Our overarching goal is to quantify the accuracy and reliability of geooptic S gnss data for space weather and its impacts on atmospheric retrievals. Specifically, we will evaluate how the vendor is…

This $88,653.72 federal grant award from the National Aeronautics and Space Administration (NASA) Shared Services Center to the Regents of the University of Colorado (University of Colorado) aims to quantify the accuracy and reliability of global navigation satellite system (GNSS) data for space weather monitoring and atmospheric retrievals. The University will evaluate how the GNSS vendor treats ionospheric contributions to excess phase, which serves as a remote diagnostic of space weather. Key tasks include analyzing GNSS phase noise performance, cycle slip mitigation, and comparisons to other GNSS datasets and ground instruments. The University has relevant expertise in GNSS data processing, ionospheric physics, and related applications. This grant does not have a set-aside designation.

Our overarching goal is to quantify the accuracy and reliability of geooptic S gnss data for space weather and its impacts on atmospheric retrievals. Specifically, we will evaluate how the vendor is treating the ionospheric contributions to the excess phase that need to be subtracted before receiving the atmospheric refractivity and bending angle. This information, in turn, serves as a remote diagnostic of the space weather. These parameters are critical system science observations in the low and upper atmosphere, used in weather and space weather data assimilation schemes addressing the NASA earth science strategic goal further the use of earth system science research to inform decisions and provide benefits to society. : we will quantify the derivation of the POD TEC and RO TEC using 100 HZ phase and SNR data to evaluate the noise performance and cycle slips. The RO signal processing adopts an open loop tracking approach thus the internal noise performance is robust to environmental disturbances. The noise performance analysis can be performed under a quiet ionosphere condition, and IT provides information about RO receiver hardware and signal processing performance. A better phase performance leads to a lower cycle slip occurrence even with ionospheric scintillation, assuming the same post-processing procedures. The cycle slips impact both the low-rate (POD TEC) and high-rate (RO TEC and ionprf) data products, and different cycle mitigation techniques should be applied to low-rate and high-rate phase data. (1) we will evaluate the phase noise performance and cycle slip mitigation using the scanf algorithm. We will analyze periods of high magnetic disturbances to evaluate the contributions of scintillation to the receivers' noise performance and their treatment and will connect these observations with geophysical phenomena. (2) we will compare the quiet time POD TEC with cosmic-2 and spire conjunctions to evaluate the vendor's calibration of absolute TEC routines. (3) we will evaluate the accuracy of the L2 density retrievals ionprf by comparing the NMF2 and HMF2 with cosmic-2 and spire gnss RO conjunction, ground-based ionosondes and whole density profiles with incoherent scatter radars. The team members have the necessary experience processing I/Q and rinex gnss data and participated in the evaluation of spire data from the previous cnvoe solicitation. The PI, DR. Mrak has experience with ionospheric space weather remote sensing including the ISR and gnss-TEC. The CO-I DR. Wang has extensive experience processing I/Q gnss data for RO and gnss-reflectometry applications. CO-I LEI LIU is currently evaluating the spire density profiles.