用SGC053超导重力仪观测资料对gPh058重力仪格值的精密测定

ACCURATE DETERMINATION OF SCALE VALUE OF gPh058 GRAVIMETER BY USE OF OBSERVATIONS WITH SGC053 SUPERCONDUCTING GRAVIMETER

利用中国地震局武汉引力与固体潮观测站SGC053超导重力仪与gPh058重力仪的同址观测资料,采用切比雪夫多项式模型,利用同址比测方法对gPh058重力仪格值系数进行精密测定。对同址比测方法中的多项式阶数、采样数、采样时段3个可能影响格值系数的因素分析结果表明,重力仪的稳定情况是采样时段3个因素中影响最大的。计算不同采样时段的格值系数,取其加权均值作为gPh058的格值系数为:1.008 4±0.00 09×10-8ms-2/mV。格值系数的测定前后同址观测数据的分析表明:测定后gPh058重力仪可获得与超导重力仪相近的潮汐参数。经SGC053同址观测数据的漂移改正,残差周日波和半日波振幅只有测定前的1/4,而残差变幅只有±7×10-8 ms-2。虽然gPh058重力仪出厂前进行过标定,然而同址观测测定所获得的格值系数更加可靠。

Using same-site observations obtained with the SGC053 superconducting gravimeter and the gPh058 gravimeter in Gravitation and Earth Tide Observatory of China（GETOC）,the scale value（alias calibration factor） of the gPh058 gravimeter is accurately determined with the Chebyshev polynomial model.Through the analysis of regression order,sampling number,sampling time,the most obvious affect factor is the sampling time.The weighted average scale factor of different sampling times is 1.008 4±0.00 09×10-8ms-2/mV.Compared with the harmonic analysis before determination,the numerical results show that tidal parameters of comparatively high accuracy can be achieved with the gPh058 gravimeter.After determination,the amplitude of the residual with synthetic tide and drift correction is only 1/4 of that as before.Although gPh058 gravimeter had been calibrated in factory,the same-site determination should be more reliable.