Sensing by electromagnetic radiation

Abstract

Electromagnetic radiation lends itself to non-contact sensing of many soil- and crop properties. The basis for this is that theoretically any matter - including constituents of soils and crops - can be identified by an electromagnetic index that is derived from its radiation. This electromagnetic index can act as an optical fingerprint of the respective matter or constituent. Sensing from satellites or from aerial platforms allows obtaining maps that provide an overview within approximately the same time about soil- or crop properties from fields or from wider areas for tactical inspections. Sensors that are located on farm machines never can do this, let alone because of the time it takes to cover a wide area. Yet when it comes to the control of site-specific field operations, sensors on farm machines can provide the best spatial- and temporal precision that is possible. Their excellent spatial precision results from the low distance to soils or crops. The high temporal precision is possible since the signals are recorded just in time. This is important for those soil- and crop properties that vary fast in time. Georeferencing by positioning systems allows storing site-specific signals.