Svein-Erik Hamran

• Stack, K.M.; Ives, L.R.W.; Gupta, S.; Lamb, M.P.; Tebolt, M. & Caravaca, G. [Show all 42 contributors for this article] (2024). Sedimentology and Stratigraphy of the Shenandoah Formation, Western Fan, Jezero Crater, Mars. Journal of Geophysical Research (JGR): Planets. ISSN 2169-9097. 129(2). doi: 10.1029/2023JE008187.
• Paige, David A.; Hamran, Svein-Erik; Amundsen, Hans E. Foss; Berger, Tor; Russell, Patrick & Kakaria, Reva [Show all 15 contributors for this article] (2024). Ground penetrating radar observations of the contact between the western delta and the crater floor of Jezero crater, Mars. Science Advances. ISSN 2375-2548. 10(4). doi: 10.1126/sciadv.adi8339.
• Ölçek, Deniz; Al Jebali, Ramsey; Meier, Dirk; Haavik, Andreas Fagerland; Gheorghe, Codin & Gjennestad, Magne Sødal [Show all 8 contributors for this article] (2024). Development of a compact scintillator-based gamma-ray neutron detector for terrestrial and space applications. Journal of Instrumentation (JINST). ISSN 1748-0221. 19. doi: 10.1088/1748-0221/19/01/C01030.
• Crumpler, L.S.; Horgan, B.H.N.; Simon, J.I.; Stack, K.M.; Alwmark, S. & Dromart, G. [Show all 23 contributors for this article] (2023). In Situ Geologic Context Mapping Transect on the Floor of Jezero Crater From Mars 2020 Perseverance Rover Observations. Journal of Geophysical Research (JGR): Planets. ISSN 2169-9097. 128(10). doi: 10.1029/2022JE007444. Full text in Research Archive
• Simon, J.I.; Hickman-Lewis, K.; Cohen, B.A.; Mayhew, L.E.; Shuster, D.L. & Debaille, V. [Show all 67 contributors for this article] (2023). Samples Collected From the Floor of Jezero Crater With the Mars 2020 Perseverance Rover. Journal of Geophysical Research (JGR): Planets. ISSN 2169-9097. 128(6). doi: 10.1029/2022JE007474. Full text in Research Archive
• Horgan, Briony; Udry, Arya; Rice, Melissa; Alwmark, Sanna; Amundsen, Hans E. Foss & Bell, James F. [Show all 43 contributors for this article] (2023). Mineralogy, Morphology, and Emplacement History of the Maaz Formation on the Jezero Crater Floor From Orbital and Rover Observations. Journal of Geophysical Research (JGR): Planets. ISSN 2169-9097. 128(8). doi: 10.1029/2022JE007612. Full text in Research Archive
• Casademont, Titus; Eide, Sigurd; Shoemaker, E.S.; Liu, Y.; Nunes, D.C. & Russell, P. [Show all 8 contributors for this article] (2023). RIMFAX Ground Penetrating Radar Reveals Dielectric Permittivity and Rock Density of Shallow Martian Subsurface. Journal of Geophysical Research (JGR): Planets. ISSN 2169-9097. 128(5). doi: 10.1029/2022JE007598. Full text in Research Archive
• Eide, Sigurd; Casademont, Titus; Berger, Tor; Dypvik, Henning; Hamran, Svein-Erik & Shoemaker, Emileigh S. (2023). Radar Attenuation in the Shallow Martian Subsurface: RIMFAX Time-Frequency Analysis and Constant-Q Characterization Over Jezero Crater Floor. Geophysical Research Letters. ISSN 0094-8276. 50(7). doi: 10.1029/2022GL101429. Full text in Research Archive
• Farley, K.A.; Stack, K.M.; Shuster, D.L.; Horgan, B.H.N.; Hurowitz, J.A. & Tarnas, J.D. [Show all 113 contributors for this article] (2022). Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars. Science. ISSN 0036-8075. 377(6614). doi: 10.1126/science.abo2196.
• Hamran, Svein-Erik; Paige, David A.; Allwood, Abigail; Amundsen, Hans E. Foss; Berger, Tor & Brovoll, Sverre [Show all 16 contributors for this article] (2022). Ground penetrating radar observations of subsurface structures in the floor of Jezero crater, Mars. Science Advances. ISSN 2375-2548. 8(34). doi: 10.1126/sciadv.abp8564.
• Eide, Sigurd; Casademont, Titus; Aardal, Øyvind Lund & Hamran, Svein-Erik (2022). Modeling FMCW Radar for Subsurface Analysis. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. ISSN 1939-1404. 15, p. 2998–3007. doi: 10.1109/JSTARS.2022.3165135. Full text in Research Archive Show summary

  Determining subsurface properties through ground penetrating radar sounding can be challenging, especially in planetary exploration, where little is known about the terrain and additional observations are limited. Analysis and interpretation of data acquired with the Radar Imager for Mars’ Subsurface Experiment (RIMFAX) could therefore be improved by in-detail comparison with forward modeling. RIMFAX transmits a frequency modulated continuous waveform and utilizes a stretch processing receiver, and we demonstrate how accurate modeling can be achieved through finite-difference time-domain simulations. As the simulation scheme do not allow for direct implementation of such radar system, this study presents the necessary steps in order to replicate the same transmitter and receiver characteristics. In particular, we investigate how the method holds for modeling sounding in a realistic subsurface medium with attenuating and dispersive properties, by comparing the results with analytical estimates. The modeling approach is also assessed through comparison with RIMFAX field test measurements.

