Thermal and Spectral Imaging

In addition to conventional aerial photography, Hansa Luftbild offers imaging within various spectral ranges and thermal radiation images in conjunction with differing digital line scanners. The values of the captured data are recorded directly onto storage media, allowing processing of other sensor data to determine aircraft position and the establishing of geo-references.

The immediacy of such analysis is highly suitable during situations of danger and for environmental disturbances, allowing a swift determination of causes as well as rapid decision making concerning countermeasures.

The same technology is also highly suitable as a basis for the long term planning and management of land and forestry resources.

Geo-referenced or rectified results can be generated with varying colours or radiometric calibration according to customer requirements.

Examples of applications

Infrared Line Scanner

- the detection of the origin of leaks
- determine areas of heat loss
- research the distribution of heat within cities and towns
- trace warm currents in bodies of water
- identify coke fires e.g. in open-cast mines and waste disposal sites
- location of heat spots
- detection of environmental damage
- imaging of discharge into streams
- determine flooding and tidal flow patterns
- security surveillance of pipelines

Colour Line Scanner

- production of vegetation indexes
- ascertain land use
- classification of ground cover
- commercial forestry and environmental studies
- planning and surveillance for resource management

Digital Line Scanner

The sensors are mounted over a floor opening in the aircraft. Reflected and emitted signals from the ground cover are received and recorded, in lines, at right angles to the flight path, by a CCD sensor or through a rotating mirror which is controlled by a sensor.

Various bands of the spectrum can be captured by the Colour Line Scanner (CLS) through its four channels (red, green, blue and near infrared) three of which can be combined simultaneously. Ground resolution is 0.5 m and the number of pixels per line is 2048.

Thermal heat radiated by the earth at 8 to 12 µm is captured by the Infrared Line Scanner (IRLS) with high precision. Within the applied spectral band transmission of thermal radiation from the earth’s surface through the atmosphere is sufficient that measurement of landforms can be taken at high altitudes. Average resolution is 1.5 m and temperature differences of 0.1 degree Kelvin at ground level are detectable.

During daylight the flight can also be recorded by video camera.

Both systems were put into operation with the co-operation of Optimare Sensorsysteme AG

Technical Parameters of the Line Scanners:

Infrared Line Scanner

line frequency: 50 Hz (512 pixels per line, one byte per pixel)
scan angle: to +/- 44º (to plumb line)
maximum resolution at ground level: 1.5 m
maximum thermal resolution 0.1º K (at Delta T = 25ºK)
Spectral range: 8-12 µm
cooling of the semi-conductor detectors: Stirling
temperature regulation of reference plate: Peltier

Color Line Scanner

Line frequency: 50 Hz (2048 pixels per line) or 120 Hz (1024 pixels per line)
Scan angle: to +/- 45º (to plumb line)
max. resolution at ground level: approximately 0.5m
sensor: CCD (every colour pixel contains 3 sensor elements, 7 µm x 21 µm )
Spectral range: 420 – 470 nm (blue), 500 – 570 nm (green), 580 – 680 nm (red), 720 – 830 nm (near infrared)