Stranica 50 [50]
OCR
] Object Incident Radiation Incident Radiation Blocked Radiation Radiation Radiation source source Transmitted Radiation Figure 2-1. Schematic representation of a generic set-up for the collection of multispectral images showing the main components reguired. The following sections offer a series of general recommendations on the selection of these components for each of the multispectral imaging technigues discussed. A list of typical (but by no means exclusive) suppliers used currently for such equipment has been included in Appendix 2 for reference. However, the aim is to provide guidance on the properties that the equipment selected should possess rather than to recommend particular items, models and/or brands. This should make the guidelines more widely applicable and less susceptible to become obsolete should production or availability of certain items/models cease. Table 2-1 summarises the equipment required by each imaging technique. As may be observed, the recording device and standards remain almost constant throughout, whilst the combination of radiation source and filter (or sets of filters) is altered to allow the study of the spectral windows of interest. Recommendations for the properties of the camera and standards are thus made in more general terms for all the techniques concerned, whereas the radiation sources and filters are discussed more specifically within the requirements of each particular technique. Version No. 1.0 Date : 14/10/2013 42