• Eide, Sigurd; Hamran, Svein-Erik; Dypvik, Henning & Amundsen, Hans E. F. (2021). Ground-Penetrating Radar Modeling across the Jezero Crater Floor. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. ISSN 1939-1404. 14, p. 2484–2493. doi: 10.1109/JSTARS.2021.3055944. Full text in Research Archive
• Farley, Kenneth A.; Williford, Kenneth H.; Stack, Kathryn M.; Bhartia, Rohit; Chen, Al & de la Torre, Manuel [Show all 29 contributors for this article] (2020). Mars 2020 mission overview. Space Science Reviews. ISSN 0038-6308. 216:142(8), p. 1–41. doi: 10.1007/s11214-020-00762-y.
• Stack, Kathryn M.; Williams, Nathan R; Calef III, Fred; Sun, Vivian Z; Williford, Kenneth H & Farley, Kenneth A. [Show all 65 contributors for this article] (2020). Photogeologic Map of the Perseverance Rover Field Site in Jezero Crater Constructed by the Mars 2020 Science Team. Space Science Reviews. ISSN 0038-6308. 216. doi: 10.1007/s11214-020-00739-x.
• Hamran, Svein-Erik; Paige, David A.; Amundsen, Hans E. Foss; Berger, Tor; Brovoll, Sverre & Carter, Lynn [Show all 14 contributors for this article] (2020). Radar imager for Mars’ subsurface experiment—RIMFAX. Space Science Reviews. ISSN 0038-6308. 216(8). doi: 10.1007/s11214-020-00740-4. Full text in Research Archive
• Eriksrød, Jon Håvard; Burkhart, John; Lande, Tor Sverre & Hamran, Svein-Erik (2020). Bistatic SAR Radar for Long-Term Snow Pack Monitoring. IEEE Transactions on Geoscience and Remote Sensing. ISSN 0196-2892. 58(1), p. 218–226. doi: 10.1109/TGRS.2019.2935781.
• Gonzales, Edward; Cordoba, Elizabeth & Hamran, Svein-Erik (2017). Compatibility tests between the mars vehicle system test bed and RIMFAX radar antenna prototype for the mars 2020 mission. IEEE International Symposium on Electromagnetic Compatibility. ISSN 1077-4076. p. 44–50. doi: 10.1109/ISEMC.2017.8077839.
• Ciarletti, Valérie; Clifford, Stephen; Plettemeier, Dirk; Le Gall, Alice; Herve, Yann & Dorizon, Sophie [Show all 15 contributors for this article] (2017). The WISDOM Radar: Unveiling the Subsurface Beneath the ExoMars Rover and Identifying the Best Locations for Drilling. Astrobiology. ISSN 1531-1074. 17(6-7), p. 565–584. doi: 10.1089/ast.2016.1532.
• Aardal, Øyvind; Brovoll, Sverre; Berger, Tor; Balasingham, Ilangko & Hamran, Svein-Erik (2017). Phase distortions in radar respiration monitoring, 2017 First IEEE MTT-S International Microwave Bio Conference (IMBIOC). IEEE (Institute of Electrical and Electronics Engineers). ISSN 978-1-5386-1713-7. doi: 10.1109/IMBIOC.2017.7965778.
• Bjørndal, Øystein; Hamran, Svein-Erik & Lande, Tor Sverre (2017). Bitstream radar waveforms for generic single-chip radar. International Journal of Microwave and Wireless Technologies (IJMWT). ISSN 1759-0787. 9(6), p. 1325–1337. doi: 10.1017/S1759078717000782.
• Bjørndal, Øystein; Hamran, Svein-Erik & Lande, Tor Sverre (2016). Square wave architectures for radar-on-chip. In Gibson, Andrew (Eds.), 2016 46th European Microwave Conference (EuMC). IEEE (Institute of Electrical and Electronics Engineers). ISSN 978-2-87487-043-9. p. 1485–1488. doi: 10.1109/EuMC.2016.7824636.
• García-Pardo, Concepción; Chavez-Santiago, Raul; Fornes-Leal, Alejandro; Brovoll, Sverre; Aardal, Øyvind & Bergsland, Jacob [Show all 8 contributors for this article] (2016). Experimental Ultra Wideband Path Loss Models for Implant Communications, 2016 IEEE 27th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 4-8 September 2016. IEEE (Institute of Electrical and Electronics Engineers). ISSN 978-1-5090-3254-9. doi: 10.1109/PIMRC.2016.7794780.
• Aardal, Øyvind; Brovoll, Sverre; Paichard, Yoann; Berger, Tor; Lande, Tor Sverre & Hamran, Svein-Erik (2015). Radar sensitivity to human heartbeats and respiration. Proceedings of SPIE, the International Society for Optical Engineering. ISSN 0277-786X. 9461. doi: 10.1117/12.2180924.
• (2015). Harmonic Synthetic Aperture Radar Processing. IEEE Geoscience and Remote Sensing Letters. ISSN 1545-598X. 12(10), p. 2066–2069. doi: 10.1109/LGRS.2015.2447517.
• Bjørndal, Øystein; Hamran, Svein-Erik & Lande, Tor Sverre (2015). UWB waveform generator for digital CMOS radar. In Almeida, Teresa Mendes de (Eds.), Circuits and Systems (ISCAS), 2015 IEEE International Symposium on. IEEE conference proceedings. ISSN 978-1-4799-8391-9. p. 1510–1513. doi: 10.1109/ISCAS.2015.7168932.
• Solberg, Lars Erik; Aardal, Øyvind; Berger, Tor; Balasingham, Ilangko; Fosse, Erik & Hamran, Svein-Erik (2015). Experimental investigation into radar-based central blood pressure estimation. IET Radar, Sonar & Navigation. ISSN 1751-8784. 9(2), p. 145–153. doi: 10.1049/iet-rsn.2014.0206. Full text in Research Archive
• Floor, Pål Anders; Chavez-Santiago, Raul; Brovoll, Sverre; Aardal, Øyvind; Bergsland, Jacob & Grymyr, Ole-Johannes [Show all 10 contributors for this article] (2015). In-body to on-body Ultrawideband propagation model derived from measurements in living animals. IEEE journal of biomedical and health informatics. ISSN 2168-2194. 19(3), p. 938–948. doi: 10.1109/JBHI.2015.2417805. Full text in Research Archive Show summary

