MAIA - The multispectral camera

CMOS sensors settled in MAIA has 1280x960 pixels and the dimension of each pixel is 3.75 μm x 3.75 μm. Sensors present excellent characteristics in terms of sensitivity. Each sensor is global shutter and shoot simultaneously: it follows that it is not necessary to stabilize acquisition with gimbal, which is indispensable with roling shutter sensors to avoid distorsions, crawling and blurring pixels in the images. The high quality and the radiometric validity of data obtained with MAIA are then guaranteed even during high speed flghts.

Each optics of every produced MAIA is calibrated in laboratory and for each camera the Calibration Certificate is available, with the following parameters:

• calibrated Focal Length;
• position of Principal Point;
• distortion lens parameters.

Calibration and certificate is carried out by 3DOM group - 3D Optical Metrology of FBK - Fondazione Bruno Kessler based in Trento (IT), in their laboratories.

The user can interact with the camera to configure operating parameters and to manage the images both through the GigaEthernet port and through integrated Wi-Fi. Many parameters can also be configured through the dedicated keypad using the On-Screen Display on the output port of the composite video. Thanks to a web panel, MAIA permits a fine regulation of all parameters concerning the acquisition activities, from exposure time of each sensor to shot frequency. Automatic configurations are available for standard operations.

MAIA can communicate and can be interconnected with various devices including:

• GNSS:GPS L1 or L1 / L2; GLONASS, Galileo, Beidou, for an accurate log of synchronized shutter positions (available in PPP, PPK, RTK);VIDEO TX for real-time transmission of images of the selected sensor, also remotely;
• RDX for remote control of the camera (frame rate, video source selection, wi-fi activation);
• GIMBAL for attitude and balance control (an integrated IMU with 3 accelerometers and 3 gyroscopes provides orientation parameters)

Images are stored in an internal hard disk (120 Gb SSD) that provides high speed and the possibility to save about 10,000 images in the maximum format allowed (12-bit raw).

MultiCam Stitcher Pro is the images pre-processing software integrated with MAIA, that allows the correction of geometrical distortion, radial distortion of the raw images, and allows to stitch the images of each single band on one multispectral image with the pixel-pixel convergence. It also allows you to calculate, for each image, NDVI, SAVI index and any type of customized band calculations nd combination of bands.

MultiCam Stitcher Pro allows the radiometric calibration of images in different ways:

• reference image on white target, of which you know the reflectance coefficients;
• empirical parameters based quantum efficiency of the sensor, bandwidth, transmittance of the filters and exposure times;
• through parameters data obtained by Incident light sensor – ILS that analyzes the radiance of the light source for each acquisition.

The multispectral images can be exported in formats recognized by multispectral analysis softwares (eg. ERDAS™, ENVI™, PCI Geomatics™, etc.) and photogrammetric processing softwares, in order to generate 3D models and orthophotos of single-band images or indexes.

MultiCam Stitcher Pro software is jointly developed by SAL Engineering Srl and 3DOM - 3D Optical Metrology - Fondazione Bruno Kessler (FBK), based in Trento (IT).

Mono-chromatic sensors plus the RGB Bayer Pattern are matched with bandpass filter-set based on the wavelenghts intervals as follows:

Mono-chromatic sensors are matched with bandpass filter-set based on the wavelenghts intervals as follows:

Please visit www.spectralcam.com to find out our solutions for multispectral survey.