PixAgri :: Understand

MINI FAQ

What crops does Spot Image work with?

Green leaf cover fraction is a universal indicator applicable to any type of crop. It offers a dynamic, precise picture of crop management based on absolute values, so you can compare fields, regions or years to suit your needs.
PixAgri is already operational for wheat, barley, rape, sugar cane, maize, sunflower, soya bean, legumes, sugar beet and sorghum.

What benefits can you expect?

Calculating benefits is difficult, as they will depend on the country and above all on growing conditions. Each field has its own climate, crop, cultural practices and yield objectives. Economic benefits therefore vary from one farm to another.
Our crop science and remote sensing domain experts will of course help you to establish trends from maps delivered and ground truth.
Analysis of these maps generates direct quality benefits by helping you to optimize investment and effort through:

Farm diagnosis: inter-field and sub-field variations, identification of sources of variability, analysis to determine whether practices fit objectives.
Support in optimizing practices to meet your short- and medium-term objectives.
Monitoring implementation of new practices and their effectiveness.

How do PixAgri tools fit in with your current way of working?

At Spot Image, we combine experience in the field with sustained R&D to nurture a customer-facing approach and adapt our products and services to the way you work.
Our maps are delivered in image formats (GeoTIFF, etc.) compatible with most geographic information software, thus allowing you to conduct sub-field and inter-field analysis from your office or in the field. Map files are interoperable and supported by a range of mobile and on-tractor systems.
We also deliver fully annotated and printable maps in PDF format, giving you a strategic picture of crop condition at field level. And sub-field detail allows you to adapt seed density and application of inputs (water, fertilizer, etc.) to each crop.
Our products provide you with a level of ground detail of 2 metres. The colour palette is always the same. If you wish, we can supply you with a GIS so you can view and exploit PixAgri maps on mobile or in-vehicle systems.

How reliable is this tool?

Spot Image has developed a proprietary software application called Overland™ , which uses a unique image processing methodology that doesn’t depend on local and weather conditions. Because we understand that you need reliable information, at the right time and in the right place, our crop science domain experts work with you and systematically check maps before they are delivered.

What sensors do we use?

Spot Image covers the whole value chain from the choice of sensor to customer service.
Our domain expertise in remote sensing and crop science means we are able to choose which of the SPOT 4, SPOT 5, FORMOSAT-2, KOMPSAT-2, DEIMOS and UK-DMC2 satellites will best meet your needs in terms of resolution and imaging swath.

Do special conditions apply to benefit from this service?

We use a special graphic format to map the fields you want to monitor by satellite. PixAgri is designed to be easily accessible, which is why we offer the Geo Pack to provide the basic tools to keep track of your fields with satellite imagery.

Tutorials

Remote sensing as an aid to crop management

The advantage of satellites for agriculture is their ability to collect reliable data on crop condition and pinpoint spatial and temporal variations.
The farmer and his/her advisers use such information about biophysical variables to adjust cultural operations and establish a diagnosis through :

field comparisons to guide production management and optimization decisions
sub-field analysis to optimize seed density, fertilizer, water and other inputs

Satellite data are employed in precision agriculture to manage and monitor farming practices at national, regional, local and field levels. Such broad coverage provides a detailed picture of spatial distribution of farmland, changes in land use, effectiveness of agricultural policies, production management and farm optimization, spatially-enabled management of technical operations, optimization of logistics and more besides.

parcels seen from above (click to enlarge)

Our method

A universal indicator for close crop monitoring
Spot Image has invested 15 years of R&D effort to develop a unique tool for analysing plant cover.
Our proprietary Overland™ software processes satellites imagery automatically to estimate biophysical parameters characterizing crop status and structure. This upgradable tool can be configured for different sensors, types of vegetation, areas of interest, types of soil and viewing conditions. What makes it unique is the methodology employed to provide parameters that do not depend on local conditions and viewing conditions.
This novel approach allows you to map your crops’ biophysical properties in ways that are:

measurable in the field
temporally and spatially comparable
compatible with agronomic models

PixAgri map products pinpoint temporal and spatial variations in plant cover characteristics between fields or at sub-field level. These maps support diagnosis of crop condition across all fields and tracking of changes throughout the growing campaign.

crop monitoring process (click to enlarge)

Biophysical parameters

Green Leaf cover fraction (GLCV)
This parameter quantifies the surface area of green vegetation visible at nadir within 1 sq.m of soil. It varies from 0 (bare soil) to 1 (total green cover) and has no unit.

Zoned green leaf cover fraction (ZGLCV)
This parameter is obtained by segmenting field-level maps of green leaf cover fraction. The resulting maps delimit uniform areas within fields and can be used in particular to adjust application of inputs.

GLCV map (click to enlarge)

ZGLCV map (click to enlarge)

Field boundary mapping

Field boundaries are entered from satellite imagery with reference to fixed features, such as observable physical boundaries.
Information specific to each cultural unit is then tied to this digital outline.
The set of files thus obtained goes into the field database used by our specialists to generate PixAgri maps.
The database can be compiled by Spot Image or by a distributor and supplied with Geo Pack, or you can compile it yourself. Yearly updates can also be provided.

plot delineation (click to enlarge)

Remote sensing and agriculture

Our method

Biophysical parameters

Field boundary mapping