The Total Power Response to the Ground Radiation at 6cm Wavelength of the Urumqi 25m Radio Telescope at Nanshan Station

We present the result of intensive observations of the ground radiation around the Nanshan Station using the 6cm system of Urumqi 25m radio telescope.The response of the system to the ground radiation varies significantly in different directions of the sky.The response in the southwest direction, where there are many mountains, was saturated when the telescope pointed to the elevation of 8°;at the elevation of 60°, the response to the ground radiation still varied at a level of 0.3 K, larger than the system response to the Galactic Plane of 0.01~0.1K.Therefore the ground radiation affects the radio observation seriously.Using the observational data, we constructed a simple template of the ground radiation of the 6cm system in the directions of the sky.However, the accuracy of the template remains inadequate for real observations.