G. A. Hajj

7.9k total citations · 2 hit papers
76 papers, 5.7k citations indexed

About

G. A. Hajj is a scholar working on Astronomy and Astrophysics, Aerospace Engineering and Oceanography. According to data from OpenAlex, G. A. Hajj has authored 76 papers receiving a total of 5.7k indexed citations (citations by other indexed papers that have themselves been cited), including 56 papers in Astronomy and Astrophysics, 56 papers in Aerospace Engineering and 47 papers in Oceanography. Recurrent topics in G. A. Hajj's work include GNSS positioning and interference (55 papers), Ionosphere and magnetosphere dynamics (54 papers) and Geophysics and Gravity Measurements (43 papers). G. A. Hajj is often cited by papers focused on GNSS positioning and interference (55 papers), Ionosphere and magnetosphere dynamics (54 papers) and Geophysics and Gravity Measurements (43 papers). G. A. Hajj collaborates with scholars based in United States, United Kingdom and Germany. G. A. Hajj's co-authors include E. R. Kursinski, L.J. Romans, Kenneth R. Hardy, J. T. Schofield, R. P. Linfield, Willy Bertiger, S. S. Leroy, A. J. Mannucci, Cinzia Zuffada and C. O. Ao and has published in prestigious journals such as Science, Journal of Geophysical Research Atmospheres and Geophysical Research Letters.

In The Last Decade

G. A. Hajj

73 papers receiving 5.4k citations

Hit Papers

align trajectories sort by overperformance

What are hit papers?

Hit papers significantly outperform the citation benchmark for their cohort. A paper qualifies if it has ≥500 total citations, achieves ≥1.5× the top-1% citation threshold for papers in the same subfield and year (this is the minimum needed to enter the top 1%, not the average within it), or reaches the top citation threshold in at least one of its specific research topics.

Observing Earth's atmosphere with radio occultation measurements using the Global Positioning System

1997 1.0k citations E. R. Kursinski, G. A. Hajj et al. Journal of Geophysical Research Atmospheres profile →
Effects of antenna orientation on GPS carrier phase

1993 520 citations G. A. Hajj, Willy Bertiger et al. profile →

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name	h						Papers	Cites
G. A. Hajj United States	31	4.2k	3.4k	2.5k	2.0k	806	76	5.7k
Christian Rocken United States	37	6.4k 1.5×	6.1k 1.8×	5.2k 2.1×	2.2k 1.1×	920 1.1×	95	8.7k
Sergey Sokolovskiy United States	33	3.8k 0.9×	2.4k 0.7×	1.7k 0.7×	2.0k 1.0×	850 1.1×	72	4.6k
S. Fukao Japan	46	5.1k 1.2×	1.9k 0.5×	1.1k 0.4×	2.4k 1.2×	824 1.0×	230	6.1k
M. Yamamoto Japan	52	7.2k 1.7×	3.0k 0.9×	1.2k 0.5×	2.4k 1.2×	732 0.9×	319	8.4k
A. J. Mannucci United States	49	8.0k 1.9×	4.2k 1.2×	2.1k 0.8×	1.5k 0.7×	620 0.8×	224	9.4k
Shoichiro Fukao Japan	40	4.1k 1.0×	1.5k 0.4×	1.0k 0.4×	3.0k 1.5×	1.4k 1.7×	189	5.8k
R. F. Woodman Peru	47	7.9k 1.9×	2.8k 0.8×	1.2k 0.5×	2.1k 1.0×	481 0.6×	144	8.7k
J. Röttger Germany	34	3.4k 0.8×	806 0.2×	792 0.3×	2.0k 1.0×	566 0.7×	190	4.0k
W. K. Hocking Canada	47	5.4k 1.3×	729 0.2×	1.2k 0.5×	3.8k 1.9×	1.3k 1.6×	179	6.5k
E. R. Kursinski United States	26	3.1k 0.7×	1.8k 0.5×	1.5k 0.6×	2.1k 1.0×	1.0k 1.3×	73	4.0k

Countries citing papers authored by G. A. Hajj

Since Specialization

Citations

This map shows the geographic impact of G. A. Hajj's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by G. A. Hajj with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites G. A. Hajj more than expected).

Fields of papers citing papers by G. A. Hajj

Since Specialization

Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by G. A. Hajj. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by G. A. Hajj. The network helps show where G. A. Hajj may publish in the future.