  Ultra wideband (UWB) radio technology for wireless implants has gained significant attention. UWB enables the fabrication of faster and smaller transceivers with ultra low power consumption, which may be integrated into more sophisticated implantable biomedical sensors and actuators. Nevertheless, the large path loss suffered by UWB signals propagating through inhomogeneous layers of biological tissues is a major hindering factor. For the optimal design of implantable transceivers, the accurate characterization of the UWB radio propagation in living biological tissues is indispensable. Channel measurements in phantoms and numerical simulations with digital anatomical models provide good initial insight into the expected path loss in complex propagation media like the human body, but they often fail to capture the effects of blood circulation, respiration, and temperature gradients of a living subject. Therefore, we performed UWB channel measurements within 1-6 GHz on two living porcine subjects because of the anatomical resemblance with an average human torso. We present for the first time a path loss model derived from these invivo measurements, which includes the frequency-dependent attenuation. The use of multiple on-body receiving antennas to combat the high propagation losses in implant radio channels was also investigated.

• Langley, Kirsty A; Kohler, Jack; Sinisalo, Anna Katariina; Øyan, Mats Jørgen; Hamran, Svein-Erik & Hattermann, Tore [Show all 8 contributors for this article] (2014). Low melt rates with seasonal variability at the base of Fimbul Ice Shelf, East Antarctica, revealed by in situ interferometric radar measurements. Geophysical Research Letters. ISSN 0094-8276. 41(22), p. 8138–8146. doi: 10.1002/2014GL061782.
• Brovoll, Sverre; Berger, Tor; Paichard, Yoann; Aardal, Øyvind; Lande, Tor Sverre & Hamran, Svein-Erik (2014). Time-lapse imaging of human heart motion with switched array UWB radar. IEEE Transactions on Biomedical Circuits and Systems. ISSN 1932-4545. 8(5), p. 704–715. doi: 10.1109/TBCAS.2014.2359995.
• Øyan, Mats Jørgen; Hamran, Svein-Erik; Damsgård, Leif & Berger, Tor (2014). Compact airborne C-band radar sounder. IEEE Transactions on Geoscience and Remote Sensing. ISSN 0196-2892. 52(10), p. 6326–6332. doi: 10.1109/TGRS.2013.2296074.
• Aardal, Øyvind; Paichard, Yoann; Brovoll, Sverre; Berger, Tor; Lande, Tor Sverre & Hamran, Svein-Erik (2013). Physical Working Principles of Medical Radar. IEEE Transactions on Biomedical Engineering. ISSN 0018-9294. 60(4), p. 1142–1149. doi: 10.1109/TBME.2012.2228263.
• Sinisalo, Anna Katariina; Anschütz, Helgard; Aasen, Anne Tårånd; Langley, Kirsty A; Deschwanden, Angela von & Kohler, Jack [Show all 12 contributors for this article] (2013). Surface mass balance on Fimbul ice shelf, East Antarctica: Comparison of field measurements and large-scale studies. Journal of Geophysical Research (JGR): Atmospheres. ISSN 2169-897X. 118(20), p. 11625–11635. doi: 10.1002/jgrd.50875.
• (2012). Experiments with autofocus for strip map synthetic aperture radar data. IEEE International Conference on Radar (RADAR). ISSN 1097-5764. doi: 10.1109/RADAR.2012.6212108.
• Vu, Tuan Anh; Sudalaiyandi, Shanthi; Hjortland, Håkon André; Næss, Øivind; Lande, Tor Sverre & Hamran, Svein-Erik (2012). A Variable-Gain Single-Bit Ultra-Wideband Quantizer for Baseband Receiver Front-End. In Wang, C (Eds.), 2012 IEEE Asia Pacific Conference on Circuits and Systems. IEEE conference proceedings. ISSN 978-1-4577-1728-4. p. 483–486. doi: 10.1109/apccas.2012.6419077.
• Øyan, Mats Jørgen; Hamran, Svein-Erik; Hanssen, Leif; Berger, Tor & Plettemeier, Dirk (2012). Ultrawideband Gated Step Frequency Ground-Penetrating Radar. IEEE Transactions on Geoscience and Remote Sensing. ISSN 0196-2892. 50(1), p. 212–220. doi: 10.1109/TGRS.2011.2160069.
• Lecomte, Isabelle; Juliussen, Håvard; Støren, Eivind Wilhelm Nagel; Sauvin, Guillaume Cédric; Hamran, Svein-Erik & Lavrientiev, Ivan [Show all 8 contributors for this article] (2012). Geophysical Investigations of Unstable Mountain Slopes in Jotunheimen, Norway. In Several, Authors (Eds.), Near Surface Geoscience 2012. European Association of Geoscientists and Engineers (EAGE). ISSN 978-90-73834-34-7. doi: 10.3997/2214-4609.20143461.
• Aardal, Øyvind; Hamran, Svein-Erik; Berger, Tor; Paichard, Yoann & Lande, Tor Sverre (2011). Chest movement estimation from radar modulation caused by heartbeats. In Cauwenberghs, G. (Eds.), IEEE Biomedical Circuits and Systems Conference 2011. IEEE conference proceedings. ISSN 978-1-4577-1469-6. p. 422–425. doi: 10.1109/biocas.2011.6107825.
• Müller, Karsten; Hamran, Svein-Erik; Sinisalo, Anna Katariina & Hagen, Jon Ove Methlie (2011). Phase Center of L-Band Radar in Polar Snow and Ice. IEEE Transactions on Geoscience and Remote Sensing. ISSN 0196-2892. 49(11), p. 4572–4579. doi: 10.1109/TGRS.2011.2140376.
• Vu, Tuan Anh; Sudalaiyandi, Shanthi; Hjortland, Håkon André; Næss, Øivind; Lande, Tor Sverre & Hamran, Svein-Erik (2011). An Ultra-Wideband, Continuous-Time, Differential, Single-Bit Quantizer in 90 nm CMOS. The Midwest Symposium on Circuits and Systems conference proceedings. ISSN 1548-3746. doi: 10.1109/MWSCAS.2011.6026680.
• Vu, Tuan Anh; Sudalaiyandi, Shanthi; Hjortland, Håkon André; Næss, Øivind; Lande, Tor Sverre & Hamran, Svein-Erik (2011). A 70-dB, 3.1-10.6-GHz CMOS Amplifier in Low-Power 90 nm CMOS. The Midwest Symposium on Circuits and Systems conference proceedings. ISSN 1548-3746. p. 1–4. doi: 10.1109/MWSCAS.2011.6026639.
• Vu, Tuan Anh; Sudalaiyandi, Shanthi; Hjortland, Håkon André; Næss, Øivind; Lande, Tor Sverre & Hamran, Svein-Erik (2011). An ultra-wideband, continuous-time, differential, single-bit quantizer in 90 nm CMOS. In Nooshabadi, Saeid (Eds.), Circuits and Systems (MWSCAS), 2011 IEEE 54th International Midwest Symposium on. IEEE conference proceedings. ISSN 978-1-61284-856-3. p. 1–4. doi: 10.1109/mwscas.2011.6026680.
