configuration item | specification
TLS Camera | CCD Elements | pixels/line i 14,400
i. 1 1 671 | pixel pitch | 2S Spm —
Number of Sensors | 10 (3 directions — with RGB - and NIR)
| Intensity dynamic range | 9 bits or more
| Lens focal length 60 mm
| Stereo angle 17 ..23 ,40' etc
| Number of capturing lines 125, 250, and 500 lines/sec
Stabilizer
{ Angle resolution in attitude | 0.00128
| spatial stability Erb ! 0.00029
| Maximum angle velocity 30° /sec ; zt
| Data output (acceleration/attitude) 500 Hz
GPS Receiver | 2f kinematics | planimetric accuracy |
2cm + 2 ppm
| (post processes) | height accuracy 3cm + 2 ppm
| Data output | 5Hz
Recorder | HDD recording | recording speed | 150 MB/sec or more
| + — ^ - ee t — à — —
| | recording capacity | 320 GB
Table 1. SI-250 system specifications
As a result, STARIMAGER produces seamless high-resolution
images (5 — 10 cm footprint on the ground) with three viewing
directions (forward, nadir and backward) There are two
configurations for image acquisition. The first ensures the
stereo imaging capability, in which the three CCD arrays of the
red channels are read out. The second configuration uses the
RGB CCD arrays (see Figure 6 for the spectral channels) to
deliver color imagery.
GPS Anntena
INS*Camera
Stabilizer Center
^ GPSIIMU Vector
Camera Center E
7 INS/Camera Vector
Figure 4. Sensors for STARIMAGER
Figure 5. Electronic units in the helicopter cabin
After the collection of the GPS/INS raw data, the kinematic
position and attitude data are calculated. This results in drift
values for the IMU observations, which currently have to be
recovered, together with possible other systematic errors, by
triangulation.
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B1. Istanbul 2004
Image Sensor (CCD) - Responsivity
10
|
[6 +
350 400 450 500 550 500 650 700 750
800 (nnm) 850
Figure 6. Spectral channels for SI-250
2.3 Camera calibration
STARLABO performs both laboratory calibration and field
calibration before utilizing the TLS camera for 3D.
measurements to ensure a certain level of accuracy. The
laboratory calibration (see Figure 7) includes geometric tests
(CCD pixel position, distortion, MTF, etc.) and radiometric
tests (sensitivity, PRNU, linearity, S/N, etc). The field
calibration uses self-calibration to determine the camera
distortion data (Chen et al., 2003).
Figure 7. Optical system for laboratory calibration
The TLS camera tester (see Figure 8) provides day-to-day
maintenance services including quick checking of a variety of
sensing capabilities including sensitivity, MTF, S/N, etc. before
the actual operations.
Figure 8. TLS Camera Tester
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