?

Typical geo-referenced UAV systems implement real time kinematic (RTK) solutions using various grades of GPS receiver. RTK requires a stable radio link to receive base station data which is processed on the fly. Particularly with UAV flight dynamics, RTK can be prone to GPS signal blockage and radio link outages. This is apparent where signals are obstructed or over long distances, where loss of correction data and initialization result in a smaller percentage of accurate camera positions being determined.

An alternative to RTK is post processed kinematic (PPK), where data is logged in the UAV and processed with base station data after the flight.  There is no data loss or initialization loss as in RTK due to radio link limitations. All collected data is processed with similar algorithms to RTK, but forwards and backwards through the data. This ensures the most robust results possible.

PPK offers greater flexibility in operations, longer range from the base, is more reliable, more accurate and easier to use.


Applications

NDVIAccurate 2D mapping with no GCPs
for Precision Agriculture

mineHigh accuracy 3D modelling
with minimal GCPs

asset inspectionAccurate asset inspections

High spec Novatel GNSS board

Triple frequency L1/L2 GPS/Glonass

  • 2cm horizontal and 5cm vertical camera position accuracy after processing with base station data (no radio link required).
  • reduce or negate ground control survey requirements.
  • produce highly (absolute) accurate DTMs and georeferenced orthos
  • Lightweight UAV version or ruggedised metal enclosure with additional outputs for manned aircraft.

Compatibility

UAVs

  • Compatible with fixed wing and multirotor UAVs.
  • Inputs to the system are power and camera trigger events (flash signal)
  • Requires power from UAV via splice connector to battery or  balance charge connector.
  • PPK box to be installed on UAV so as not to obstruct flight control GPS antennae.
  • Antenna to be mounted directly above center of camera

Manned Aircraft

  • Proven in fixed wing and helicopter mapping operations
  • Integrates with Aviatrix flight control system
  • Powered from internal battery
  • Antenna requires aviation authority approved installation

Cameras

  • Compatible with any COTS DSLR camera with flash hotshoe or PC port
  • Independent of any flight management and camera triggering system
  • Camera events are read via the camera PC port or generic hot-shoe
  • Tags timing of center of exposure to raw GNSS data stream
  • Compatible with most DSLR cameras including Sony, Nikon and Canon
Base Station

  • Process with Rinex data from a known base station
  • Use your own survey grade GNSS receiver or purchase our dedicated base model
  • Process with Rinex data from a nearby CORS station
  • Use satellite broadcast corrections such as Omnistar or Terrastar

Models
UAV Manned Base Station
L1 L2 GNSS L1 L2 GNSS L1 L2 GNSS
by Novatel by Novatel by Novatel
Lightweight Ruggedized 5/8 mount
200g 500g 500g
light active antenna Aviation approved active antenna active antenna
USB and serial outputs

Post Processing Software
PPK software screenshot

Dedicated, custom developed software for PPK post processing and extracting photo centres from post processed data. The software runs forward and backward processing for smooth and precise results.

Result

Software supplied free with hardware.


Accuracy
  • Dependent on distance from base station
  • Camera position accuracy 3cm horizontal and 5 to 10cm vertical plus 1ppm
  • Aircraft flight dynamics contribute to absolute camera position accuracy.
  • For orthomosaic generation (2D), no GCPs are required
  • 2 or 3 GCPs are recommended for accurate 3D modelling (to 5cm) to manage camera
    focal length errors

Manned Aircraft Flight Management System and Mission Planning
Complete flight control including terrain assisted mission planning, interactive smart pilot interface and automated camera triggering.

flight controller

  • proven software developed in Australia
  • integrated into onboard computer

integrated computer

  • flight control with pilot display
  • integration to autopilot
  • data logging

flight_plan_920

cockpit


 

Klau Geomatics

PO Box 277, Ulladulla, NSW, 2539 Australia

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