• Solberg, Lars Erik; Hamran, Svein-Erik & Balasingham, Ilangko (2011). Realistic Simulations of Aorta Radius Estimation. In Marchetti, Nicola & Frattasi, Luigi (Ed.), 4th International Symposium on Applied Sciences in Biomedical and Communication Technologies. ACM Publications. ISSN 978-1-4503-0913-4. doi: 10.1145/2093698.2093745.
• Anschütz, Helgard; Sinisalo, Anna Katariina; Isaksson, Elisabeth; McConnell, Joseph R.; Hamran, Svein-Erik & Bisiaux, M. M. [Show all 8 contributors for this article] (2011). Variation of accumulation rates over the last eight centuries on the East Antarctic Plateau derived from volcanic signals in ice cores. Journal of Geophysical Research (JGR): Atmospheres. ISSN 2169-897X. 116. doi: 10.1029/2011JD015753.
• (2011). Comparison of two methods for automatic range alignment in ISAR maging. IEEE International Conference on Radar (RADAR). ISSN 1097-5764. p. 6–11. doi: 10.1109/RADAR.2011.5960489.
• Aardal, Øyvind; Hamran, Svein-Erik; Berger, Tor; Hammerstad, Jan & Lande, Tor Sverre (2011). Radar cross section of the human heartbeat and respiration in the 500MHz to 3GHz band. In Ponchak, George E. (Eds.), Radio and Wireless Symposium (RWS), 2011 IEEE. IEEE conference proceedings. ISSN 978-1-4244-7687-9. p. 422–425. doi: 10.1109/rws.2011.5725466.
• Ciarletti, Valerie; Corbel, Charlotte; Plettemeier, Dirk; Cais, Philippe; Clifford, Stephen M. & Hamran, Svein-Erik (2011). WISDOM GPR Designed for Shallow and High-Resolution Sounding of the Martian Subsurface. Proceedings of the IEEE. ISSN 0018-9219. 99(5), p. 824–836. doi: 10.1109/JPROC.2010.2100790.
• Vu, Tuan Anh; Sudalaiyandi, Shanthi; Dooghabadi, Malihe Zarre; Hjortland, Håkon André; Næss, Øivind & Lande, Tor Sverre (2010). Continuous-Time CMOS Quantizer for Ultra-Wideband Applications. IEEE International Symposium on Circuits and Systems proceedings. ISSN 0271-4302. p. 3757–3760.
• (2010). An efficient scaled maximum likelihood algorithm for translational motion estimation in ISAR imaging. IEEE International Conference on Radar (RADAR). ISSN 1097-5764. p. 75–80.
• Tuan, Anh Vu; Sudalaiyandi, Shanthi; Dooghabadi, Malihe Zarre; Hjortland, Håkon André; Næss, Øivind & Lande, Tor Sverre (2010). Continuous-time CMOS quantizer for ultra-wideband applications. In Serdijn, Wouter A. (Eds.), Circuits and Systems (ISCAS), Proceedings of 2010 IEEE International Symposium on. IEEE conference proceedings. ISSN 978-1-4244-5308-5. p. 3757–3761.
• Sudalaiyandi, Shanthi; Dooghabadi, Malihe Zarre; Tuan, Anh Vu; Hjortland, Håkon André; Næss, Øivind & Lande, Tor Sverre (2010). Power-efficient CTBV symbol detector for UWB applications. In Hong, Wei (Eds.), Proceedings of IEEE International Conference on Ultra Wideband. IEEE conference proceedings. ISSN 978-1-4244-5305-4. p. 1–4.
• Aardal, Øyvind; Hamran, Svein-Erik; Berger, Tor; Hammerstad, Jan & Lande, Tor Sverre (2010). Radar Cross Section of the Human Heartbeat and Respiration. In Georgiou, Julius (Eds.), Proceedings of BioCAS 2010. IEEE conference proceedings. ISSN 9781424472680.
• Solberg, Lars Erik; Balasingham, Ilangko & Hamran, Svein-Erik (2010). Candidate Estimators for Aorta Diameter Estimation Using Monostatic Radar. In Leung, Victor & Vasilakos, Athanasios (Ed.), 5th International ICST Conference on Body Area Networks. The Institute for Computer Sciences, Social Informatics and Telecommunications Engineering (ICST). ISSN 978-963-9995-01-7.
• Solberg, Lars Erik; Hamran, Svein-Erik; Berger, Tor & Balasingham, Ilangko (2010). Minimum Variance Signal Selection for Aorta Radius Estimation Using Radar. EURASIP Journal on Advances in Signal Processing. ISSN 1687-6172. doi: 10.1155/2010/682037. Full text in Research Archive
• Müller, Karsten; Sinisalo, Anna Katariina; Anschütz, Helgard; Hamran, Svein-Erik; Hagen, Jon Ove Methlie & McConnell, Joseph (2010). An 860 km surface mass-balance profile on the East Antarctic plateau derived by GPR. Annals of Glaciology. ISSN 0260-3055. 51(55), p. 1–8.
• Soldovieri, F; Prisco, G & Hamran, Svein-Erik (2009). A preparatory study on subsurface exploration on Mars using GPR and microwave tomography. Planetary and Space Science. ISSN 0032-0633. 57(8-9), p. 1076–1084. doi: 10.1016/j.pss.2008.11.014.
• Solberg, Lars Erik; Balasingham, Ilangko; Hamran, Svein-Erik & Fosse, Erik (2009). A Feasibility Study on Aortic Pressure Estimation Using UWB Radar. In Beaulieu, Norman & Milstein, Laurence (Ed.), Ultra-Wideband, 2009. ICUWB 2009. IEEE International Conference on. IEEE conference proceedings. ISSN 978-1-4244-2930-1. p. 464–468.
• Vu, Anh Tuan; Dooghabadi, Malihe Zarre; Sudalaiyandi, Shanthi; Hjortland, Håkon André; Næss, Øivind & Lande, Tor Sverre (2009). UWB Vivaldi Antenna for Beamforming. In Ytterdal, Trond & Aunet, Snorre (Ed.), Proceedings of the 27th Norchip Conference, Trondheim, 16.-17. November, 2009. IEEE conference proceedings. ISSN 978-1-4244-4311-6.
• Dooghabadi, Malihe Zarre; Vu, Anh Tuan; Sudalaiyandi, Shanthi; Hjortland, Håkon André; Lande, Tor Sverre & Næss, Øivind (2009). Electromagnetic Impulse Radio Camera. In Ytterdal, Trond & Aunet, Snorre (Ed.), Proceedings of the 27th Norchip Conference, Trondheim, 16.-17. November, 2009. IEEE conference proceedings. ISSN 978-1-4244-4311-6.
• Brandt, Ola; Langley, Kirsty; Giannopoulos, Antonios; Hamran, Svein Erik & Kohler, Jack (2009). Radar Response of Firn Exposed to Seasonal Percolation, Validation Using Cores and FDTD Modeling. IEEE Transactions on Geoscience and Remote Sensing. ISSN 0196-2892. 47(8), p. 2773–2786. doi: 10.1109/TGRS.2009.2016555. Show summary

