Sensor applications, remote

In addition to the fiber sensors, there have been numerous reports on remote fiberless optical detection of pollution from stationary sources. Mobile remote sensors can have cost advantages over on-site instruments and also are much more versatile. Pollutants in smokestack emissions have been identified by irradiation with a laser from a mobile unit equipped with a telescope, a monochromator, and low-noise detection electronics. The gases and particles in the plume scatter the laser light in various directions. A fraction is scattered back to the receiver and analysed to detect the amount and type of gas in the plume. Many of these methods await their application to fiber-optic sensing schemes which are inherently safer than direct laser spectroscopic schemes. 

In many remote-sensing applications the number of measurements Nf exceeds the number of retrieved parameters This is characteristic of new advanced sensors with multi-spectral, multi-angle [20-23, etc.], and polarimetric... 

Traditionally, most MFCs are in macro- or mesoscale forms that aim for wastewater treatment and renewable energy production, bioremediation, and power supply for remote sensors in harsh conditions. Another interesting application is via miniaturization of an MFC to be microscale, a small-size power supply. 

The principal component analysis (PCA) or Karhunen-Loeve analysis is useful for analysis of highly correlated multi-spectral remotely sensed data [13, 14]. The transformation of raw remote sensor data using PCA can result in new principal component images that may be more interpretable than the original data [14, 15]. For PCA the transformation is applied to a correlated set of multi-spectral data, application of the transformation to the correlated remote sensor data will result in another uncorrelated multi-spectral dataset that has certain ordered variance properties. This transformation is conceptualized by considering the two-dimensional distribution of pixel values obtained in two bands that can be labeled as and X. The spread or variance of the distribution of points is an indication of the correlation and quality of information associated with both bands, if aU the points are clustered in an extremely tight zone in two-dimensional space, these data will provide very little information. 

Application Rexibility Non-intrusive calibration, mounting orientation options, remote sensor, and with the FieldServer option, interface to a choice of over 75 communication protocols. 

Optical fibres can be used in the transmittance and ATR mode (a special ATR application is the remote sensor), and even in the reflectance mode. The development of special optical fibres for transmission, transflection or diffuse reflectance measurements favours on-line analysis of problematic product streams and reaction mixtures (solutions, suspensions, emulsions, melts, solids). Both quartz and fluoride (ZrF4-based) glass fibres are used, with the former having poor transmission characteristics above 2000 nm. 

Applications of emission sensors can be found in remote sensing of hot, gasous samples, in particular (industrial) exhaust gases. 

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