The GPS Radio Occultation and Ultraviolet Photometry—Colocated (GROUP-C) Experiment on the ISS
Abstract
The GPS Radio Occultation and Ultraviolet Photometry—Colocated (GROUP-C) Experiment is an ionospheric remote sensing experiment manifested to fly on the International Space Station in early 2016. GROUP-C will operate aboard the Space Test Program Houston 5 (STP-H5) experiment pallet and provide ionospheric measurements in real-time. GROUP-C includes two sensors: the Fast Orbital TEC, Observables, and Navigation (FOTON) L1/L2 GPS receiver, which provides vertical electron density profiles and scintillation; and the Tiny Ionospheric Photometer (TIP), a far-ultraviolet photometer for measuring horizontal ionosphere gradients. The FOTON receiver includes a capability for multipath mitigation using a multi-antenna array. The TIP photometer is similar to the photometers aboard the COSMIC satellites with minor improvements in optical performance.Ionospheric irregularities, also known as ionospheric bubbles, are transient features of the low and middle latitude ionosphere with important implications for operational systems. Understanding irregularity formation, development, and evolution is vital for efforts within NASA and DoD to forecast scintillation. Irregularity structures have been studied primarily using ground-based systems, though some spaced-based remote and in-situ sensing has been performed. In combination with GROUP-C, the Limb-imaging Ionospheric and Thermospheric Extreme-ultraviolet Spectrograph (LITES) experiment on STP-H5 will serve as an interactive ionospheric observatory on the ISS. These experiments would provide new capability to study low- and mid-latitude ionospheric structures on a global scale. By combining for the first time high-sensitivity in-track photometry with vertical ionospheric airglow spectrographic imagery, and simultaneous GPS TEC and scintillation measurements, high-fidelity optical tomographic reconstruction of bubbles can be performed from the ISS. Ground-based imagery can supplement the tomography by providing all-sky images of ionospheric structures (e.g. bubbles and TIDs) and of signatures of lower atmospheric dynamics, such as gravity waves, that may play a role in irregularity formation.
- Publication:
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AAS/AGU Triennial Earth-Sun Summit
- Pub Date:
- April 2015
- Bibcode:
- 2015TESS....110904B