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Which is the correct value for the NDVI index?
The NDVI is a simple index to interpret: its values vary between -1 and 1, and each value corresponds to a different agronomic situation, regardless of the crop (Table 1). Table 1: Agricolus NDVI index. The average NDVI of a field varies according to the variety and phenological stage of the crop.
What does the NDVI of a field mean?
The NDVI is a simple index to interpret: its values vary between -1 and 1, and each value corresponds to a different agronomic situation, regardless of the crop (Table 1). The average NDVI of a field varies according to the variety and phenological stage of the crop.
Which is the best app for NDVI and ndmi?
Agricolus Free, the free solution for getting started with precision farming, offers Imagery feature for both the entire farm and specific field. It makes available NDVI and NDMI calculated from Landsat data, which is present all over the world: the indices can be consulted for all the acquisition dates of the last 365 days.
How are the NDVI and ndmi vegetation indices reported?
They are reported in classes of absolute values, already interpreted, to allow the comparison of the different plots. While in the “Fields” feature, in the Imagery tab, it is possible to display both indices reclassified into 5 relative value classes, in order to identify the most problematic areas of each field.
What does a high NDVI mean for vegetation?
Higher values signify a larger difference between the red and near infrared radiation recorded by the sensor – a condition associated with highly photosynthetically-active vegetation. Low NDVI values mean there is little difference between the red and NIR signals. This happens when there is little photosynthetic activity,…
How does the NDVI of a field vary?
The average NDVI of a field varies according to the variety and phenological stage of the crop. In a field, where a crop tends to be at the same phenological stage, areas with a significantly lower than average NDVI value present problems in vegetative development, for example:
What should the NDVI of a desert be?
NDVI values range from +1.0 to -1.0. Areas of barren rock, sand, or snow usually show very low NDVI values (for example, 0.1 or less). Sparse vegetation such as shrubs and grasslands or senescing crops may result in moderate NDVI values (approximately 0.2 to 0.5).