Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2507.08823 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866915932619669504 |
|---|---|
| author | Banerjee, Dipanjan Ghosh, Abhik Mondal, Sushanta K. Ghosh, Parimal |
| author_facet | Banerjee, Dipanjan Ghosh, Abhik Mondal, Sushanta K. Ghosh, Parimal |
| contents | Interferometric observations of the low-frequency radio sky (< 1 GHz) are largely limited by systematic effects introduced by the ionosphere. Here, we analyse a ten-hour nighttime uGMRT Band-4 observation of 3C48 to characterise ionospheric phase fluctuations across baselines up to 25 km. We compute spatial phase structure functions across three sub-bands (575-725~MHz), revealing power-law behaviour consistent with turbulence and a diffractive scale r_diff ~ 6.7 - 8.3 km useful for assessing calibration requirements. The turbulence exhibits anisotropy with smallest scales perpendicular to Earth's magnetic field - consistent with wave-like structures such as MSTIDs rather than field-aligned irregularities. These findings from a single case study demonstrate uGMRT's sensitivity for ionospheric characterisation at low-latitudes (~ 19 deg N) and inform direction-dependent calibration strategies for similar conditions. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2507_08823 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Studying Ionospheric Phase Structure Functions Using Wide-Band uGMRT (Band-4) Interferometric Data Banerjee, Dipanjan Ghosh, Abhik Mondal, Sushanta K. Ghosh, Parimal Space Physics Earth and Planetary Astrophysics Interferometric observations of the low-frequency radio sky (< 1 GHz) are largely limited by systematic effects introduced by the ionosphere. Here, we analyse a ten-hour nighttime uGMRT Band-4 observation of 3C48 to characterise ionospheric phase fluctuations across baselines up to 25 km. We compute spatial phase structure functions across three sub-bands (575-725~MHz), revealing power-law behaviour consistent with turbulence and a diffractive scale r_diff ~ 6.7 - 8.3 km useful for assessing calibration requirements. The turbulence exhibits anisotropy with smallest scales perpendicular to Earth's magnetic field - consistent with wave-like structures such as MSTIDs rather than field-aligned irregularities. These findings from a single case study demonstrate uGMRT's sensitivity for ionospheric characterisation at low-latitudes (~ 19 deg N) and inform direction-dependent calibration strategies for similar conditions. |
| title | Studying Ionospheric Phase Structure Functions Using Wide-Band uGMRT (Band-4) Interferometric Data |
| topic | Space Physics Earth and Planetary Astrophysics |
| url | https://arxiv.org/abs/2507.08823 |