How to Create User Defined NDVI Zones With The TerrAvion Zone Creation Tool
The TerrAvion NDVI zone creation tool allows users to turn high resolution NDVI maps into simplified, more actionable management zone maps that can be exported as shapefiles. These NDVI zoning maps can be easily incorporated into variable rate application plans, allowing growers to direct their resources to exactly where they will be most effective based on real-time data. NDVI zoning maps can also be used to form scouting, sampling and harvest zones.
Creating a TerrAvion NDVI Zoning Map In OverView
The TerrAvion NDVI zoning tool has two settings, a Basic setting that automatically sets the range of your zones, and a User setting that lets the user define the range of their zones. When creating a NDVI zoning map, it is important that the zoning map accurately reflects the NDVI imagery from which it is being formed from. For NDVI images that contain a lot a variation, the Basic zoning setting will suffice for creating a zoning map that accurately represents your NDVI imagery, but in most cases, using the User zoning setting is required to achieve accurate NDVI representation.
For more information on how to create a Basic NDVI zoning map, click here.
How to Create a User Defined NDVI Zoning Map
1. Choose the NDVI image from which you would like to make an NDIV zoning map. In most cases you will use the most recent NDVI image for in season treatments.
2. Once you have selected the NDVI image for which you would like to create a zoning map for, click the Zone Creation button.
3. Next, select User under the zoning type dropdown menu.
4. Select the number of zones for your zoning map.
5. Next, select the grid size for your zoning map. TerrAvion NDVI imagery is 18cm/pixel resolution. The NDVI zoning tool averages that fine NDVI data into larger grid blocks. In most cases, you want to make the grid size reflect the size of the piece of equipment you are planting or applicating with. If you have a planter/applicator that is 60 ft. wide, and the planter/applicator can apply different rates for each side of the boom, make your grid size 30 ft.
6. Next, use the histogram feature to the right of the zoning tool window to define your zones. Drag the adjustment buttons to define the range of NDVI values that will make up each of your zones.
7. As you adjust the histogram to form your zones, you will notice the the acres that make up each zone will change in the zoning tool window. The Cutoff section shows the cutoff point for each zone and is simply another way to adjust your zones, however we recommend that you make your adjustments using the histogram feature.
8. If you check the All button in the zoning tool window, you can preview the NDVI data that the zoning tool will be forming your zones from. Save time by using this feature to adjust your zones, preview them, and then make any additional adjustments before you create your zones by clicking the Calculate Zones button.
9. Use the Weight section to make any of your zones more prominent than others. If you really want to focus on a high vigor zone, or low vigor zone, increase the weight of those zones.
10. Use the Min Region Acres to filter out zones that are too small to act on. We recommend that you start by setting the Min Region Acres to .40
11. Click Calculate Zones to view your zoning map.
12. On the calculated zoning tool menu, turn off/on the All Zones button to gauge whether or not your zoning map accurately represents your NDVI imagery.
13. If you are not happy with how your zoning map represents your NDVI imagery, click back and adjust your histogram according to which zones you would like to be more prevalent on your zoning map. You can also change the weight of your zones to make certain zones more prominent.
14. When you are happy with your zoning map, you can make notes for each zone depending on how you intend to act on them. Click next to download a shapefile of your zoning map. (Please note that entering a value for your zones is not creating a prescription. Download your shapefile and import it into your prefered precision ag platform to make your prescriptions.)
15. In the export window, name your shapefile and check the Include Vigor Value box if you want to attach the NDVI data to your shapefile. Click Export to export your file.
TerrAvion strongly believes in the value of operating your farm based on “real-time” data, as do our growers. We encourage you to explore the possibilities of TerrAvion imagery in increasing your yields. If you are interested in making variable rate applications based on TerrAvion’s real time imagery data, and would like some guidance in how to do so, please contact us at firstname.lastname@example.org.