TECHNICAL INFO

I. DIMAC CAMERA UNIT

1. Camera module assembly

Each camera module is a completely INDEPENDANT assembly.
Each camera module takes individual images.
DIMAC’s modular design fits your real needs, allowing to combine 1, 2, 3 or 4 camera modules together (multi-spectral or Infra Red) and producing 1, 2, 3 or 4 juxtaposed images. This, in turn, will enable small, medium or large scale mapping, multi-spectral or Infra Red.

The camera module assembly consists of the following components:

1.1. KODAK Matrix CCD RGB Colour Management
Each camera module is fitted with a Kodak True Colour Matrix CCD Sensor (5440 by 4080 effective pixels). This means that EACH Pixel has it’s OWN colour.
Specifications: See Technical Specifications

1.2. TRUE Forward Motion Compensation (FMC)
Each camera module is fitted with an individual Piezo controlled FMC(patent*) .
FMC operates at each image acquisition, automatically during the flight.
FMC compensates the aircraft movement due to the forward speed and the mission flight altitude
FMC operates according to the chosen pixel size, the aircraft speed and corresponding shutter speed.
FMC enables to make maximum use of the lens properties thanks to the shutter speed (1/125 sec to 1/500 sec) and the diaphragm settings.

1.3. Digital lens assembly.
Each camera module is delivered with a dedicated very high quality digital lens (Schneider, Rodenstock).
Our CCD assembly remains in the CENTRE of the optical circle.IMPORTANT: The MTF curve is constant in the central zone of the image circle. This allows homogenous colour & contrast for the digital images.

Thanks to the modular design technology, the DIMAC Camera can be optimised for the following configurations:

For photogrammetric application:
Recommended digital lens specifications: Focal Length 80 mm – Optical Power = 4.
These settings get excellent light modulation properties (MTF) .

Illustration: MTF Curve with the following settings:
Diaphragm setting of the shutter (k) = 8.0
Lens calibrated for infinity.
Resolution: 60 Linepairs per mm.
The arrow shows the MTF curve to consider.The arrow indicates the limit of ONLY 75% of utilisation of the optical circle.

For orthophoto application:
Recommended digital lens specifications: Focal Length 120 mm – Optical Power = 5.6
These settings offers the best Light Modulation Properties (MTF), for optimal contrast.

IMPORTANT: For a given lens, the optimal contrast requires a high MTF curve (i.e. diaphragm =11). Such curve requires a longer exposure time which can be obtained thanks to the movement compensation of our FMC system.

Illustration: MTF Curve with the following settings:
Diaphragm setting of the shutter (k) = 11.0
Lens calibrated for infinity.
Resolution: 60 Linepairs per mm.
The arrow shows the MTF curve to consider.
The arrow indicates the limit of ONLY 70% of utilisation of the optical circle.

1.4. Electronic Shutter System by Rollei
Each CM is equipped with a dedicated Electronic Shutter fitted to the digital lens. The shutter trigger is performed through a Proprietary Computer Controlled Trigger Signal. The Master Computer (MC) controls and synchronizes each individual electronic shutter.

1.5. Digital Filters by Jos Schneider
Each CM is available with either Multi-spectral (BG) or Infra-Red filters to get the best digital image definition

IMPORTANT: Each CM is factory calibrated for correct operation between CCD and Digital Lens System. Each module is sold as a customer PREDEFINED configuration (CCD Orientation/Type of Lens) which CANNOT be modified in the field.

2. Camera Cynlindrical Frame (CCF)

The Camera Cylindrical Frame (CCF) consists of a steel base plate and a cylindrical envelope (diameter 40 cm).
The CCF can contain up to 4 Camera Modules (CM) and the Inertial Measurement Unit (IMU -Optional).
The CM and IMU are assembled in a predetermined geometric position, essential for the aerial triangulation.
The lower part of the CCF is protected by an In-flight removable steel protection plate.
The CCF provides an environmentally controlled housing to maintain the equipments at a constant temperature of 10°C.

2.1. Base plate mounted on anti-vibration support
The steel base plate is mounted on a vibration absorbing support to alleviate vibrations transmitted from the aircraft to the DIMAC Camera System.
2.2. The base plate is delivered with 4 Holes
The base place can accept up to 4 Camera Modules (CM-1, CM-2, CM-3, CM-4 or CM-IR).

