Satellite Technology and Agriculture

At the moment it is very frequent in Agriculture, the use of the denominated “GPS (global position system)” for the measurement of the coordinates of a point with much precision. The technique is based on the use of a set of satellites that make submetric accuracies possible.

Various applications in agricultural activity (pasture measurement, rural cadastre, yield mapping, fertilization strategies, among others) have called this methodology “Precision agriculture”.

Precision Agriculture is based on satellite technology, that is, GPS can achieve submetric accuracy through the position of satellites that orbit for this purpose. At present, there is extensive use, and the reader can know the characteristics of the technique through specialized articles or from private companies that sell the sensors.

What we will try to show in this article is a more general view of the use of satellites in Agriculture; indeed, in addition to allowing the measurement of the coordinates of a point on Earth, there are many satellites that carry sensors to measure different variables of the continents, the oceans, and the atmosphere, and through the data provided by some of them They deal with various issues that have to do with agricultural production and marketing. We are presenting what is usually called “Satellite Agriculture”.

When we addressed the structure and content of this article for the Rosario Stock Exchange, we were asked several questions. What kind of user should be targeted and what issues to deal with. The type of user in Agriculture is very broad (producer, stockpile, broker, seed company, agro-inputs, a trader, …). And among the most relevant points to develop are: What can we solve with Satellite Technology ?, How to solve them ? and then we come to the need to point out the techniques, sensors, and satellites that transport them. Undoubtedly, something that escapes the possibilities of the article. Finally, we choose to show which are the most used applications and present the earth observation satellites in their present and future state (until 2.002).

An earth observation satellite allows obtaining data from an area with a certain frequency (revisited), that is, the user can periodically obtain the data measured by the satellite in an area that he defines. These data are processed by a computer and allow you to identify the characteristics of land use at different times. For example, it can identify water cover, or it can discriminate the type of crop and its development.

The presentation of the results is an image of the area where you can see the characteristics of the region, and if you processed the information to identify a crop, you can see its distribution and the number of hectares it occupies. We are introducing ourselves in one of the main applications of satellite technology, such as crop estimation because if in addition to the area, the average yield of said crop is estimated, the production figure is reached, that is, you can know where is the crop, what is its status and its production in metric tons. This is very valuable information, both for the planning of a government and for the marketing strategies of said crop. And this applies today in the United States, in Europe and also in our country. As an example,

The applications are many, and among them, we can mention: crop monitoring (determination of planted areas and yields), hydrological monitoring (flood and drought situations), soil moisture status, determination of thermal situations (frost) and classification of use ground. And Satellite Agriculture allows addressing these problems both at the level of a field and an entire agricultural region. For this, there are several satellites with different resolutions (smaller objects that can be detected), various magazines and characteristics of how to observe the earth’s surface. We will deal with this in the following.

Earth observation satellites, present, and future

  • Satellite imaging has three basic characteristics that define a satellite observation system.
  • The geometric resolution, or measure of the smallest object that can be detected.
  • Temporary repetition period, or the speed at which a given area can be flown over and therefore obtain images. Generally, two types of repetition or revisit cycle are defined: on Nadir, which is the period in which the satellite can take pictures of the earth in full; and the revisit time, which is the period in which any area of ​​the earth can be “seen” again.
  • Spectral coverage, or the number and spectral range of the color bands of the sensor used.

We will present a summary of the information on the satellite systems of earth observation currently operational and those programmed to begin their operational phase before December of the year 2.002

Authors: José Luis Aiello – Carlos Daniel Caruso
Source: Institutional Magazine of the Rosario Stock Exchange