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. Workswell’s WIRIS Agro 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 and 10x optical zoom RGB camera with resolution full HD (1920 x 1080 px) for biomass cover index evaluation.
Main applications of WIRIS Agro
Although there are many uses, we can divide the main WIRIS Agro usage into these four 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 available.
- 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 available.
- Phenotyping – Different plant varieties are susceptible to the amount of water available. The WIRIS Agro will help you determine how often the plants of a given species are in water stress, compared to plants of other species.
- Biomass Cover Index – For realtime calculation of plant percentage on the field.
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 WIRIS Agro will help you to determine the actual and real effects of drought on the crop.
Comparison of CWSI and NDVI
Crop Water Stress Index
Normalized Differential Vegetation Index
Here you can download PDF document with full comparison of many other features of CWSI and NDVI.
With WIRIS Agro you 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 months and years depending on water stress, a potential yield map can be created according to the current water stress value.
- real-time onboard CWSI evaluation
- real-time CROP and WATER colour map vizualization
- real-time providing additional information on how the crop is really hit by drought
- real-time Biomass cover index evaluation in %
- real-time Picture-in-Picture CWSI index and RGB
Desktop Analysing Software CorePlayer for evaluation CWSI data
CWSI analysing software CorePlayer is a desktop software used for processing, analysing and exporting of CWSI RAW data images and videos. It allows to a user sets different parameters and models that are necessary for correct calculation of CWSI index or for later processing if the input data set to the camera needs to be adjusted.
For data processing to 2D or 3D vizualization can be also used the most common used SW tools such a Pix4D and Agisoft. Each image or video frame includes GPS information for processing.
The software is supplied free of charge to the WIRIS Agro.
Colour Map Overview
WIRIS Agro offers four different colourmaps. From the point of view of data and their processing it is not important which one of the colourmap you choose. In the application point of view a suitable palette choice can be very helpful.
Each colourmap in the WIRIS Agro camera is always defined in this way: the palette is black and white away from the value 0 (negative values below the range) and away from the value 100% (values above the range).
Biomass cover index
BCI (Biomass Cover index) is related to the evaluation of the mass of vegetation in the RGB scene. Based on data from the RGB camera, surfaces containing green vegetation are evaluated and the percentage of these areas is compared to other (non-vegetation) areas that are masked by white color in the RGB image. BCI is adjustable by simple thresholding by user.
Workswell WIRIS Agro Pro also brings an interface enabling the widest range of connections to the drone, the control unit, an external GPS sensor etc. Wi-Fi low latency live video streaming and command link is also available. The following HW interfaces are available:
- CAN bus (DJI M600 and A3 controller compatible)
- Ethernet (RJ 45)
- external GPS connection
- external trigger
128 GB SSD disk, external USB disk or microSD card
Workswell WIRIS Agro is equipped with an internal SSD disc with 128 GB memory for recording. It is also possible to save data to external USB disk or microSD card.
Weight and Dimensions
Workswell’s WIRIS Agro weighs less than 430 g, which is very convenient for drone usage.
WEIGHT: < 430 g
DIMENSIONS : 83 x 85 x 68 mm
|WIRIS Agro key features description|
|CWSI onboard processing||Evaluation of Crop Water Stress Index (CWSI) onboard in real-time|
|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
|Biomass cover index in %||Real-time percentage calculation of the mass of the vegetation in RGB|
|WIRIS Agro specification|
|Sensor resolution||640 x 512 pixels|
|Real-time CWSI evaluation||Workswell patented WIRIS Agro 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 – 100% (100% means very stressed)|
|Temperature sensitivity||0.03 °C (30 mK)|
|Field of view of the lens||45°|
|Color maps||4 color maps for CWSI and Water management evaluation|
|CWSI range settings||Automatic or manual|
|CWSI digital zoom||1 – 14x continuous|
|Software CorePlayer||Yes, included in the package 2 licenses|
|3D mapping SW compatibility||Agrisoft and Pix4D|
|10x Optical zoom digital visual camera|
|Resolution||1 920 x 1 080 pixels (Full HD),
Auto white balance,
Wide dynamic range,
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|
|Biomass cover index||Calculation of the index in real-time with Threshold 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)
External GPS connectivity
|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 including 4 different color maps
– spot CWSI evaluation (Centre) with temperature information
– biomass index evaluation in percentage in real-time
– capturing CWSI image, CWSI video and Visible image simultaneously
|Camera modes visualization||Picture-in-Picture, Full Screen RGB with segmentation, 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 CorePlayer for offline CWSI data analysis|
|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|
|Operating temperature range||-10 °C to +50 °C|
|Storage temperature range||-30 °C to +60 °C|
WIRIS Agro documents