Beijing, March 16 : Chinese researchers have achieved neutral atmospheric density in the altitude from 90 to 200 kms, according to a recent research article published in the journal Advances in Space Research. The near-space atmosphere is simultaneously influenced by solar and geomagnetic activities, as well as topography, weather, and gravitational waves, Xinhua news agency reported. As a basic parameter to characterise the near-space atmosphere, the density of the near-space atmosphere can be used to analyse the physical mechanism of the sun-earth relationship and the coupling of the circle layer. Space vehicles pass through the near-space atmosphere. The accurate measurement of near-space atmosphere density affects the precise orbiting, avoiding space debris collision and the re-entry control of spacecraft. The X-ray Earth occultation realised tomographic scanning of atmosphere density in near space by using a satellite platform and effectively operated the global real-time detection. With the occultation data of China's Hard X-ray Modulation Telescope (HXMT), the researchers from the Chinese Academy of Sciences found that the atmospheric density retrieved by the new method is qualitatively consistent with previous independent X-ray occultation results, which are also lower than empirical model predictions, noted the research article. In addition, the accuracy of atmospheric density retrieved results decreases with the increase of altitude in the altitude from 150 to 200 kms. /IANS