  We use ground-penetrating radars (GPRs), firn cores, and electromagnetic finite-difference time-domain (FDTD) numerical modeling to characterize the GPR response to a frozen high-arctic firn pack. As a result of extensive summertime percolation, the firn pack comprises a high fraction of ice layers, lenses, and vertical glands. We show that the GPR response on the firn pack mainly depends on the following: 1) the thickness of the ice layers; 2) the distance between layers; 3) the layer roughness; and 4) the presence or absence of elliptical ice lenses. Using 3-D FDTD modeling, we show that the GPR is not sensitive to typical ice glands, which implies that the GPR underestimates firn heterogeneity, such that firn stratigraphy in percolation and wet-snow zones could be incorrectly interpreted as being better preserved than it actually is. We find that thin ice layers (< 0.05 m) or multiple thin ice layers give a strong response. Thicker ice layers typically give a weaker backscatter per unit area, mainly due to the lack of interference of the reflections from the upper and lower interfaces, but are, due to their continuity, easily trackable. Ice layers with a thickness comparable to the GPR wavelength give 180. phase-shifted upper and lower reflections and are, in general, separated by a band of low GPR response, due to the lack of permittivity contrast within the ice layers. Despite the ice lenses' relatively short horizontal correlation length, as inferred from cores, bands of high-amplitude clutter caused by these features can be traced over several kilometers in GPR profiles.

