Real-time sensing technologies

Control decisions for variable rate application can be implemented either on-line or off-line. In the on-line, or sensor-based approach, the controlled equipment incorporates onboard sensors and the sensor data are used immediately for automatic control. In the off-line, or map-based approach, data are collected and stored in one operation, and the controlled equipment uses the information in a separate field operation. The map-based approach allows more flexibility in data manipulation and pre-processing but requires multiple field operations. Most systems currently available are map-based, but more on-line systems will likely become available as real-time sensing technologies become more mature. Hybrid systems which rely on a combination of both mapped and real-time data may also come into more widespread use. 

Burdick J, Chase P, Faupel ML, Schultz B, Gebhart S. Real-time glucose sensing using transdermal fluid under continuous vacuum pressure in children with type 1 diabetes. Diabetes Technology Therapeutics 2005, 7, 488-455. 

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