One of the most valuable PA tools on the market today is satellite imagery. With new satellites seemingly being launched almost on a weekly basis, satellite imagery will only get better, cheaper, and more accessible.
We offer 3 satellite imagery products, at different resolutions. These are:
After capturing of the imagery, we process the imagery to create vegetation indices, and then clip these to the paddock or farm boundary, to bring out differences in crop growth. This is then delivered to the farmer electronically. After harvest, the yield data (or other spatial data) can be compared with the imagery using our sophisticated GIS tools. Trial information can be easily extracted to look at the response of the crop to certain treatments.
Satellite imagery captures the light reflecting from crops/plants through a scanner, not a camera. “Bands” are certain wavelengths of light which are captured by the scanner, and a kept as separate files until combined at a later date, in either the form of true colour images (composites), or indices (such as NDVI).
Below is a representation of the reflectance values (blue line) of a healthy crop. You can see on that the healthy crop, there is low blue and red reflectance, and a slight jump in the green band – the reason why healthy crops appear green. The first grey colour band (between 720-900nm) is the Near Infrared (NIR) light, which is beyond our visible spectrum.
NIR is critical for measuring the health, vigour, and biomass of crops remotely. The point at which the blue line jumps rapidly between the red and NIR bands is called the “red-edge”. It is not completely clear as to what the “red-edge” is telling us about a crop, but we are actively researching the applications of this part of the spectrum.
Source: www.cropscan.com
We offer 3 satellite imagery products, at different resolutions. These are:
- iSAT0.8 – which a 0.8m pixel image product which provides a highly detailed look at micro differences happening in the field. We can see every little detail about the crop, and it is always astounding to see the impact of micro-variation on crop productivity. This satellite product is also good for evaluating trials. There is considerable archive available for this satellite (good for farm maps) however we normally task the satellite to capture at a certain time in the crops growth. Free quote click here.
- iSAT5 – this is a new satellite which is primarily designed for the PA market, and has a pixel size of 5m x 5m. It has the red-edge included, which may give us new insights into crop health. This imagery is useful for zoning and in-crop applications of crop protectants, nutrients, and even desiccation where appropriate. Free quote click here.
- iSAT30 – is a medium resolution image product of 30m. Whilst it is fairly coarse for precision agriculture, it cost effectiveness means that we can do a whole farm or catchment relatively cheaply. Its primary use is it to examine long-term trends over the property or catchment, as images are captured regularly regardless of ordering. Free quote click here.
We also offer a "stacked" NDVI farm map which is created by averaging between 3 and 7 iSAT30 images captured during peak crop biomass.
This map represents areas of high, medium and low crop biomass (as seen below). It is a valuable dataset which allows farmers who do not have multiple yield maps to start developing a variable rate management plan.
The map can be used to identify variation within paddocks and between paddocks.
This "stacked" NDVI map can be applied to any farm in the world for just $700. To order just click here.
This map represents areas of high, medium and low crop biomass (as seen below). It is a valuable dataset which allows farmers who do not have multiple yield maps to start developing a variable rate management plan.
The map can be used to identify variation within paddocks and between paddocks.
This "stacked" NDVI map can be applied to any farm in the world for just $700. To order just click here.
After capturing of the imagery, we process the imagery to create vegetation indices, and then clip these to the paddock or farm boundary, to bring out differences in crop growth. This is then delivered to the farmer electronically. After harvest, the yield data (or other spatial data) can be compared with the imagery using our sophisticated GIS tools. Trial information can be easily extracted to look at the response of the crop to certain treatments.
A little bit of detail on why satellite images are different to photos
Satellite imagery captures the light reflecting from crops/plants through a scanner, not a camera. “Bands” are certain wavelengths of light which are captured by the scanner, and a kept as separate files until combined at a later date, in either the form of true colour images (composites), or indices (such as NDVI).
Below is a representation of the reflectance values (blue line) of a healthy crop. You can see on that the healthy crop, there is low blue and red reflectance, and a slight jump in the green band – the reason why healthy crops appear green. The first grey colour band (between 720-900nm) is the Near Infrared (NIR) light, which is beyond our visible spectrum.
NIR is critical for measuring the health, vigour, and biomass of crops remotely. The point at which the blue line jumps rapidly between the red and NIR bands is called the “red-edge”. It is not completely clear as to what the “red-edge” is telling us about a crop, but we are actively researching the applications of this part of the spectrum.
Source: www.cropscan.com