• Brandt, Ola; Langley, Kirsty; Giannopoulos, Antonios; Hamran, Svein-Erik & Kohler, Jack (2009). Radar Response of Firn Exposed to Seasonal Percolation, Validation Using Cores and FDTD Modeling. IEEE Transactions on Geoscience and Remote Sensing. ISSN 0196-2892. 47(8), p. 2773–2786. doi: 10.1109/TGRS.2009.2016555.
• Langley, Kirsty A; Lacroix, P; Hamran, Svein-Erik & Brandt, O (2009). Sources of backscatter at 5.3 GHz from a superimposed ice and firn area revealed by multi-frequency GPR and cores. Journal of Glaciology. ISSN 0022-1430. 55(190), p. 373–383.
• Lacroix, P; Legresy, B; Langley, Kirsty A; Hamran, Svein-Erik; Kohler, Jack & Roques, S [Show all 7 contributors for this article] (2008). In situ measurements of snow surface roughness using a laser profiler. Journal of Glaciology. ISSN 0022-1430. 54(187), p. 753–762.
• Langley, Kirsty; Hamran, Svein-Erik; Høgda, Kjell Arild; Hogda, KA; Storvold, Rune & Brandt, Ola [Show all 7 contributors for this article] (2008). From glacier facies to SAR backscatter zones via GPR. IEEE Transactions on Geoscience and Remote Sensing. ISSN 0196-2892. 46(9), p. 2506–2516. doi: 10.1109/TGRS.2008.918648.
• Langley, Kirsty A; Hamran, Svein-Erik; Hogda, KA; Storvold, R; Brandt, O & Hagen, Jon Ove Methlie (2007). Use of C-band ground penetrating radar to determine backscatter sources within glaciers. IEEE Transactions on Geoscience and Remote Sensing. ISSN 0196-2892. 45(5), p. 1236–1246. doi: 10.1109/TGRS.2007.892600.
• Brandt, O; Langley, Kirsty; Kohler, Jack & Hamran, Svein-Erik (2007). Detection of buried ice and sediment layers in permafrost using multi-frequency Ground Penetrating Radar: A case examination on Svalbard. Remote Sensing of Environment. ISSN 0034-4257. 111(2-3), p. 212–227. doi: 10.1016/j.rse.2007.03.025.
• Lecomte, Isabelle; Hamran, Svein-Erik & Gelius, Leiv-J. (2005). Improving Kirchhoff migration with repeated local plane-wave imaging? A SAR-inspired signal-processing approach. Geophysical Prospecting. ISSN 0016-8025. 53, p. 767–785.
• Hamran, Svein-Erik; Lecomte, Isabelle & Gelius, Leiv-J. (2003). Local Plane-Wave Imaging of GPR Data. Journal of Environmental & Engineering Geophysics. ISSN 1083-1363. 8, p. 115–121.
• Lecomte, I.; Gelius, Leiv-J. & Hamran, Svein-Erik (2002). Local imaging approach and applications. In EAGE, . (Eds.), Extended Abstracts Book: 64th EAGE Conference and Technical Exhibition, Florence, Italy. EAGE. ISSN 9789073781207.
• Hodkins, R.; Hagen, Jon Ove Methlie & Hamran, Svein-Erik (1999). Twentieth-Century Mass Balance and Thermal Regime Change at an Arctic Glacier. Annals of Glaciology. ISSN 0260-3055. 28, p. 216–220.
• Hagfors, T; Dalstrøm, I.; Gold, T.; Hamran, Svein-Erik & Hansen, Roy Edgar (1997). Refraction Scattering in the Anomalous Reflections from Icy Surfaces. Icarus (New York, N.Y. 1962). ISSN 0019-1035. 130(2), p. 313–322.
• Ødegård, Rune Strand; Hagen, Jon Ove Methlie & Hamran, Svein-Erik (1997). Comparison of radio-echo sounding (30MHz-1000MHz) and high resolution borehole temperature measurements at Finsterwalderbreen, southern Spitsbergen, Svalbard. Annals of Glaciology. ISSN 0260-3055. 24, p. 262–267.
• Hamran, Svein-Erik; Aarholt, E.; Hagen, Jon Ove Methlie & Moe, Peter J. (1996). Estimation of relative water content in a sub-polar glacier using surface-penetrating radar. Journal of Glaciology. ISSN 0022-1430. 42(142), p. 533–537.
• Bjørnsson, Helgi; Gjessing, Yngvar; Hamran, Svein-Erik; Hagen, Jon Ove Methlie; Liestøl, O. & Pàlsson, F. (1996). Temperature regime of sub-polar glaciers mapped by multi-frequency radio-echo sounding. Journal of Glaciology. ISSN 0022-1430. 42(140), p. 23–32.
• Ødegård, Rune Strand; Hamran, Svein-Erik; Bø, P.H.; Etzelmuller, Bernd; Vatne, Geir & Sollid, Johan Ludvig (1992). Thermal regime of a valley glacier, Erikbreen, northern Spitsbergen. Polar Research. ISSN 0800-0395. 11, p. 69–80.