Co-authorship network of co-authors of G. A. Hajj

This figure shows the co-authorship network connecting the top 25 collaborators of G. A. Hajj. A scholar is included among the top collaborators of G. A. Hajj based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with G. A. Hajj. G. A. Hajj is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

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20 of 20 papers shown

Chan, S., et al.. (2024). Reservoir Water Level Monitoring Using CYGNSS's Level-1 Observations. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. 17. 9090–9098. 2 indexed citations

Shah, Rashmi & G. A. Hajj. (2015). Assessment of GPS Reflectometry from TechDemoSat-1 for Scatterometry and Altimetry Applications. 2015 AGU Fall Meeting. 2015. 4 indexed citations

Pi, Xiaoqing, C. D. Edwards, G. A. Hajj, et al.. (2008). A Chapman-Layers Ionspheric Model for Mars. NASA STI/Recon Technical Report N. 8. 32557. 2 indexed citations

Edwards, C. D., C. O. Ao, S. W. Asmar, et al.. (2007). An Assessment of the Scientific Potential and Operational Feasibility of Mars Crosslink Radio Science Observations. 1353. 3259. 3 indexed citations

Ao, C. O., G. A. Hajj, B. A. Iijima, A. J. Mannucci, & T. K. Meehan. (2006). Evaluation of Moisture Retrievals Based on Open-Loop Radio Occultation Data from COSMIC and SAC-C. AGU Fall Meeting Abstracts. 2006. 1 indexed citations

Wu, Dong L., C. O. Ao, G. A. Hajj, Manuel de la Torre Juárez, & A. J. Mannucci. (2005). Sporadic E morphology from GPS‐CHAMP radio occultation. Journal of Geophysical Research Atmospheres. 110(A1). 174 indexed citations

Tsai, H. F., Toshitaka Tsuda, G. A. Hajj, Jens Wickert, & Yuichi Aoyama. (2004). Equatorial Kelvin Waves Observed with GPS Occultation Measurements (CHAMP and SAC-C). Journal of the Meteorological Society of Japan Ser II. 82(1B). 397–406. 24 indexed citations

Torre, A. de la, Toshitaka Tsuda, G. A. Hajj, & Jens Wickert. (2004). A Global Distribution of the Stratospheric Gravity Wave Activity from GPS Occultation Profiles with SAC-C and CHAMP. Journal of the Meteorological Society of Japan Ser II. 82(1B). 407–417. 22 indexed citations

Pi, Xiaoqing, G. A. Hajj, Brian Wilson, et al.. (2004). 3-Dimensional Assimilative Ionospheric Modeling for Regions of Large TEC Gradient. 753–760. 4 indexed citations

10.

Mandrake, Lukas, et al.. (2004). USC/JPL GAIM: A Real-Time Global Ionospheric Data Assimilation Model. AGU Fall Meeting Abstracts. 2004. 1 indexed citations

11.

Cardellach, Estel, C. O. Ao, Manuel de la Torre Juárez, & G. A. Hajj. (2004). Carrier phase delay altimetry with GPS‐reflection/occultation interferometry from low Earth orbiters. Geophysical Research Letters. 31(10). 67 indexed citations

12.

Hajj, G. A., C. O. Ao, B. A. Iijima, et al.. (2004). CHAMP and SAC‐C atmospheric occultation results and intercomparisons. Journal of Geophysical Research Atmospheres. 109(D6). 281 indexed citations

13.

Hajj, G. A., et al.. (2002). Analysis of CHAMP ionospheric measurements using a global ionospheric data assimilation model. NASA Technical Reports Server (NASA). 1 indexed citations

14.

Juárez, Manuel de la Torre, et al.. (2001). Single Frequency Processing of GPS Radiooccultations. AGU Spring Meeting Abstracts. 2001. 1 indexed citations

15.

Zuffada, Cinzia, G. A. Hajj, & E. R. Kursinski. (1999). A novel approach to atmospheric profiling with a mountain‐based or airborne GPS receiver. Journal of Geophysical Research Atmospheres. 104(D20). 24435–24447. 38 indexed citations

16.

Hajj, G. A., et al.. (1995). Sensing the Atmosphere From a Low-Earth Orbiter Tracking GPS: Early Results and Lessons From the GPS/MET Experiment. 1167–1174. 5 indexed citations

17.

Hardy, Kenneth R., G. A. Hajj, & E. R. Kursinski. (1994). Accuracies of atmospheric profiles obtained from GPS occultations. International Journal of Satellite Communications. 12(5). 463–473. 47 indexed citations

18.

Hardy, Kenneth R., G. A. Hajj, E. R. Kursinski, & R. Ibañez‐Meier. (1993). Accuracies of Atmospheric Profiles Obtained from GPS Occultations. 1545–1556. 12 indexed citations

19.

Hajj, G. A., R. Ibañez‐Meier, & E. R. Kursinski. (1993). Ionospheric Imaging from a Low Earth Orbiter Tracking GPS. 1315–1322. 1 indexed citations

20.

Bassiri, S. & G. A. Hajj. (1993). Higher-Order Ionospheric Effects on the GPS Observables and Means of Modeling Them. NASA Technical Reports Server (NASA). 82. 1071–1086. 18 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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