Development and application of GNSS remote sensing techniques for Earth Observation

• Applicant: Professor Dr.-Ing. Harald Schuh
• Subject Area: Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography ; Atmospheric Science
• Term: from 2017 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 387726247

• Final Report Year: 2024

Final Report Abstract

The goal of the project was to improve our understanding of the ionospheric scintillations that cause disruption of trans-ionospheric radio signals. In general, various ionospheric phenomena were investigated and their related effects were studied, which were useful in realizing the objectives of the project. The F-region scintillations were studied first using the GPS ground measurements with alternative method of using high-rate receivers to directly output the S4 index, in addition to the method of using standard GNSS dual-frequency receivers. From these methods, ionospheric irregularities were studied using temporal as well as spatial distribution. Further, a prominent feature of Equatorial Ionization Anomaly was studied using the equatorial GPS stations and high correlations were observed between VTEC and solar indices. In addition, MSTIDs were, for first the time, reported using GPS receiver networks of Northern Africa during 2008-2016. The continuous long time series of GPS measurements provided crucial information about the occurrence of MSTIDs, especially due to the atmospheric gravity waves from the convection zone. Moreover, this MSTIDs can be a source for the excitation of equatorial night time irregularities, which are widely known as EPBs. The study was further extended to the space-based measurements that relied on the GPS radio occultation technique from the FormoSat-3/COSMIC mission. About 5 million global profiles of high vertical resolution were analyzed and occurrence climatology was established, which were crucial in understanding the characteristics of the EPBs. The occurrence of EPBs was analyzed based on the altitudinal information and it was observed that a larger altitudinal extent was covered by the EPBs during the high solar active years than the low solar active years. Furthermore, a genesis study was investigated related to the occurrence as well as uplift of the EPBs. It was found that, in general, the occurrence of EPBs was mainly governed by the peak PRE values during the sunset time through complex electrodynamic process. It was for the first time observed that the atmospheric gravity waves which could be generated in troposphere were crucial in influencing in the EPB heights during the low solar activity, in particular. Research within this project will also have an impact on future satellite missions that will bring new opportunities, enhanced data densities and higher data rates and thus will improve detection accuracy. A combination of different datasets with the ground-based measurements from GNSS and satellite altimetry will provide additional inputs for deriving a long-term comprehensive perspective of such irregularities.

Publications

• Correlation between amplitude scintillation and the TEC fluctuation over the South East Asian region during the Solar cycle 24. Specialized Summit on Space Geodesy and Ionosphere Research (SGI), Berlin, Germany, June
  Nguyen, C.T.; Alizadeh, M. & Schuh, H.
  
• Global morphology of ionospheric sporadic E layer from the FormoSat-3/COSMIC GPS radio occultation experiment. GPS Solutions, 22(4).
  Tsai, Lung-Chih; Su, Shin-Yi; Liu, Chao-Han; Schuh, Harald; Wickert, Jens & Alizadeh, Mohamad Mahdi
  
• Ionospheric scintillation detection over Iran, based on GPS observations. Journal of Geospatial Information Technology, 6(3), 187-197.
  Sobhkhiz, Sahar & Alizadeh, Mohammad Mehdi
  
• Irregularities in Electron density above Mesoscale thunderstorms using Global Navigation Satellite Systems Measurements, Oral presentation: 7th Workshop on Vertical Coupling in the Atmosphere-Ionosphere System, 2-6 July, Potsdam – Germany.
  Alizadeh M.M. & Rahmani Y.
  
• Occurrence characteristics of ionospheric scintillation over the South East Asian region during the Solar cycle 24. EGU General Assembly, Vienna, Austria, April.
  Nguyen, C.T.; Oluwadare, S.T.; Alizadeh, M. & Schuh, H.
  
• Characterization of GPS-TEC over African equatorial ionization anomaly (EIA) region during 2009–2016. Advances in Space Research, 63(1), 282-301.
  Oluwadare, Temitope Seun; Nguyen, Thai Chinh; Akala, Andrew Oke-Ovie; Heise, Stefan; Alizadeh, Mahdi & Schuh, Harald
  
• Combining ground and space-based geodetic measurements for multidimensional modeling of the ionosphere. Oral presentation: International Workshop on GNSS Ionosphere, 25-26 September, DLR Neustrelitz, Germany.
  Alizadeh M.M. & Schuh H.
  