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• Aardal, Øyvind; Brovoll, Sverre; Berger, Tor; Balasingham, Ilangko & Hamran, Svein-Erik (2017). Phase distortions in radar respiration monitoring.
• Hamran, Svein-Erik; Øyan, Mats Jørgen & Skaugvoll, Grethe (2016). FFI lager Mars-radar for Nasa. Show summary

  I denne podcasten har vi tatt en prat med tre radarforskere som alle jobber for fullt for å få ferdig Rimfax, radaren som skal hjelpe Nasa lete etter liv på Mars.

• Berger, Tor; Hamran, Svein-Erik; Ødegaard, Nina; Øyan, Mats Jørgen & Damsgård, Leif (2015). Stripmap Autofocus of Short Range Ku-band Synthetic Aperture Radar Data.
• Brovoll, Sverre; Berger, Tor; Aardal, Øyvind; Lande, Tor Sverre & Hamran, Svein-Erik (2014). Distortion effects in a switch array UWB radar for time-lapse imaging of human heartbeats.
• Aardal, Øyvind; Brovoll, Sverre; Paichard, Yoann; Berger, Tor; Lande, Tor Sverre & Hamran, Svein-Erik (2013). Detecting changes in the human heartbeat with on-body radar.
• Brovoll, Sverre; Berger, Tor; Paichard, Yoann; Aardal, Øyvind; Lande, Tor Sverre & Hamran, Svein-Erik (2013). Time-lapse imaging of human heartbeats using UWB radar.
• Brovoll, Sverre; Aardal, Øyvind; Paichard, Yoann; Berger, Tor; Lande, Tor Sverre & Hamran, Svein-Erik (2013). Optimal frequency range for medical radar measurements of human heartbeats using body-contact radar.
• Klaveness, Dag; Dypvik, Henning & Hamran, Svein-Erik (2012). The Ål stucture.
• Langley, K.; Sinisalo, A.; Kohler, Jack; Hamran, Svein-Erik; Øyan, Mats Jørgen & Smedsrud, Lars Henrik [Show all 9 contributors for this article] (2011). A look at the basal mass balance ofthe Fimbul ice shelf using ice penetrating radar andoceanographic borehole data.
• (2010). An efficient scaled maximum likelihood algorithm for translational motion estimation in ISAR imaging. Show summary