2.3. The CCF with patented Slope Interfaces Plates
The CCF is provided with a interchangeable Slope Interface Plates – SIP (patent*)
Each DIMAC Camera is delivered with the 6 Slope Interface Plates: 2 horizontal plate (0°) and 4 inclinated plates (2x 6°, 2×8°).
The SIP are used according to the transversal overlap required between the images.

2.4. Base plate provides a rigid support for the IMU
The base plate is fitted with a rigid steel attachment for the Inertial Measurement Unit (Optional).
The IMU delivers x, y, z and angle information, essential for digital image processing.

2.5. The CCF with a protection plate
The CCF is equipped with an In-flight removable protection plate to prevent humidity and dirt projections onto the lenses during take off and landing.
2.6. The CCF placed on a Gyro Stabilized Platform
The CCF must be placed on a Gyro Stabilized Platform to compensate for aircraft movement during image acquisition (Optional).

2.7. Inertial Measurement Unit (IMU)
The OPTIONAL Inertial Measurement Unit (IMU) is used to measure all the horizontal, vertical and angular positions of the CCF.
These measurements are made for EACH image, triggered by the CCNS4 Flight Management System. We HIGHLY recommend using an IMU (optional) since all digital images require triangulation data for high accuracy.

II. DIMAC ELECTRONIC RACK

1. Camera Management Computer (CMC)

The Camera Management Computer is at the heart of the DIMAC Camera, where the Image acquisition is centralized.
This master computer controls & synchronizes the FMC system, the electronic shutter and up to 4 Module Computers (MC, see below).

The CMC and MC’s are mounted in dedicated aircraft rack which make their installation and removal from the aircraft very easy.

Specifications:


Operates on 28V DC Aircraft Power.

Receives flight plan data from CCNS4 Flight Management System.

The Operating System (OS) runs on a 2 GB Flash RAM.

The CMC individually controls up to 4 FMC Systems.

The FMC compensates according to desired pixel size and aircraft speed.

In-flight control of the image acquisition.

Before each flight mission, the CMC determines shutter speed and aperture setting.

The CMC controls the shutter and aperture settings during the image acquisition time.

All the camera settings are stored in the CMC over the whole mission.

CMC controls and synchronises the FMC (Piezzo system), the different CM and the MC.

2. Module Computer – Up to 4 Modules (MC)

A dedicated Module Computer (MC) collects the image data from it’s corresponding Camera Module CM (see below).
Each MC handles the image data acquisition for its dedicated camera module.
Specifications :

The image data is stored on 2 high quality 120 MB removable hard disk drives (HDD).

An optional Operating System on 2 GB Flash RAM is available.

The mirroring technology ensures permanent back up of the stored data (i.e. 1 HDD/ Back Up).

The 120MB HDD storage offers a capacity of up to 2500 digital images (digitally unprocessed).

IMPORTANT: Thanks to the interchangeability of the DIMAC Camera system, a spare CM and MC, can be easily the exchange in the field.

III. DIGITAL IMAGING PROCESS WORKFLOW

Follow this workflow chart to purchase the DIMAC configuration corresponding to your real needs.
1. What are the image specifications?

Determine YOUR exact requirements:
• What is the accuracy / scale of your project?
• According to the accuracy you determine Ground Pixel Size
• Is it a Photogrammetric or an Orthophoto Contract ?
• Is a DTM (Digital Terrain Module) required?
2. Generate your mission planning
The mission planning is based on the ground pixel size & the ‘z’ accuracy requirements. Mission planning is set-up using IGI CCNS 4 Flight Guidance System.

3. Configure the DIMAC camera

DIMAC’s modular design fits your real needs, allowing to combine 1,2,3 or 4 camera modules together (multi-spectral or Infra Red) and producing 1,2,3 or 4 juxtaposed images. This, in turn, will enable small, medium or large scale mapping, multi-spectral or Infra Red.