• Combining Neural Network with Genetic Algorithm for prediction of S4 Parameter using GPS measurement. Journal of Geospatial Information Technology, 7(3), 57-77.
  Atabati, Ali Reza & Alizadeh, Mohammad Mahdi
  
• Combining space geodetic techniques for global multi-dimensional modeling of the ionosphere. Poster presentation: IUGG General Assembly 2019, July, Montreal, Canada.
  Alizadeh M.M. & Schuh H.
  
• Comparative studies of Traveling Ionospheric Disturbances (TID) at North, South and Equatorial African Continent. European Geosciences Union General Assembly (EGU), Vienna, Austria, April.
  Oluwadare, S.T.; Nguyen, C.T; Alizadeh, M. & Schuh, H.
  
• Global distribution of Equatorial Ionization Anomaly (EIA) crests during solar cycle 24. IUGG, Symposium: JG05 - Remote Sensing and Modelling of the Atmosphere (IAG, IAGA, IAMAS, IAVCEI), Montreal, Canada, July.
  Nguyen, C.T.; Le, N.T.; Oluwadare, S.T.; Alizadeh, M. & Schuh, H.
  
• Global distribution of Equatorial Ionization Anomaly (EIA) crests during solar cycle 24. Specialized Summit on Space Geodesy and Ionosphere Research (SGI), Berlin, Germany, September
  Nguyen, C.T.; Oluwadare, S.T.; Alizadeh, M.; Tsai, L.C. & Schuh, H.
  
• Global occurrence characteristic of plasma bubbles during high and low solar active years using GPS-RO based measurements from FormoSat-3/COSMIC . International Reference Ionosphere 2019 Workshop, Nicosia, Cyprus, September
  Kepkar, A., Arras, C., Wickert, J., Schuh, H. & Alizadeh, M.
  
• Global perspective on the occurrence of plasma bubbles using GPS-RO based measurements from FormoSat-3/COSMIC - Abstracts, 27th IUGG General Assembly, Montréal, Canada, July.
  Kepkar, A., Arras, C., Wickert, J., Schuh, H. & Alizadeh, M.
  
• Predicting Ionospheric Scintillation by S4 and ROTI Parameters Using Combination of Neural Network and Genetic Algorithm, Poster presentation: IUGG General Assembly 2019, July, Montreal, Canada.
  Atabati A., Alizadeh M.M. & Schuh H.
  
• Statistical study of Medium-Scale Traveling Ionmospheric Disturbances (MSTIDs) characteristics with GPS network over North African region. International Union of Geodesy and Geophysics (IUGG), Symposium: JG05 - Remote Sensing and Modelling of the Atmosphere (IAG, IAGA, IAMAS, IAVCEI), Montreal, Canada, July.
  Oluwadare, S.T.; Jakowski, N.; Cesar, E.V.; Alizadeh, M. & Schuh, H.
  
• Comparison study of equatorial F-region irregularities using GPS based SPACE and GROUND measurements . Frontiers of Geodetic Science. Stuttgart, Germany, September
  Kepkar, A., Arras, C., Wickert, J., Schuh, H. & Alizadeh, M.
  
• Investigation of Regional Ionospheric Irregularities Over Africa (IRIA). German Aerospace Center (DLR), Neustrelitz, June
  Oluwadare, S.T.; Jakowski, N.; Cesar, E.V.; Alizadeh, M. & Schuh, H.
  
