Project Background & Details
While planning to add a LiDAR System to its fleet of sensors, HIPARC decided to acquire a GeoLas ELMAP30-V LiDAR system which was installed into a Piper Aztec aircraft along side a Vexcel Ultracam Lp.
One of the most important reasons to choose the ELMAP LiDAR was it’s 80° Field of View which allows to constantly produce a 50% overlap in the LiDAR data while using the smaller Field of View of the Vexcel camera.
The challenge in this particular installation was to control the LiDAR system from the Ultracam and its LeadAir flight management system using the TECI system/sensor interface box of the TrackAir flight management system. The Installation itself was straight forward due to the highly flexible control interface of the ELMAP sensor which provides multiple external control inputs.
The ELMAP series LiDAR scanners are made for high-altitude, high-efficiency mapping. City-scale LiDAR projects are easily achievable with swath widths reaching 5,150 m. Selectable measurement rates up to 1600 kHz and line speed up to 250 per second can be tuned to meet challenging point density specifications.
ELMAP30-V System Specifications
The ELMAP30-V has an industry-leading field-of-view of 80° and with up to 1′ 400’000 shots-per-second on the ground an outstanding puls repetition rate. The LiDAR is capable of measuring at a high range of 4’300m at 20% target reflectance. The full LiDAR specifications can be found here: ELMAP-V – GeoLas Systems
Additionally Integrated Subsystems
The goal was to integrate the LiDAR with the Vexcel camera and the LeadAir Teci flight management system as well as a GNSS/IMU system. The LiDAR system finally was installed using the following subsystems:
GNSS/IMU Solution NovAtel CPT 7700
The HG4930 IMU combined with the multi-frequency CPT 7700 OEM GNSS receiver offers future-ready precise positioning for all aerial sensor applications. The entire GNSS/IMU solution was completely installed into the IMU compartment box which is part of the ELMAP30-V LiDAR sensor.
Flight Planning and Management System
The TrackAir flight management system from LeadAir is a commonly used system around around the world including flight planning and management tools used in combination of all kind of aerial sensors such as aerial cameras and LiDAR systems. LeadAir’s TECI interface computer is a plug and play system designed to make flight management, sensor triggering and mount control possible.
Vexcel Ultracam Lp
The Vexcel Ultracam Lp is a 92 Mp digital aerial camera incorporates TDI controlled CCD sensors for panchromatic and colorized image data acquisition.
Camera Mount
The camera is mounted on a LeadAir camera mount while the ELMAP LiDAR system has a fixed mount in a separate aircraft hatch.
Final ELMAP30 Installation in a Piper Seneca II Aircraft
HIPARC Sistemas’
Piper Aztec
Dual Hatch Installation of GeoLas ELMAP
& Vexcel Ultracam
ELMAP30-V LiDAR System
mounted in the aircraft
Dual Sensor Data Collection for System Check and Boresight Calibration
LiDAR and image data collection are synchronized so that, with the camera’s 57° field of view (FoV), the ELMAP, having an 80° FoV, achieves a predetermined 50% overlap for LiDAR data collection. For the LiDAR a separate IMU was installed to ensure highest LiDAR data quality.
Below are various point density scenarios:
LiDAR Point Density
GSD Vexcel UC Lp
LiDAR Pulse Rate
Aircraft Speed
Flying Altitude
30 pts/m² single path
50 pts/m² dual path
5cm
1’600 kHz
100 kn
1’900 ft AGL
8 pts/m² single path
14 pts/m² dual path
10cm
850 kHz
120 kn
3’800 ft AGL
0.6 pts/m² single path
1 pts/m² dual path
20cm
170 kHz
130 kn
7’600 ft AGL
Test Flight
A test flight was conducted successfully to ensure the LiDAR System together with the flight management and the Vexcel Camera are working smoothly together which could be confirmed right after the flight. The test flight was flown at three different altitudes of 580m (1’600 kHz), 1’160m (850 kHz) and 2’340m (170 kHz) AGL.
Data Processing for Boresight Calibration
In addition a boresight calibration flight was planned and flown to generate the DSM for the LiDaR system boresight calibration. Both flights were part of the HIPARC acceptance process and done successfully.
Flight Details
The test and calibration flight was flown at 530m flying altitude AGL with a spedd of 100 knots.
LiDAR Pulse Rate
The LiDAR sensor pulse rate varies from 100 kHz to 1’600 kHz pulse repetition frequency, allowing for high-resolution data collection. This high emission frequency is crucial for capturing detailed surfaces and features and can be perfectly aligned with the required camera GSD. For the test flight a pulse rate of 1’600 kHz was chosen.
Point Density
For the test and calibration flight a point density of 25 points per square meter was achieved.
The GeoLas ELMAP Series
The ELMAP LiDAR systems are state-of-the-art mid- to high-range LiDAR sensors designed for integration in manned fixed-wing and helicopter aircraft, gyrocopters, ultralight aircraft, and heavy-lift drones. They are built to withstand the harshest environments and offer unparalleled performance and ease of use.
Highlights:
- Compact all-in-one mapping systems
- Huge 80° field-of-view
- Linear uniform scan pattern with parallel scan lines
- Integrated removable data storage on standard SSDs
- Waveform digitization for every pulse
More details on the ELMAP-V can be found here: ELMAP-V – GeoLas Systems
Data Samples
The data captured included detailed imagery and LiDAR data to produce high-resolution data. The data collection flights were meticulously planned to cover the specified areas to achieve the required data.
Digital Surface Model
Intensity Image
RGB Camera Image
Summary
The system is designed to deliver a seamless data flow that integrates every step of the workflow, from initial mission planning to data processing and final analysis. This streamlined process minimizes inefficiencies and ensures smooth transitions between stages, enabling accurate and efficient calibration. In the planning phase, precise flight paths and parameters are established to optimize data capture, whilst during data processing, advanced tools automatically handle data alignment, filtering, and correction, ensuring high-quality outputs. Hence, the comprehensive and unified workflow significantly improves operational efficiency and ensures reliable results for geospatial and mapping projects. Additionally, the installation was extremely quick and straightforward, ensuring minimum time to setup and smooth operation.
“HIPARC Sistemas is delighted to welcome the newly delivered ELMAP30-V to its fleet of production sensors. We chose GeoLas as our supplier for its outstanding specifications and the seamless workflow it offers, from flight planning to data processing, ensuring perfect integration with our Vexcel Ultracam camera and our current flight management system.”, says Flavio Martins, CEO of HIPARC Sistemas.
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