Rainer Sandau
DESIGN PRINCIPLES OF THE LH SYSTEMS ADS40 AIRBORNE DIGITAL SENSOR
Rainer SANDAU', Bernhard BRAUNECKER‘, Hans DRIESCHER”, Andreas ECKARDT*,
Stefan HILBERT", Joe HUTTON", Werner KIRCHHOFER', Erik LITHOPOULOS*,
Ralf REULKE,, Stefan WICKI'
‘LH Systems GmbH, Switzerland
sandau Q Ih-systems.com, kirchhofer Ih-systems.com, wicki ? Ih-systems.com
“Leica Geosystems AG, Switzerland
bernhard.braunecker @leica-geosystems.com
?Deutsches Zentrum für Luft- und Raumfahrt (DLR), Germany
Institute of Space Sensor Technology and Planetary Exploration
hans.driescher 9 dlr.de, andreas.eckardt 9 dlr.de, ralf.reulke 9 dlr.de
^ Applanix Corporation, Canada
jhutton @applanix.com, elithopoulos @applanix.com
Working Group 1/3
KEY WORDS: Camera, CCD, Photogrammetry, Remote Sensing, Design, Sensors
ABSTRACT
Digital imagery from satellites or multispectral and hyperspectral scanners is well accepted. Tremendous challenges are
inherent in the development of a digital sensor to acquire imagery suitable for both high precision photogrammetric
mapping and image processing for interpretative purposes. The performance of the film aerial camera is almost
impossible to reach with current digital technology. Joint development work by LH Systems and Deutsches Zentrum fiir
Luft- und Raumfahrt (German Aerospace Centre, DLR) has led to considerable success using forward-, nadir- and
backward-looking linear arrays on the focal plane to provide panchromatic imagery and geometric information,
supplemented by further arrays for multispectral data. This has culminated in the ADS40 product.
In the paper, all essential components of the ADS40 are addressed: optics, filters, CCD type and configuration, front-
end electronics, computer, flight management and sensor control software, mass memory, and attitude and position
measurement system. The imagery from the new sensor will fulfil many market requirements between the highest
resolution film imagery (<0.15 m) and high-resolution space imagery (1-10 m). The sensor’s unique blend of
multispectral information with high quality geometric information will give rise to numerous new applications.
1 INTRODUCTION
LH Systems announced at the end of 1998 after about one year of development that an engineering model of their
forthcoming airborne digital sensor had been flown successfully. The development, jointly undertaken with Deutsches
Zentrum fiir Luft- und Raumfahrt (German Aerospace Centre, DLR) in Berlin has been completed now: the ADS40, a
genuine alternative to the familiar aerial film camera, is available. Except for producing stereoscopes, LH Systems and
its predecessor Leica were never active in image interpretation. Yet this new sensor has multispectral lines on the focal
plane: it can generate precise, geometric information about the surface of the earth, but also produces data amenable to
remote sensing techniques. It will further soften the demarcation between photogrammetry and remote sensing and
accelerate the decline of the photo laboratory, as digital image data can be transferred from the aircraft directly to the
workstation.
The debate about airborne versus spaceborne imagery continues. The highest resolution applications, with ground pixel
sizes in the one centimetre to one decimetre level, are likely to remain the province of the film camera. Yet there is a
huge, pent up demand for top quality, multispectral information in the gap between this and the one metre and coarser
resolutions offered by the satellite operators. Both spaceborne and airborne sensors have their advantages and data
fusion will flourish as users select the sensors most likely to provide their information in each case and rely on software
to use all the data together. The two types of data will be complementary rather than competitive.
258 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B1. Amsterdam 2000.
Th
vel
fro
the
bet
CC
Th:
phe
its
len
are
the
len:
tele
for
the
