Since March 2008, the Swissphoto Group owns a state-of-the-art laser scanner of the newest generation. The new ALTM Gemini manufactured by the market leader Optech, Canada enables the Swissphoto Group to handle future projects even more flexible than ever before.
The main system components of the ALTM Gemini are:
- The laser system (top image) capable of emitting and receiving up to 167’000 pulses per second and integrated positioning and orientation system (POS, consisting of GPS antenna/receiver and an IMU)
- Revolutionary multi-pulse technology (enables to get simultaneously multiple laser pulses in the air), which means to have an increased point density as well as flight altitude at a higher accuracy level.
Beyond the new system the existing and proven laser scanner/digital camera system ALTM 3100 will be further employed. This system is on duty since 2005.
The main system components of the proven ALTM 3100 are:
- The laser system (middle image) capable of emitting and receiving up to 100’000 pulses per second and integrated positioning and orientation system (POS, consisting of GPS antenna/receiver and an IMU)
- A digital camera with 4’080 x 5’440 pixels and a CCD resolution of 0.009 mm
- The planning, navigation and monitoring software for in-flight management of the system
After all and since the year 2000, the Swissphoto Group has scanned more than 100'000 km2 in Germany, Austria, Switzerland, France, Italy, Luxemburg, Senegal and Liberia including processing of the raw data. The systems can be deployed in both fixed-wing aircrafts (e.g. Cessna 208,Cessna 404, Cessna 206, Pilatus Porter PC6) and helicopters (Bell 407, Eurocopter 120 B Colibri, Robinson R44). Its high reliability guarantees a high degree of availability.
The two laser scanner systems allow flying altitudes between 80 m and 4’000 m above ground. This high-end sensor systems have its counterpart in the sophisticated procedures for data analysis and quality control developed and implemented at Swissphoto.
With these universal “Airborne Sensor Systems” for combined laser and image acquisition, BSF Swissphoto is capable of offering all services concerning acquisition, processing and analysis of 3D objects
(terrain and surface models, building models, vegetation, power line features etc.) for both wide-area and corridor applications.
Technical Data Laser Scanner System
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|
ALTM3100 |
|
ALTM Gemini |
Operating altitude |
|
80 - 3'500 m over Ground |
|
150 – 4’000 m over Ground |
Horizontal accuracy |
|
1/2000 x flight altitude |
|
1/5’500 x flight altitude |
Elevation accuracy |
|
|
|
< 5 cm @ 0.5 km flight altitude |
|
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< 15cm @ 1.2 km flight altitude |
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< 10 cm @ 1.0 km flight altitude |
|
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< 25cm @ 2.0 km flight altitude |
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< 15 cm @ 2.0 km flight altitude |
|
|
< 35cm @ 3.0 km flight altitude |
|
< 20 cm @ 3.0 km flight altitude |
Laser repetition rate |
|
33 - 100 kHZ |
|
33 – 167 kHz |
Scan frequency |
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max. 70 Hz |
|
max 100 Hz |
Scan angle |
|
variable, 0 bis ± 25° |
|
variable, 0 bis ± 25° |
Range measurement |
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1 resolution, up to 4 measurements per pulse |
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1 cm resolution, up to 4 measurements per pulse |
Beam divergence |
|
0.3 mrad or 0.8 mrad (1/e) |
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0.25 mrad (1/e) or 0.8 mrad |
Intensity capture |
|
12 bit per Measurement |
|
12 bit per Measurement |
Position/Orientation System |
|
Trimble GPS and Applanix POS-AV |
|
Trimble GPS and Applanix POS-AV |
Technical Data Digital Camera
Picture types |
|
Color or Color-Infrared |
CCD-Array Size |
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4080 (along flight) x 5440 (cross flight) pixel |
Pixel Size |
|
0.009 mm |
Lens |
|
f=47 mm, 42° FOV (along flight), 55° FOV (cross flight) |
Typical Ground Sampling Distance |
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at 1000 m flying height above ground: 20 cm |
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