Captain, sensors report ...: Correction of Remote Sensing Data

Remote sensing data acquired by airborne and satellite Systems have many impressive virtues for ecology and other sciences. They are synoptic. They are extremely cheap per data point. They cover large areas. They are not subjective. They detect features that are of clear and obvious interest for many uses. But, they also yield totally irreproducible measurements. Sensors that operate in the visible, near infrared and thermal portions of the spectrum are sensitive to a host of phenomena that are usually of little interest to the average user. Fully recognizing the power and sophistication of the algorithms currently available to users of remote sensing, the authors as long time developers (20+ years) of such algorithms, demonstrate that a host of other signals are convolved with the typical data set, and that many of these signals are very commonly not even recognized, and that these signals are often larger than the signal from the putative target. These derive from both geometric and radiometric sources as well as fundamental flaws in sensor engineering. Until such extraneous factors can be controlled or eliminated the utility of the data is greatly restricted. Finally, the authors lay out a design elements for a rational sensor and methods of deconvolving the complexity of the real world data using such a sensor.