Narcotics research, rehabilitation, and treatment. Hearings, Ninety ...

;86Figure 3.—Tones of wheat (W) and oats (O) differ when recorded by an airbornemultilens camera filtered to three spectral regions (0.38 to 0.44 micron, at left0.62 to 0.68, center; and 0.58 to 0.89, at right).[Data Collected by Purdue University Agronomy Farm.]to include simultaneous observation in many spectral bands and computeranalysis of the data.I am not aware of opium poppies having been observed by thesemethods, but it is reasonable to expect that they would be readily discernible;perhaps even by single band, rather than multispectral, sensing."VVliat is needed is a set of experiments to establish which approachproduces the desired information with reference to opiumpoppy cultivation. It should be possible to use either an establishedpoppyfield or a specially prepared one and to overfly it with equipmentdesigned for spectral analysis. The signatures of poppies couldthus be obtained and examined for uniqueness. Once unique, characteristicimages are obtained from the test bed, the appropriate apparatuswould be used in an operational test to determine what, if any,real-life difficulties might be encountered. Further refinement of thetechnique would follow.Remote sensing from aircraft is very likely to be successful in locatingopium fields. Similar observations from satellites, particularlyfrom NASA's Earth Resources Technology Satellite (ERTS), aresomewhat less certain to produce useful results. The multispectralsensing devices on the initial ERTS spacecraft will provide resolutionof objects down to about 300 or 400 feet. The smallest opium fieldsare said to be about i/^ acre or typically about 150 feet in linear dimension.It is possible, but not at all certain, that a distinctive signatureof that size will be discernible by an instrument with the resolutionavailable on ERTS. Needed is experimental determination of thepoppy signatures and some experience with the real capabilities of theERTS instruments. We must also consider future instruments thatmay provide finer resolution and other favorable characteristics.Trace?' TechnologyTracers, or tag identifiers, can be used to identify captured samplesas coming from the same sources. It may be possible to introduce trac-