We illustrate here below the different module configurations inside the DIMAC Camera Cylindrical Frame
Note that the Matrix CCD Sensor is 5440 x 4080 Pixels

A. CONFIGURATION “1/Par” (Single Camera Module – Parallel to the flight direction)
Basic photogrammetric configuration
Orientation
5440 pixels parallel to the flight direction

Indicated in
Precision photogrammetric work in elevation (z) Small areas or following linear targets (pipes or power lines) Small orthophoto missions
Transversal footprint
4.080 pixels
Optimal altitude accuracy (z)
Base/Height Ratio (B/H) = 0.24
Module inclination
Horizontal – Slope interface = 0°
Focal length of digital lens (recommended)
80mm
Ground pixel size determine the flight altitude
See table “Pixel Size – 1/Par”
B. CONFIGURATION “1/Perp” (Single Camera Module – Perpendicular to the flight direction)
Basic orthophoto configuration
Orientation
5440 pixels perpendicular to the flight direction
Gives a wider image foot print than configuration “1/Par”

Indicated in
Orthophoto missions Larger urban area mapping than configuration “1Par”
Transversal footprint
5.440 pixels
Optimal altitude accuracy (x, y)
Base/Height Ratio (B/H) = 0.12
Module inclination
Horizontal – Slope interface = 0°
Focal length of digital lens (recommended)
120mm
Ground pixel size determine the flight altitude
See table “Pixel Size – 1/Perp”
C. CONFIGURATION “2/Par” (Dual Camera Module – Parallel to the flight direction)
Precision photogrammetric configuration
Orientation
5440 pixels parallel to the flight direction

Indicated in
Precision photogrammetric work in elevation (z) Small areas or following linear targets (pipes or power lines) Orthophoto missions
Transversal footprint
6.500 pixels
Optimal altitude accuracy (z)
Base/Height Ratio (B/H) = 0.24
Optical module inclination
Slope interface = 8°
Focal length of digital lens (recommended)
80mm
Footprint overlap
CM-1+CM-2 = 20-25% *
Ground pixel size determine the flight altitude
See table “Pixel Size – 2/Par”

*CM = Camera Module
D. CONFIGURATION “2/Perp” (Dual Camera Module – Perpendicular to the flight direction)
Precision orthophoto configuration
Orientation
5440 pixels perpendicular to the flight direction
Gives a wider image foot print than configuration “2/Par”

Indicated in
Orthophoto missions only
Transversal footprint
8.500 pixels
Optimal altitude accuracy (x, y)
Base/Height Ratio (B/H) = 0.12
Optical module inclination
Slope interface = 6°
Focal length of digital lens (recommended)
120mm
Footprint overlap
CM-1+CM-2 = 20-25% *
Ground pixel size determine the flight altitude
See table “Pixel Size – 2/Perp”

*CM = Camera Module

E. CONFIGURATION “3/Par” (Triple Camera Module – Parallel to the flight direction)
Orthophoto and accurate DTM configuration
Orientation
5440 pixels parallel to the flight direction
This orientation gives a very wide image foot print

Indicated in
rate DTM
Orthophoto missions
Transversal footprint
10.000 pixels
Optimal altitude accuracy (z)
Base/Height Ratio (B/H) = 0.16
Optimal module inclination
Slope interface CM-1+CM-2 = 10°, CM-3 = 0° *
Focal length of digital lens (recommended)
120 mm
Footprint overlap
CM-1, CM-2+CM-3 = 25 % *
Ground pixel size determine the flight altitude
See table “Pixel Size – 3/Par”

*CM = Camera Module

F. CONFIGURATION “2+2/Par” (Quadruple Camera Module – Parallel to the flight direction)
High precision photogrammetric work at low level and/or high speed flight configuration – Alternating triggering
Combination
Alternative triggering between CM-1+CM-2 and CM-3+CM-4
Orientation
5440 pixels parallel to the flight direction

Indicated in
Pure photogrammetric (high accuracy) for low level or High speed flight
Transversal footprint
6.500 pixels
Optimal altitude accuracy (z)
Base/Height Ratio (B/H) = 0.24
Optimal module inclination
Slope interface for all CM = 8° *
Focal length of digital lens (recommended)
80 mm
Alternating triggering
Alternate CM-1+CM-2 and CM-3+CM-4 *
Footprint overlap
All CM = 20 – 25% *
Ground pixel size determine the flight altitude
See table “Pixel Size – 2/Par”