  In ISAR imaging, the relative motion between the target and the radar must be known precisely to produce focused radar images. The translational motion of the target must be compensated for to use only the rotational motion around a fixed centre point for the imaging of the target. An efficient implementation of a maximum likelihood (ML) algorithm for translational motion estimation based on the Chirp-Z transform is described. If the line of sight vector from the radar to the target is not within the rotational plane of the object, or the rotational plane changes during the observation time, and strong reflectors tend to bias the estimate of translational motion. A scaling of range profiles is shown to reduce the bias. The shear average algorithm is similar to the algorithm described here, but it only estimates translational motion to within half the carrier wavelength. Simulated and experimental data are used to show the effectiveness of the algorithm. An image sharpness measure is used to indicate the effects of scaling as a preprocessing step on experimental data. All results are compared to those obtained by shear average and prominent point processing techniques.

• (2010). ISAR imaging of small aircraft. Show summary

  In ISAR imaging, the relative motion between the target and the radar must be known precisely to produce focused radar images. The translational motion of the target must be compensated for in order to use only the rotational motion around a fixed centre point for the imaging of the target. Different methods for range alignment can be used, and the success depends much on the nature of the data. If strong reflectors are dominant throughout the observation period, a prominent point processing (PPP) method may produce good results. If not, other methods may apply. The advantage of using PPP is simplicity in concept and its processing speed. Another method, in general slower than PPP, is based on maximum likelihood estimation of translational motion. An maximum likelihood algorithm for translational motion estimation (TME) is described. Data from the German research radar TIRA at FGAN-FHR is processed to show the potential of the algorithms. Also, after range alignment, the kurtosis (fourth order central moment) of averaged range profiles gives an indication of which of the two methods that gives the best results in terms of image sharpness. Data from TIRA of a small aircraft is collected over a period of minutes and are processed in five second intervals with 80 % overlap. The results from the PPP and the TME algorithms are compared, automatically in terms of a sharpness measure, and also by user inspection. The results indicate that for low kurtosis regions the TME method should be used, while for high kurtosis regions, the PPP method is preferred. In this way the total processing time can be reduced for multi image sequences, as we use the PPP method whenever we can and the TME method whenever we have to.

• Müller, Karsten; Anschütz, Helgard; Sinisalo, Anna Katariina; Hamran, Svein-Erik; Hagen, Jon Ove Methlie & McConnell, Joseph [Show all 7 contributors for this article] (2009). Surface mass balance along the Norwegian/U.S. scientific traverse across East Antarctica.
• Müller, Karsten; Sinisalo, Anna Katariina; Anschütz, Helgard; Hamran, Svein-Erik; Hagen, Jon Ove Methlie & McConnell, Joseph (2009). An 860km accumulation rate profile on the East Antarctic plateau derived by GPR.
• Müller, Karsten; Albert, Mary; Hamran, Svein-Erik & Hagen, Jon Ove Methlie (2008). Radar Scattering Zones across Dronning Maud Land, East Antarctica.
• Müller, Karsten; Hamran, Svein-Erik; Hagen, Jon Ove Methlie & Sinisalo, Anna Katariina (2008). Relation between GPR, SAR and accumulation rate in the dry-snow zone of East Antarctica.
• Hamran, Svein-Erik; Klaveness, Dag & Dypvik, Henning (2008). GPR Reveals a Sub Bottom Anomaly Inside a Circular Basin in a Small Lake.
• Gelius, Leiv-J.; Lecomte, I. & Hamran, Svein-Erik (2002). The concept of Local Parabolic-Wave Imaging (LpI)in PSDM doi: 10.1190/1.1816862.
• Hamran, Svein-Erik; Lecomte, I. & Gelius, Leiv-J. (2002). GPR processing using local Plane-wave Imaging.
• Lecomte, I.; Hamran, Svein-Erik; Tabti, Hocine & Gelius, Leiv-J. (2001). New Insights in migration Through analogies between Generalized Diffraction Tomography and Synthetic Aperture Radar. doi: 10.1190/1.1816279.
• Hamran, Svein-Erik; Hagen, Jon Ove Methlie & Ødegård, Rune Strand (2000). Glacier radar Sounding Using Multiple Frequency bands.
• Bjørnsson, Helgi; Erlingsson, B.; Gjessing, Yngvar; Hagen, Jon Ove Methlie; Hamran, Svein-Erik & Liestøl, O. (1992). Temperature regime of sub-polar glaciers mapped by multi-frequency synthetic aperture radar.
• (2015). Tomographic scanning imager. Akademika forlag. ISSN 1501-7710.
• Aardal, Øyvind; Hamran, Svein-Erik; Lande, Tor Sverre & Berger, Tor (2013). Radar monitoring of heartbeats and respiration. Akademika forlag.
• Hamran, Svein-Erik; Gunneriussen, T.; Hagen, Jon Ove Methlie & Ødegård, Rune Strand (1997). Ground Penetrating Radar and ERS SAR Data for Glacier Monitoring. Proceedings IGARSS-97..

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