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NDVI FAQs

Your questions answered about NDVI Satellite Spectral Imagery.


Sentek Technologies now offers an investigative tool exclusive to IrriMAX Live. Used by irrigators, IrriMAX Live presents a Google Map View of the selected property where water gauges and soil status are available.

NDVI images are high resolution satellite images taken throughout cropping season. This is an optional service, like the Weather forecasting service MeteoBlue (hyperlink). NDVI measures the state of plant healthy based on how the plant reflects light at certain frequencies. We utilise a range of satellite providers to get you the best images timely and cheaply. Our high-resolution offering provides you with insights at 0.4 or 0.5m granularity on a frequent basis.

As customers, you can see 2-3 high resolution images per month of your crops tracking over or underperformance. This will help you tackle irrigation management, fertigation practices, crop diseases and irrigation system performance issues.

Furthermore, building up this data over time is an investment that you can realise by improving overall yield quantity or quality, reducing input costs, or expanding into new varietals or paddocks.

We support any crop with a high amount of visible foliage. Our analysis works best for regularly spaced crops.

We can provide images around the globe. Almost all areas are suitable except for very cloudy regions as the satellite cannot see through the cloud. We have analysed remote valleys in the South Island of New Zealand (a.k.a. Land of the Long White Cloud) and will do our best to analyse your property.

We, Sentek Technologies, use third parties to acquire and process the images and analytics from multiple providers to get you the lowest cost and highest availability of satellite imagery.

We offer a selection of images providing information on plant health. This includes

  • Raw Normalised Difference Vegetation Index (NDVI). This gives you a simple score on how healthy your plants are.
  • Change in NDVI over time. This helps you understand how the crop is changing and whether different management strategies are working as well, or even better, than hoped.
  • Identification of high and low performing areas. This helps you determine which areas you may want to focus on to do tailored irrigation, fertigation, mulching, pruning etc.

You pay for a monthly service for each paddock that you want analysed. Multiple paddocks abutting each other can generally be analysed together.

We provide at least 1 image per month. Sometimes you may receive more due to weather and other conditions. If we cannot get 1 image for the month, e.g., due to cloud cover, then that month will be credited.

Yes. All these images are included in the standard monthly subscription.

Our high-resolution offering provides you with insights at 0.4 or 0.5m resolution. This allows problem solving at a per plant level.

Yes. Omitting the cover crops means all the analysis is only on the cash crop and is not biased by the health and prevalence of the cover crop. This is very helpful and a major benefit of this service.

After your service subscription, it will automatically appear in your IrriMAX Live account under “MAP” view.

Minimum contract time is 3 months.

It takes 3-5 days to surface an image. We present the images as-soon-as-possible onto IrriMAX Live, but it takes a few days for the images to download and be processed by the satellite imagery companies. Order your images 3 weeks prior to first access in IrriMAX Live.