• Occurrence climatology of equatorial plasma bubbles derived using FormoSat-3 ∕ COSMIC GPS radio occultation data. Annales Geophysicae, 38(3), 611-623.
  Kepkar, Ankur; Arras, Christina; Wickert, Jens; Schuh, Harald; Alizadeh, Mahdi & Tsai, Lung-Chih
  
• Probing vertical coupling effects of thunderstorms on lower ionosphere using GNSS data. Advances in Space Research, 66(8), 1967-1976.
  Rahmani, Yaser; Alizadeh, M. Mahdi; Schuh, Harald; Wickert, Jens & Tsai, Lung-Chih
  
• Remote sensing ionospheric variations due to total solar eclipse, using GNSS observations. Geodesy and Geodynamics, 11(3), 202-210.
  Alizadeh, Mohamad Mahdi; Schuh, Harald; Zare, Saeed; Sobhkhiz-Miandehi, Sahar & Tsai, Lung-Chih
  
• Coastal sea-surface wave measurements using software-based GPS reflectometers in Lanyu, Taiwan. GPS Solutions, 25(4).
  Tsai, Lung-Chih; Su, Shin-Yi; Chien, Hwa; Liu, Chao-Han; Schuh, Harald; Wickert, Jens & Alizadeh, Mohamad Mahdi
  
• Diagnostics of Es Layer Scintillation Observations Using FS3/COSMIC Data: Dependence on Sampling Spatial Scale. Remote Sensing, 13(18), 3732.
  Tsai, Lung-Chih; Su, Shin-Yi; Liu, Chao-Han; Schuh, Harald; Wickert, Jens & Alizadeh, Mohamad Mahdi
  
• Investigation of equatorial F-region scintillations using GPS radio occultation based on FormoSat-3/COSMIC mission. ATMOchange PhD Days 2021 Karlsruhe, Germany, September
  Kepkar, A., Arras, C., Wickert, J., Schuh, H. & Alizadeh, M.
  
• Investigation of space weather phenomenon using GPS radio occultation based on FormoSat-3/COSMIC mission. Frontiers of Geodetic Science. Hannover, Germany, September
  Kepkar, A., Arras, C., Wickert, J., Schuh, H. & Alizadeh, M.
  
• Ionospheric Scintillation Prediction on S4 and ROTI Parameters Using Artificial Neural Network and Genetic Algorithm. Remote Sensing, 13(11), 2092.
  Atabati, Alireza; Alizadeh, Mahdi; Schuh, Harald & Tsai, Lung-Chih
  
• Long term study of equatorial plasma bubbles using GPS based space measurements. Joint Scientific Assembly IAGA-IASPEI 2021. Hyderabad, India, September
  Kepkar, A., Arras, C., Wickert, J., Schuh, H., Alizadeh, M. & Tsai, L.-C.
  
• On the first simultaneous and conjugate MSTIDs observation over the African sector. Frontiers of Geodetic Science (FROG), Germany, September
  Oluwadare, S.T.; Alizadeh, M. & Schuh, H.
  
• Selection of the optimal machine learning algorithms for space weather prediction. Frontiers of Geodetic Science. Hannover, Germany, September
  Nguyen, C.T.; Le, N.T.; Oluwadare, S.T.; Schmidt, T.; Wickert, J. & Schuh, H.
  
• Spatial and Temporal Distributions of Ionospheric Irregularities Derived from Regional and Global ROTI Maps. Remote Sensing, 14(1), 10.
  Nguyen, Chinh Thai; Oluwadare, Seun Temitope; Le, Nhung Thi; Alizadeh, Mahdi; Wickert, Jens & Schuh, Harald
  
• Detecting Tsunami originated gravity waves using GNSS remote sensing, 8th Workshop on Vertical coupling in the Atmosphere-Ionosphere System. Online presentation, Sopron, Hungary, 11-15 July
  Alizadeh M.M., Foroodi Z., Schuh H. & Tsai L.C.
  
• Natural hazard effects on ionospheric parameters detected by various space geodetic techniques, 2nd Symposium of IAG Commission 4 “Positioning and Applications”. Oral presentation, Potsdam Germany, September
  Alizadeh M.M., Foroodi Z., Rahmani Y., Schuh H. & Tsai L.C.
  
• Prediction of Ionospheric Irregularities using Combination of Machine Learning Algorithms, 2nd Symposium of IAG Commission 4 “Positioning and Applications”, Potsdam Germany, September
  Atabati A., Alizadeh M.M., Jazireeyan I. & Schuh H.