GRACE K-band signal-to-noise ratio (SNR) errors in range-rate residuals
Contributing to the ongoing efforts to reach GRACE baseline here we have investigated K- band range rate residuals. Range-rate residuals are dominated by the high frequency noise from the K-band ranging system. Further, we investigated the dominant error source in high frequencies. Our analysis shows that the high frequency errors (20-100 mHz) are due to low SNR values of K- band frequency of GRACE-B.
We found that SNR of GRACE-A also suffers with degraded performance but these errors are not seen in range-rate residuals. Degradation of SNR values are due to low temperature of GRACE instrument which is captured by the range-rate residuals. Contributing to the ongoing efforts to reach GRACE baseline here we have investigated K- band range rate residuals. Range-rate residuals are dominated by the high frequency noise from the K-band ranging system. Furthermore, we investigated the dominant error source in high frequencies. Our analysis shows that the high frequency errors (20-100 mHz) are due to low SNR values of K- band frequency of GRACE-B.
Figures 1 and 2(left) are showing the SNR errors due to low temperature. In Fig. 2(right), we show their impact on high frequency range-rate residuals for the test month of August 2007.
Fig. 1: GRACE-B temperature during August 2007.
Fig. 2: left) GRACE-B SNR during August 2007 , right) Range-rate residuals (high frequency noise only) of August 2007.
For more information about KBR SNR errors, please refer to MSc. Sujata Goswami, Institut für Erdmessung (IfE), Leibniz Universität Hannover.
