Satellite and aerial imagery play a significant role in modern day agricultural production and forest related activities. T he primary value of satellite and airborne imagery to agriculture and forestry is two-fold. Firstly, imagery provides valuable information that is useful for planning and managing the potential crop output, in a sustainable way. Imagery results in more sustainable food production. Secondly, imagery enables the gathering of knowledge about agriculture and forestry through local to regional to global scales. That knowledge enables a better understanding of overall production factors, but also contributes toward risk management decisions and supports predictive modelling of food supply and consumption. This article gives a thorough account of the applications of satellite imagery and GIS used in the agriculture and forestry sectors.(Vector1media, 13 May 2011)
Over the last decade, remote sensing has developed in various ways, strongly increasing its potential as a tool to support integrated agricultural management and sustainable rural development.First of all, geometric or spatial resolution has improved which implies that smaller details on the ground become visible, allowing for a better view of vegetation and its surrounding environment. Second, the improvement of the radiometric or spectral resolution combined with the integral use of information from different spectral channels allows a more accurate analysis and interpretation of the Remote Sensing data in terms of: type of crop, soil type, state of growth, and presence of disease. Moreover, this aspect facilitates the use of Remote Sensing data under less favourable atmospheric conditions. Thirdly, the number of operational Remote Sensing platforms is growing, which allows for almost continuous monitoring at a worldwide scale.Finally, the internet with its ever increasing capabilities has strongly facilitated the availability of Remote Sensing data and derived data and information products to users, even in remote places.
Remote imaging sensors use electromagnetic radiation, emanating from the earths' surface, either directly (thermal radiation: temperature) or reflected by it. There are two main types; active and passive. In the latter case the source is sunlight (visible light scanners) or an artificial source carried by the sensing platform (radar, lidar). Remote Sensing uses radiation with wavelengths roughly between 400 nm (ultraviolet) and 4 cm (radio waves).
Rapid developments in technology within the last decades of the 20th century are contributing to more informed decision making on issues related to environmental and resource management and agricultural and rural development. Remote Sensing, i.e. geo-spatial technologies for observations from airborne and space borne platforms , is one of these new developments.New sensors and sensor systems were developed that allowed more detailed information to be accessible. Technology systems became smaller (nanotechnology), faster, more versatile, more user-friendly, and to a certain extent even 'intelligent'. The observations made from altitudes between 100 m and 36000 km provided a unique overview and allowed for the identification of large units and relationships to be determined. It would never have been possible to obtain this overview merely from field observations.
Operational and independent application of Remote Sensing technology requires in each ACP country the implementation of a complete chain of technology infrastructure, from acquisition of the Remote Sensing data (either by purchase or by direct reception), through processing and generation of information products, to distribution to specific users and applications. Investments need to be made in the necessary equipment for receiving and processing Remote Sensing data, and for converting these data into specific, dedicated information products for science and decision-making. The information products generated need to be directly tuned to the requirements of the users and their applications. An appropriate organisational structure needs to be established in order to operate the acquired technology for the benefit of the country.