Emitted Nocturnal Infrared

Among numerous other observations, those of the eastern regions of the Caspian Sea area seem to me to be of the greatest geopedological and paleogeomorphological interest. In this respect, two facts must be brought out. 

In addition, and this is something constantly found on most of the Nimbus orbits, one can imagine a former link between these two inland seas perhaps even a second at a higher latitude. 

For the record, I will cite one negative fact Syr-Darya and Amu-Darya do not appear on this map whereas, with reflected infrared, these rivers are faintly (Syr-Darya) and strongly (Amu-Darya) brought out. On these same maps in the 0.8-1.3 pm spectral band, the tectonic features in the immediate vicinity of Nukus show up particularly well (Pouquet, 1970, San Francisco and Tucson). The reason I make this comment is to draw the reader s attention to an imperative rule for all remote detection studies the need to analyze as many orbits as possible for the region in question, by analyses of the various spectral bands we have available. 

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For the same reasons, we arrive at rule No. 5, somewhat comprable to principles 3 and 4 of nocturnal emitted infrared. This third principle is difficult to express. We can state it as follows at midday, light objects are warmer than dark objects., with three important exceptions. First, this remark only applies in sunny weather, the only kind of weather in which the satellite s radiometer can take measurements. Second, this rule is observed and modified by petrographic textures. A fine-textured rock is colder than the coarse-textured rock of identical composition, and vice versa. Thus, a dark, fine-textured rock can be at the same temperature level as a light, very coarse-textured rock. Finally, if the sun has been out only a few moments before the satellite passes (sudden cleaning of a cloud ceiling) we are in a situation halfway between nocturnal and diurnal radiation characteristics. 

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