LAST GENERATION UAV-BASED MULTI- SPECTRAL CAMERA FOR AGRICULTURAL DATA ACQUISITION

Transcription

1 LAST GENERATION UAV-BASED MULTI- SPECTRAL CAMERA FOR AGRICULTURAL DATA ACQUISITION FABIO REMONDINO, Erica Nocerino, Fabio Menna Fondazione Bruno Kessler Trento, Italy Marco Dubbini, Michaela De Giglio Univ. Bologna Italy Mario Gattelli SAL Engeenering Ravenna, Italy Daniele Covi Eoptis Trento, Italy

2 Multispectral cameras Agriculture Precision farming Vegetative index mapping Water supply planning Optimize pesticide use Fertilization tuning Yield estimation Health condition monitoring Early detection of disease Environmental monitoring and survey surface geology survey spill of pollutant or hazardous substances Biomass mapping Industry remote chemical imaging large industrial plant monitoring Parrot Sequoia MicaSense RedEdge TetraCam Maia

3 MAIA multispectral camera MAIA: The most advanced multispectral imaging camera for drones (UAVs), aircraft and land-vehicles available today Photogrammetry-ready images in 8+3 VIS/NIR bands 2 versions: MAIA/S1 (bands very close to WorldView2) and MAIA/S2 (bands very close to Sentinel2A) 420 gr, 128 GB internal disc, 9x 1.2 Mpix sensor global shutter

4 MAIA features 8 bands (sensors) cover the full VIS-NIR range + 1 RGB Plug-and-play for immediate use Configuration and live image view over WiFi Rich set of interfaces and full access to any camera setting for precise control 9x 1.2 Mpix sensor Global Shutter 12 bits Factory lens geometric calibration Irradiance sensor with matched bands for reflectance measurements (patent application) Bundled scientific-grade image processing software

5 Key technical specification 9 sensors: 1 RGB color + 8 bands in the VIS-NIR range ( nm). Bands are very close to WorldView2 and Sentinel2A satellites. 1.2Mpix CMOS sensor (1280 x 960) Global shutter, bbest-in-class sensitivity bits per pixel data depth Simultaneous shot of all sensors up to 6fps at 8 bit (3fps at bit) Certified geometric calibration of each sensor/lens. 3cm ground sampling distance (GSD) 45x34m 2 field of view (FOV) at 75m flight altitude above ground. Full automatic or manual exposure mode, each sensor individually tunable. Small size (99x128x46)mm 3 Low weight (420g) MAIA features Features and benefits An extensive band set covering the full spectrum including 2 unique bands for pollution detection on water and soil + water supply planning. Sharp and deeply detailed images with no motion artifacts even with fast UAV speed. Data ready for precise data analysis and photogrammetric processing. Extremely detailed images with large area coverage for cost-effective data collection. Total control of the exposure parameters for high-quality images. Fits fixed-wings and multi-rotor UAVs, with limited impact on other payload.

6 MAIA features Key technical specification Trigger input and strobe output sync signals. 250/500 GB internal storage capability (on demand) - 128GB standard version Built-in WiFi and GigE interface with web-based interface for configuration, live image view and access to stored data Input for external GNSS serial port with NMEA strings detection On-board 6-axis inertial unit with accelerometer and gyroscope (IMU) Remote controller input with event detection Features and benefits Precise timing control of the image shot and sync of external devices. ~ 3 hours of acquisition at 8bits, 1fps (128GB free space) Wireless on-field access via smartphone, tablet or PC for image stream and configuration. Fast cable data download at home. Accurate positioning of any image, for example with RTK GNSS. Effective image stabilization and seamless integration into body. Eulerian angles writings in log file for each image. Easy control of key parameters during flight.

7 MAIA platforms

8 MAIA/S1 spectral bands Bandwidth (nm) Approx. color Violet (Coastal) Blue Green Orange Red Red Edge NIR NIR2 9 (VIS) (RGB) The 8 bands of MAIA span the full VIS/NIR spectrum and are very close to WorldView2 satellite

9 MAIA/S1 spectral bands Wavelength (nm) Coastal areas and marine environment Unaffected by atmospheric scattering Distinction between soil to vegetation Unaffected by atmospheric scattering Reflectance peak for healty vegetation, plant classification Weak influence from atmosphere additional info on biomass Moisture content of biomass Strongly depending on chlorophyll content Classification of vegetation, health status Absorbed by chlorophyll Detection of soil and geological features Plant classification, yellowing of foliage

10 MAIA/S2 spectral bands Wevlength (nm) Bandwidth (nm) Central Wavelength (nm) The 8 bands are the same to Sentinel2A satellite (VIS/NIR)

11 MAIA Irradiance sensor (ILS) Radiometric radial correction applied to correct the border effects of the image (usually darker pixels) that can arise due to the curvature of the lens Radiometric adjustment applied to correct the DN (Digital Number) errors by considering the amount of irradiant light at the time of the image acquisition Irradiant Light Sensor (ILS): true reflectance measurement under any light condition for each bands independently Integrated cm-level GNSS positioning with Real Time Kinematics (L1 - RTK) Pixel-level geo-referenced and radiometric corrected images without ground targets (very time-consuming task) Radiometric adjustment mandatory when comparing data with multi-time acquisitions

12 MAIA Geometric calibration Calibration testfield with some 80 coded targets (35mm and 5 mm diameter) Image network with ca 40 camera positions at three different heights with roll diversity Brunson certified length bars for scale and length measurement errors (VDI/VDE 2634) Tungsten halogen source, emitting light in all the wavelength intervals acquired by the MAIA sensors, to guarantee the proper illumination during the image acquisition step

13 MAIA Processing software Powerful processing and unique features designed for users without background in photogrammetry

14 MAIA Processing software pipeline Multispectral aerial survey of the area of interest Image undistortion and co-registration 8+3 layers with several geometrical imperfections Radiometric correction DSM & geo-referenced orthophoto Computation of vegetation indexes Reflectance values of the target DN proportional to light hitting the target 8+3 pixel-to-pixel matching layers Analysis and actions MAIA UAV-BASED MULTI-SPECTRAL CAMERA F. Remondino et al. NDVI GNDVI SAVI

15 GRAZIE PER L ATTENZIONE Dubbini et al., 2016: Last generation instrument for agriculture multispectral data collection. Agricultural Engineering International: CIGR Journal Nocerino et al., 2017: Geometric calibration and radiometric correction of the MAIA multispectral camera. Int. Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences, in press. Proc. SPEC3D ISPRS Workshop MAIA website