Satellite Remote Sensing Use Case

by Sergej Lugovic

March 11, 2022

U suradnji s tvrtkom LI:ST Geoinformatika zadnjih par godina razvijamo rješenja za upotrebu satelitskih tehnologija za potrebe poljoprivrede. Niže je naveden primjer jedne parcele. Text je na engleskom jer za sada uglavnom imamo upite s međunarodnog tržišta.

Normalized Difference Vegetation Index (NDVI)

Calculation of the Normalized Difference Vegetation Index (NDVI), which is available on-the-fly, comes first. In addition, NDVI is often used around the world to monitor drought, forecast agricultural production, assist in forecasting fire zones and desert offensive maps. Farming apps, like Crop Monitoring, integrate NDVI to facilitate crop scouting and give precision to fertilizer application and irrigation, among other field treatment activities, at specific growth stages. NDVI is preferable for global vegetation monitoring since it helps to compensate for changes in lighting conditions, surface slope, exposure, and other external factors.

This index defines values from -1.0 to 1.0, basically representing greens, where negative values are mainly formed from clouds, water and snow, and values close to zero are primarily formed from rocks and bare soil. Very small values (0.1 or less) of the NDVI function correspond to empty areas of rocks, sand or snow. Moderate values (from 0.2 to 0.3) represent shrubs and meadows, while large values (from 0.6 to 0.8) indicate temperate and tropical forests.

Parcel Normalized Difference Vegetation Index (NDVI) - (01/20 do 12/20)

The NDMI (Normalized Difference Moisture Index)

The NDMI (Normalized Difference Moisture Index) describes the crop’s water stress level and is calculated as the ratio between the difference and the sum of the refracted radiations in the near infrared and SWIR, that is as (NIR-SWIR)/(NIR+SWIR). The interpretation of the absolute value of the NDMI makes possible to immediately recognize the areas of the farm or field with water stress problems. NDMI is easy to interpret: its values vary between -1 and 1, and each value corresponds to a different agronomic situation, independently of the crop.

Parcel Normalized Difference Moisture Index) (01/20 do 12/20)

Normalized Difference Water Index (NDWI)

Vegetation cover on the Earth’s surface undergoes severe stress during a drought. If affected areas are not identified in time, entire crops may be damaged. The early detection of water stress can prevent many of the negative impacts on crops. Remote sensing of land and the NDWI index can control irrigation in real time, significantly improving agriculture, especially in areas where meeting the need for water is difficult.

Parcel Normalized Difference Water Index (NDWI) - (01/20 do 12/20)

FES index

Iron is an indicator for soil fertility and the usability of an area for cultivating crops. Remote sensing is the only suitable tool for surveying large areas at a high temporal and spatial interval, yet a relative high spectral resolution is needed for mapping iron contents with reflectance data.

Parcel FES index - (01/20 do 12/20)

Parcel Slope

Parcel Aspect

Parcel Elavation