A photogrammetric digital camera is an instrument that allows, through an electronic image sensor (a set of CCD's), to obtain metric digital images directly.STEREOCARTO has the technical means to capture and process photogrammetric data.
In particular STEREOCARTO has these large-format digital cameras:
- Leica ADS40 SH52 Sensor
- DMC Intergraph
ADS40 SH52 Leica
- Linear sweep technology (pushbroom). 12 CCD linear sensors, 12.000 pixel each.
* 4 pancromatic CCD: 27 degrees forward view, 16 degrees backward
view, two nadiral views with an overlapping of 3,25 microns.
* 2 x 4 multispectral CCD (red, green, blue and near infrared), with both
a nadiral and 16 degree backward views.
- Spectral bands without overlap.
- Focal: 62,7 mm. f/4.
- Pixel size: 6,5 microns
- GSD of 10 cm at 950 m of height.
- FOV: 64 degrees
- Stereo angles: 14, 27 and 41 degrees.
- Without shutter.
- Precision greater than 10 cm with direct orientation by means of differential GPS/INS using reference stations, including Ground Control Points and aerotriangulation.
- Precision of about 1 m with direct GPS/INS orientation by means of precise ephemerides without Ground Control Points nor aerotriangulation.
DMC Z/I Intergraph
- 4 high-resolution 7k x 4k PAN camera heads
- 4 multispectral 3k x 2k camera heads
- Camera electronic unit
- 3 mission data recorders each with 280 Gb disk space for 840 Gb of total in Flight Data Storage (FDS).
- Airborne Sensor Management System (ASMS), including core software, sensor control module and video camera.
- Ground-based Post Processing System (PPS).
- Configuration: 14k x 8k High Resolution Panchromatic and Multispectral
- Field of view: 69,3º cross track x 42º along track
- Panchromatic resolution: 7,680 x 13,824 pixels (final output image)
- Lens system: 4: x f = 120mm/1:4.0
- Multispectral number of channels : 4 RGB and Near-IR
- Raw MS camera resolution: 3K x 2K pixel
- Composited image resolution: 7,680 x 13,824 pixels (final output image)
- Lens system: 4 x f = 25mm/1:4.0
- Shutter and f-stop: Continuously variable 1/50 - 1/300 sec f/4-f/22
- On-board storage capacity (Mission Data Recorders): 840 GB (>2,000 images)
- Maximum frame rate: 2 sec / image
- Radiometric resolution: 12 bit (all cameras)
- Camera weight < 80 kg
- MDR (total) weight: 115 kg
- 5 spectral channels measuring simultaneously: pancromatic, red (λ = [590 – 675]nm), green (λ = [500 – 650]nm), blue (λ = [400 – 580]nm) and near infrared (λ = [675 – 850]nm).
- TDI (Time Delay Integrated) electronic FMC compensation.
- High-resolution digital images
- On-ground pixel width from 4 cm
- Panchromatic, color and near infrared images
- Images direct orientation
- Panchromatic, RGB, and 3 and 4 channels near infrared TIFF images.
- 8 or 12 bit images.
- With and without compression images.
- Tiled images.
APPLICATION OF DIGITAL CAMERAS
- Photogrammetric restitution for obtaining digital cartography.
- Digital photogrammetry: Orthophotos and True-Orthophotos
- Metric information files
- Environmental studies by using images representing the 4 channels during classification.
- Digital cameras are usually combined with LiDAR technology obtaining further products.
In general, digital cameras are good in tasks related with photogrammetry, cartography and photo-interpretation. In particular, it is the best technology for massive digital cartographic production with short-time schedules and high-performance requirements. Colour and infrared images are of high interest in environmental, agricultural and forestry studies.