How to modernize the Brewer and Dobson’s spectrometers to remove the aerosol error Asadov Hikmat Hamid, doctor of technical sciences, chief of department of Azerbaijan National Aerospace Agency Hasadzade firstname.lastname@example.org Azerbaijan, Baku, AZ1033, Azadlig ave. 159. ANASA As it can be seen from proceedings of the late XX Quadrennial Ozone Symposium one of the main questions arisen before space ozone measurement is to prove validity of space measurements by carrying out comparison with results of appropriate ground measurements. In more than 20 papers submitted to above Symposium it is stated that difference between two said measurements has reached approximately 1,5 – 2 % and further improvement of space measurements is limited by non – similarity of results of Dobson and Brewer spectrometers which are used as a basis for ground measurements. Henceforth, further improvement of space measurements of total content of ozone is useless till development of new methods, which should substitude obsolete Dobson’s method and its modifications. One of such methods was proposed by ourselves [1, 2, 3]. It should be noted, that proposed three – waves method is designated for ground ozone total content measurements and can be realized in two modifications: 1. Spectrometer with full compensation of aerosol error. 2. Spectrometer with full mutual compensation of aerosol error and error due to Reyleigh scattering. The algorithm of the method may be described as secuence of following steps: 1. To carry out measurements of solar flux in wavelengths 1 , 2 , 3 , where 1 2 3 , (may be 1 300 nm; 2 312 ,5 nm and 3 315 nm ). As a result we obtain relevant values of solar flux S1 , S 2 and S 3 . 2. To carry out following calculations S1 S 3 S rel 2 (1) S2 3. To change the value of 2 till meeting of following conditions: a) in the first modification of proposed method the aerosol error should be decreased down to zero by relevant selection of 2 . b) in the second modification of proposed method the aerosol error should be compensated with error due to Reileigh scattering by appropriate selection of 2 . Mathematical grounding of above is based on well – known Beer’s Law S S0 10 X m m1 (2) Where all used indices are well known and there is no necessity to describe them. Taking into account formulas (1) and (2) we have 1 3 3 1 3 S S X 2 m 1 2 2 S rel 0 1 0 3 10 2 2 2 (3) S0 2 It is obvious, that the first condition of above algorithm is met if 1 3 2 (4) 2 It is also obvious, that the second condition of above algorithm is met if 1 3 1 3 2 2 (5) 2 2 As a result we obtain main conditions making it possible to construct accurate three waves type spectrometers, where continual adjustment of wavelength 2 allow us to remove error components. References: 1. Patent of Azerbaijan Rebublic No. a20030134 dated 23.06.03. Three waves ozonometer. Authors: Asadov H.H., Isayev A.A. 2. Asadov H.H., Aliyev M.M., Isayev A.A.The universal theory of the three – waves ozonometric measurements “Physics” Journal of AzNAS Institute of Physics, V.X., 2004, p. 50. 3. Three waves method for measurement of total content of ozone. Full compensation of measurements error. Asadov H.H., Isayev A.A. Procedings XX Quadrennial Ozone Symposium, 1-8 June 2004, Kos, Greece, v.1, p. 477.