*CM = Camera Module

G. CONFIGURATION “2/Par+2/Perp” (Quadruple Camera Module – multiple orientation)
Combined Precision Photogrammetric & Orthophoto/DTM Configuration
Combination Multiple missions so NO camera module change is required
CM-1+CM-2 for photogrametric missions
CM-3+CM-4 for orthophotomissions
Camera Modules 1&2
Orientation
CM-1+CM-2: 5440 pixels parallel to the flight direction

Indicated in
Precision photogrammetric work in elevation (z)
Transversal footprint
6.500 pixels
Optimal altitude accuracy (z)
Base/Height Ratio (B/H) = 0.24
Optimal module inclination
Slope interface CM-1+CM-2 = 8° *
Focal length of digital lens (recommended)
CM-1+CM-2 = 80 mm *
Footprint overlap
CM-1+CM-2 = 20-25% *
Ground pixel size determine the flight altitude
See table “Pixel Size – 2/Par”

*CM = Camera Module

Camera Modules 3&4
Orientation
CM-3+CM-4: 5440 pixels perpendicular to the flight direction Gives a wide image foot print

Indicated in
Orthophoto Missions
Transversal footprint
8.500 pixels
Optimal altitude accuracy (x, y)
Base/Height Ratio (B/H) = 0.12
Optimal module inclination
Slope interface CM-C & CM-D = 6° *
Focal length of digital lens (recommended)
CM-3+CM-4 = 120 mm *
Footprint overlap
CM-3+CM-4 = 20-25% *
Ground pixel size determine the flight altitude
See table “Pixel Size – 2/Perp”

*CM = Camera Module

H. CONFIGURATION ‘1/Par + 1/Par/IR’ (IR & Single Camera Module – Parallel to the flight direction)
Combined precision photogrammetric & Infra Red configuration
Combination
Second camera module fitted with Infra Red filter for simultaneous Infra Red and multi spectral
Orientation
5440 pixels parallel to the flight direction

Indicated in
Precision photogrammetric work in elevation (z) Small mission areas, or following linear targets (pipe or power lines)
Orthophoto missions
Transversal footprint
CM-1 & CM-IR = 4.080 pixels *
Optimal altitude accuracy (z)
Base/Height Ratio (B/H) = 0.24
Optimal module inclination
Horizontal – Slope interface = 0°
Focal length of digital lens (recommended)
CM-1 & CM-IR = 80mm *
Footprint overlap
CM-1 & CM-IR = 100% *
Ground pixel size determine the flight altitude
See table “Pixel Size – 1/Par”

*CM = Camera Module

I. CONFIGURATION ‘2/Par + 1/Perp/IR’ (IR & Dual Camera Module – Parallel to the flight direction)
Combined precision orthophoto & Infra Red configuration
Combination
Third camera module fitted with Infra Red filter for simultaneous Infra Red and multi spectral
Orientation
CM-1+CM-2: 5440 pixels parallel to the flight direction
CM-IR : 5440 pixels perpendicular to the flight direction

Indicated in
Orthophoto AND accurate DTM
Combined orthophoto missions
Transversal footprint
CM-1+CM-2 = 6.500 pixels
CM-IR = 5.400 pixels
Optimal altitude accuracy (z)
Base/Height Ratio (B/H) = 0.24
Optimal module inclination
Slope interface CM-A & CM-B = 8°
CM-IR = 0° *
Focal length of digital lens (recommended)
CM-1 & CH-3=120mm *
CM-IR = 60mm (wide)
Footprint overlap
CM-1+CM-2 = 20-25%
CM-IR = 100% *
Ground pixel size determine the flight altitude
See table “Pixel Size – 2/Par” for CM-1+CM-2
See table “Pixel Size – 1/Perp” for CM-IR

*CM = Camera Module

J. CONFIGURATION “3/Par + 1/PerpIR” (IR & Triple Camera Module – Parallel to the flight direction)
Combined precision orthophoto, accurate DTM & Infra Red configuration
Combination
Fourth camera module fitted with Infra Red filter for simultaneous Infra Red and multi spectral
Orientation
CM-1+CM-2 & CM-3: 5440 pixels parallel to the flight direction
CM-IR: 5440 pixels perpendicular to the flight direction
Orientation gives very wide image foot print, excellent for orthophoto missions

