500 
Let’s consider the method of estimating the proper season of 
aerial photography. In the desert the maximum optical contrast between the 
natural objects is observed in spring. So in sand deserts spring is the 
most suitable season of aerial photography. The beginning and end of this 
period have been estimated on spectral reflectance data and phenology of 
indicator plants. 
As indicator plants have been taken Haloxylon pevsicnm and 
Carex physedes. In the phenological chart (Fig. 3) the beginning of the 
vegetative stage of Haloxylon persicum is shown, with intervals of 10 days. 
To estimate the beginning of the proper season of aerial photography 10 
days should be added to the isophene. 
The second phenological chart (Fig. 3) shows the approach of 
Carex physedes withering. Simultaneously all other ephemeres and 
ephemeroids wither up. 
Aerial camera is the most widely used remote sensor in the 
desert zone. It is obvious that another remote sensor can be used here. 
Mathematical treatment of data has shown spectral bands in which the greatest 
number of objects can be identified in aerial photos. The spectral bands 
providing the maximal contrast are the following: 1. in the sandy desert 
400 - 525 nm and 600 - 675 nm, 2. in the foothill country 400 - 500 nm and 
620 - 680 nm, 3. in the man - made landscape 600 - 675 nm and 750 - 850 nm. 
One can suppose that using multispectral technique will give 
good results by obtaining imagery in spectral bands mentioned. 
LITERATURE CITED 
Kol'tsov V.V. Spektrofotometricheskie kharakteristiki elementov zemnoi 
poverkhnosti i ikh izmerenie dlya tsolei aerofotos”emki (Spectral 
reflectance properties of landscape elements and their measurements 
for aerial photography). Isaledovanie opticheskikh svoistv 
prirodnykh ob”ektov i ikh aerofotograficheskogo izohrazheniya. Izd. 
Nauka, L., 1970. 
Kharin N.G. Lesokhozyaistvennoe deshifrirovanie aerosnimkov (Forest photo - 
interpretation). Izd. Nauka, M., 1965. 
Kharin N.G. Karty sezonnogo razvitiya pustynnoi rastitel'nosti 
(Phenological charts of desert plants). Izvestiya AN Turkm. S.S.R. 
(ser. biol.), 1966, N. 5. 
Billings W.D. and R.J. Morris. Reflection of visible and infrared radiation 
from leaves of different ecological groups. Am. J. Bot., 1951, Vol. 
38, N. 5. 
Howard J.A. The reflective foliaceous properties of tree species. Appl. 
Remote Sensors in Forestry. Freiburg, 1971.