MAIA ILS – Incident Light Sensor

 Overview

The Incident Light Sensor integrated with MAIA multispectral camera measures the level of the ambient light for each shot in each band during multispectral survey. It allows the correction for downwelling light changes during the flight, such as those caused by clouds covering, and calculate the true reflectance ratios for the correct index calculations.

Furthermore, the ILS features a 6-axis inertial unit for motion processing, an environmental sensor for pressure, temperature and humidity measurement and a GNSS receiver with an embedded antenna that provides timestamp and position information for accurate geotagging of each image acquired by MAIA.

The ILS connects directly to MAIA  multispectral camera and is powered and controlled by it, without any specific action required by the user for its operation, once properly mounted on board.

All parameters measured by ILS are automatically stored into the log file related to the image acquisition set, and are available for pre-processing with MultiCam Stitcher Pro, the MAIA images pre-processing software.

A high precision GNSS version with RTK is available, which allows a centimeter-level positioning accuracy. In this case, an additional ILS which acts as base station is necessary for proper operations.

 ILS       1 990 €  VAT excl.

ILS RTK       2 560 €  VAT excl.

RTK BASE       1 820 €  VAT excl.

 

Frame

  • Size: 70 mm x 70 mm x 40 mm (excluding connectors)
  • Weight: 160 g

Mechanical design of the ILS case (measurements are in millimeters) and description of screws.

 

 Power supply

  • Powered by the MAIA WV multispectral camera (recommended);
  • powered by a 4.5 – 9 VDC / 600 mA supply.

Description of leds, plugs and components of ILS case.

 

 Irradiance sensor

  • True cosine correction of incident light;
  • accurate irradiance measurement thanks to patented technology;
  • incident light level measured for each band of MAIA multispectral camera, with matched spectra depending on the filter-set installed;
  • two versions of ILS – Incident Light Sensor correlated to filter-set settled in MAIA: ILS WV and ILS S2

 

Band Start WL (nm) Stop WL (nm) CWL (nm) Colour
1 395 450 422.5 Coastal
2 455 520 487.5 Blue
3 525 575 550 Green
4 580 625 602.5 Orange
5 630 690 660 Red
6 705 745 725 Red Edge
7 750 820 785 NIR 1
8 825 950 887.5 NIR 2

Summary of optical bands detected by ILS WV related to MAIA WV multispectral camera.

Download ILS WV – Incident Light Sensor Datasheet

 

 

Band Start WL (nm) Stop WL (nm) CWL (nm) Colour
1 433 453 443 Violet
2 457.5 522.5 490 Blue
3 542.5 577.5 560 Green
4 650 680 665 Red
5 697.5 712.5 705 Red Edge 1
6 732.5 747.5 740 Red Edge 2
7 773 793 783 NIR 1
8 784.5 899.5 842 NIR 2
9 855 875 865 NIR 3

Summary of optical bands detected by ILS S2 related to MAIA S2 multispectral camera.

Download ILS S2 – Incident Light Sensor Datasheet

 

6-axis IMU (Invensense ICM-20689)

  • 3-axis gyro with +/- 250 deg/s full-scale-range and 0.1 deg/s resolution;
  • 3-axis accelerometer with +/-4 g full-scale-range, and pitch and roll angles with 0.1 g resolution.

 

 Environmental sensor (Bosch BME280)

  • 0-60 ºC temperature measurement range, ±1 ºC accuracy (*);
  • 800-1100 mbar pressure measurement range, +/-1 mbar accuracy;
  • 0-100% RH humidity measurement range, +/-5% RH accuracy.

(*) The thermometer measures the temperature inside the ILS case, which is, in general, higher than the ambient temperature due to several external factors, including the heating caused by the solar radiation and the dissipation feature of the mounting fixture.

 

 GNSS receiver

  • Standard precision receiver or high precision RTK for centimeter-level positioning accuracy;
  • concurrent reception of up to 3 GNSS (GPS, Galileo, GLONASS, BeiDou);
  • navigation sensitivity of -165 dBm;
  • better and faster positioning, supporting all satellite augmentation systems;
  • integrated passive antenna;
  • SMA connector supporting active or passive external antenna.

 

 Key features

  • Irradiance levels of light measured with bands matched with MAIA multispectral camera;
  • GNSS receiver with onboard antenna, supporting the use of an external active or passive antenna;
  • 6-axis IMU and pressure, temperature, humidity sensors;
  • seamless connection to the MAIA multispectral camera;
  • data of each measured parameter are included in the camera log file;
  • single-cable connection to MAIA multispectral camera for power supply and control;
  • 1s measurement rate of all parameters, synchronized with the image acquisition;
  • micro SD card for additional log files storage (8 GB bundled);
  • USB interface to access the SD from the host computer without removing the SD.

MAIA WV and MAIA S2 can be equipped with the Incident Light Sensor – ILS for the radiometric correction of each single shot in each single band, for the best multispectral data acquisition:

  • determine precisely the fertilization by identifying the symptoms of nutritional deficiencies;
  • optimize the contribution of pesticides through the early identification of biotic stress;
  • optimize irrigation of crops by identifying areas of potential water stress;
  • calculate agronomic indices, and set a monitoring plan in order to preview the yeld of crops;
  • monitor dumps, water bodies, terrains, mines, soils and forests with a correct radiometric information, to create an effective monitoring plan of interventions.

 

Rear frame of ILS onboard DJI S900 ready to take-off. ILS has an integrated cm-level GNSS positioning system for Real-Time Kinematic survey.
Front frame of ILS with leds and interfaces. After the survey, the log file of ILS is directly linkable with MAIA shots to conduct georeferentiation and radiometric correction.

Pixel-level geo-referenced and radiometric corrected images without ground targets for GCP or radiometric correction (very time-consuming task).

Possibility to conduct multi-temporal surveys on the same crop, to enhance differences in vegetation health status or in pollutant detection.

MAIA WV and MAIA S2, equipped with the Incident Light Sensor, give you the ability to get the correct data for the best knowledge of the crop, so you can make the right decisions at the right time.

 

 

 

 

 

 

The Incident Light Sensor is equipped with GPS system and is installed above the aircraft, so that it is not shaded by any object during the flight.

  • True reflectance measurement under any light condition for each bands, independently.
  • Integrated cm-level GNSS positioning with Real Time Kinematics (L1 – RTK).
  • Possibility to build wireless network of base stations for wide area coverage.

The ILS captures and continuously registers the incident and diffuse light at the time of each single shot, at the same multispectral bandwidth intervals of MAIA WV or MAIA S2.

Radiance data for each single shot in each single band is related to GPS positioning data and ambient conditions data (temperature, humidity, orientation, exposure, and sun position) at the time of acquisition, allowing correct correction of the multispectral data, which is so comparable with satellite data (WorldView-2 or Sentinel-2 data) or multitemporal surveys carried out with the same arrangements.