Indicated in
Orthophoto AND accurate DTM
Combined orthophoto missions
Transversal footprint
CM-1+CM-2+CM-3 = 10.000 pixels
CM-IR = 5.400 pixels
Optimal altitude accuracy (z)
Base/Height Ratio (B/H) = 0.16
Optimal module inclination
Slope interface CM-1+CM-2 = 10°
CM-3 & CM-IR = 0° *
Focal length of digital lens (recommended)
CM-1+CM-2+CM-3 = 120 mm*
CM-IR = 60mm (wide)
Footprint overlap
CM-1+CM-2+CM-3 = 25%
CM-IR = 100%*
Ground pixel size determine the flight altitude
See table “Pixel Size – 3/Par” for CM-1+CM-2+CM-3
See table “Pixel Size – 1/Perp” for CM-IR

*CM = Camera Module

IV. TECHNICAL SPECIFICATIONS

1. DIMAC CAMERA UNIT

1.1. DIMAC Camera Module

1.1.1. Sensor

Technology Kodak full frame CCD sensor
Pixel size 9 x 9 micron
Pixel capability 5440 x 4080 effective pixel RGB
Physical format 48.9 x 36.7 mm
Capture rate 2.1 sec per image
Temperature range Maintain > 0°c inside module

1.1.2. Digital image

Color depth 16 bit per color
24 bit RGB : 68 Mbytes
48 bit RGB : 130 Mbytes
Basic sensitivity ISO : 50. 100. 200. 400

1.1.3. Optical system

High resolution lens Rodenstock APO-Sironar digital HR infinity.
Schneider APO-Digitar calibrated on Infinity.
Exchangeable lenses 60, 80, 100, 120, 150 mm
Exchangeable shutter Rollei electronic ( 1/500 to 1/125 )
Shutter control Integrated electronic assembly

1.1.4. F.M.C. (Forward Motion Compensation)

F.M.C. device Piezo actuated by F.M.C. control board
Travel : 60 micron
True F.M.C. True motion of CCD sensor during image aquisition

1.1.5. Ground pixel size

Ground pixel size from 5 cm to 1 m

1.2. DIMAC Camera Cylindrical Frame

1.2.1. Configuration

Diameter 40 cm
Number of modules Contains up to 4 modules
Modules slop By slope interface: 0°, 5°, 6°, 7°, 8°, 10° following focale distance
weight 35 kg with 4 modules

1.2.2. Mount (option)

Operating system interfaced with Gyro stabilizer
Drift control and correction with CCNS 4

1.2.3. Flight management system (option)

Mission planning software Images triggered by CCNS4

1.2.4. Inertial measurement unit I.M.U. (option)

Equipment Aerocontrol AC by IGI
Applanix POS AV 410/510

2. DIMAC ELECTRONIC RACK

2.1. Camera Management Computer (C.M.C.)

Centralisation of control Receives predefined mission data from CCNS4
Synchronisation of image aquisition
Synchronisation of F.M.C.
Synchronisation of image
Operating system Windows 2000 Pro
System storage Fast Flash Disk
Shutter control and setting Proprietory DIMAC software
Voltage Operate on 28 VDC (19 =>32V DC)
In flight image control Enabled via Capture One software

2.2. Module Computer (M.C.)

Redondancy RAID System Mirroring Technology
Operating system Windows 2000 Pro
Data storage + transfer Removable Dual 120GB Hard Disk Drive (HDD)
Image aquisition capacity in flight Capture One software
Images per camera module > 2 000 images / single unit/dual HDD

2.3. Forward Motion Compensation (F.M.C.) control board

Interfaced with CCNS4 Real-time operation (a/c speed,release events)
Interfaced with global camera management computer Remote set-up (pixel size, shutter speed, …)
Control capacity Independant control of each individual CM

2.4. KVM Module computer selection cable

Switch keyboard, display & mouse on the selected computer

2.5. Keyboard and touchpad

Keyboard drawer (for data entry and control)

2.6. Network module

Gigabit Ethernet network (5 ports max.)

2.7. 17” LCD screen

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