Workswell’s CWSI camera is the first device of its kind designed to map water stress across large areas in the field of precision agriculture. The aim of this method and device is to determine the value of water stress in the plant stand. For example, this information may be used to determine yield maps, optimize irrigation, or control water management remedies. Camera offers LWIR band sensor (640×512) and 10x optical zoom RGB camera with resolution full HD (1920 x 1080 px).
The crop water stress index (CWSI) was developed (in 1981) as a normalized index to quantify stress and overcome the effects of other environmental parameters affecting the relationship between stress and plant temperature.
Crop drought – actual and real value
In the dry season what we are usually interested in is the actual effects of drought on crops. These impacts are not only dependent on the condition of the so-called climatic drought, but also on the groundwater drought, the size of the plant root system, etc. Measuring the water stress of plants with CWSI camera will help you to determine the actual and real effects of drought on the crop.
A CWSI of 0 indicates no water stress, and a value of 1 represents maximum water stress. The cropwater stress that signals the need for irrigation is crop specific and should consider factors such as yield response to water stress, probable crop price, and water cost. Reginato and Howe (1985) found that cotton yield showed the first signs of decline when the CWSI average during the season was greater than 0.2. [1], [2]
Potential yield maps
Based on the value of water stress, an approximate potential yield map can be determined. Obviously, the more plants are hit by drought, the lower their yield. Worksell CWSI Analyzer software, that comes in bundle with CWSI camera, makes it possible to generate potential yield maps from a large number of images across many hectares in a very short time (Challenging calculations common, for example, for orthophotogramers are not needed).
With CWSI camera you can get actual values of crop water stress during the flight, or you can use the collected data to create an overview map. By comparing yields from different years depending on water stress, a potential yield map can be created according to the current water stress value.
CWSI Camera – main benefits
Although there are many uses, we can divide the main CWSI camera usage into these three applications:
✅ Water status monitoring – To monitor water stress, ie. the lack of water that the crop is exposed to during the growing season. And regardless of whether the crops are irrigated or not. Special colour map “Crop” and “CropStep” are avaible.
✅ Manage irrigation management – Irrigation system optimization both in terms of determining suitable locations for the location of soil sensors and in terms of structure optimization. Special colour map “Water” and “WaterStep” for that application are avaible.
✅ Phenotyping – Different plant varieties are susceptible to the amount of water available. The CWSI camera will help you determine how often the plants of a given species are in water stress, compared to plants of other species.
Software included – CWSI Analyzer
Workswell CWSI Analyzer is a desktop software used to processing of CWSI images. It allows setting of individual parameters necessary for correct calculation of CWSI, both tabular and additional measurement. The software includes predefined most common crops where table values are entered directly. The big advantage of the software is the ability to process hundreds of images at once (mass data processing).
The software is supplied free of charge to the CWSI camera.
Sources
[1] Jackson, R.D., S.B. Idso, R.J. Reginato, and P.J. Pinter Jr. 1981. Canopy temperature as a crop water stress indicator. Water Resources Research 17:1133
[2] Plant stress mesurement – en.wikipedia.org/wiki/Plant_stress_measurement
| CWSI Camera key features description | |
|---|---|
| CWSI onboard processing | Evaluation of Crop Water Stress Index onboard |
| Operating onboard system | CWSI OS for full real-time data streaming and evalution during the flight - operating system ensures the full access to all camera functions - easy camera control via S.Bus, CAN bus, MavLink, RJ-45 or Trigger |
| 10x Optical Antivibration zoom | Full HD 10x optical zoom camera with anti-vibration compensation |
| CWSI camera specification | |
| CWSI sensor resolution | 640 x 512 pixels |
| CWSI evaluation | Workswell patented CWSI camera technology based on crop water stress index (normalized to value from 0 to 1) brings information about the crop stress and crop water management on large areas. The information can then be used to determine yield maps, manage irrigation or implement water management related remedies. |
| FPA active sensor size | 1.088 x 0.8705 cm |
| Type of sensor | LWIR band sensor |
| CWSI evaluation range | 0 – 1 (1 means very stressed) |
| Temperature sensitivity | 0.03 °C (30 mK) |
| CWSI calibration | Yes, calibrated for different ambient temperatures |
| Field of view of the lens | 45° |
| CWSI Colour-map | 4 colour maps for CWSI and Water management evaluation |
| CWSI range settings | Automatic, manual or span |
| CWSI digital zoom | 1 – 14x continuous |
| Software CWSI analyzer | Yes, included in the package |
| Digital visual camera | |
| Resolution | 1 920 x 1 080 pixels (Full HD), 1/3” sensor, Auto white balance, Wide dynamic range, Backlight compensation, Exposure and Gamma control |
| Optical zoom | 10x optical zoom with vibration compensation |
| View angle | Ultra zoom 6.9° - extra wide 58.2°, focal 33.0 mm - 3.3 mm |
| Noise reduction | Special 3D noise reduction function |
| Focus | Autofocus with Direct Focus Zoom synchronization |
| Memory and data recording | |
| Memory | Internal high-speed SSD 128 GB for image and video recording External slot for Micro SD card & USB 2.0 for USB stick for taking images |
| Image and video formats | CWSI JPEG images and Digital camera Full HD JPEG images Digital camera h.264 encode video HD recording Full-frame CWSI video recording (raw data recording) |
| GPS geo-tagging (image & video) | |
| GPS tagging (image & video) | MavLink or External GPS or DJI A3 controllers compatible via CAN bus |
| Interfaces & real-time remote control | |
| 10-pin digital port | S.Bus CAN bus (compatible with DJI M600 and A3 controllers) MavLink External GPS connectivity External trigger |
| Ethernet (RJ-45) port | Video streaming and camera control (optional on request only) |
| Micro USB 2.0 port | Mass storage Camera control and video streaming (optional on request only) |
| USB 2.0 port | Keyboard connection for in-house WIRIS camera control |
| Remote control system | CWSI OS ensures real-time control of all camera functions during the flight |
| Remote control options | S.BUS protocol CAN bus for real-time control on DJI M600 and GPS geo-tagging RJ-45 for wireless uplink installation (video streaming and camera control) |
| Protective filter on lens | Filter protects the lens against external damage during the flight |
| Camera functions | Measurement functions: - online CWSI evaluation - spot CWSI evaluation (Centre) - area CWSI evaluation (Max and Min) Periodic capturing: - capturing CWSI image and Visible image simultaneously |
| Camera modes visualization | Full-screen mode, Picture-in-Picture, Full Dual-screen, Dual-screen |
| Micro HDMI video output | 1 280 x 720 pixels (720p), Aspect ratio 16:9, Micro HDMI video output |
| Software & SDK | |
| Desktop software | Advanced Workswell CWSI analyzer for CWSI evaluation |
| Power supply, weight & dimensions | |
| Input supply voltage | 9 – 36 VDC, Coaxial 2 x 6.4 mm, outer shell - GND |
| Power dissipation (avg.) | 12 W |
| Weight | < 430 grams |
| Dimensions (L x W x H) | 83 mm x 85 mm x 68 mm |
| Mounting | 2 x 1/4-20 UNC thread (1x bottom side, 1x upper side) |
| Housing material | Durable aluminium body for long-time measurement stability |
| Environmental | |
| Operating temperature range | -10 °C to +50 °C |
| Storage temperature range | -30 °C to +60 °C |
| Formát | Název | Velikost | Odkaz |
|---|---|---|---|
 | Datasheet | 1,0 MB | DOWNLOAD |