TY - JOUR
T1 - Airborne Sounding Radar for Desert Subsurface Exploration of Aquifers
T2 - Desert-SEA: Mission concept study [Space Agencies]
AU - Heggy, Essam
AU - Moghaddam, Mahta
AU - Palmer, Elizabeth M.
AU - Brown, William M.
AU - Blanton, J. Lee
AU - Kosinski, Mikolaj
AU - Sirri, Paul
AU - Dixon, Edgar A.
AU - Abotalib, Abotalib Z.
AU - Normand, Jonathan C.L.
AU - Clark, John
AU - Klemens, Gary
AU - Agranier, Matthieu
AU - Guillon, Francois
AU - Abdellatif, Akram A.
AU - Khattab, Tamer
AU - Tsvetanov, Zlatan
AU - Shokry, Mohamed
AU - Al-Mulla, Noor
AU - Ramah, Mohamed
AU - Bateni, Sayed M.
AU - Tabatabaeenejad, Alireza
AU - Avouac, Jean Philippe
N1 - Publisher Copyright:
© 2013 IEEE.
PY - 2024/3/1
Y1 - 2024/3/1
N2 - Shallow aquifers are the largest freshwater bodies in the North African Sahara and the Arabian Peninsula. Their groundwater dynamics and response to climatic variability and anthropogenic discharge remain largely unquantified due to the absence of large-scale monitoring methods. Currently, the assessment of groundwater dynamics in these aquifer systems is made primarily from sporadic well logs that barely cover a few percent of the geographical extent of these water bodies. To address this deficiency, we develop the use of an ultra-wideband (UWB) very high frequency (VHF) interferometric airborne sounding radar, under a collaboration between NASA and the Qatar Foundation, to characterize the depth and geometry of the shallowest water table in large hyperarid hydrological basins in North Africa and the Arabian Peninsula. Herein, we describe the science objectives, measurement requirements, instrument design, expected performance, flight implementation scenarios, primary targets for investigation, and the first technology demonstration of the concept. Our performance analyses suggest that an airborne, nadir-looking sounding radar system operating at a 70-MHz center frequency with a linearly polarized folded-dipole antenna array - enabling a bandwidth (BW) of 50 MHz - and a surface signal-to-noise ratio (SNR) of 85 dB flying at an altitude of 500-2,000 m can map the uppermost water table depths of aquifer systems spanning tens of kilometers at a vertical resolution of 3 m in desiccated terrains to an average penetration depth of 50 m, with a spatial resolution of 200 m. For the first time, this airborne concept will allow time-coherent high-resolution mapping of the uppermost water tables of major aquifer systems in hyperarid areas, providing unique insights into their dynamics and responses to increasing climatic and anthropogenic stressors, which remain largely uncharacterized. The aforementioned significantly surpasses the existing capabilities for mapping shallow aquifers in these harsh and remote environments, which relies today on data collected on different timescales from sparse well logs that do not cover their geographic extents. A list of key abbreviations for this article can be found in 'The Key Abbreviations Used in This Article.'
AB - Shallow aquifers are the largest freshwater bodies in the North African Sahara and the Arabian Peninsula. Their groundwater dynamics and response to climatic variability and anthropogenic discharge remain largely unquantified due to the absence of large-scale monitoring methods. Currently, the assessment of groundwater dynamics in these aquifer systems is made primarily from sporadic well logs that barely cover a few percent of the geographical extent of these water bodies. To address this deficiency, we develop the use of an ultra-wideband (UWB) very high frequency (VHF) interferometric airborne sounding radar, under a collaboration between NASA and the Qatar Foundation, to characterize the depth and geometry of the shallowest water table in large hyperarid hydrological basins in North Africa and the Arabian Peninsula. Herein, we describe the science objectives, measurement requirements, instrument design, expected performance, flight implementation scenarios, primary targets for investigation, and the first technology demonstration of the concept. Our performance analyses suggest that an airborne, nadir-looking sounding radar system operating at a 70-MHz center frequency with a linearly polarized folded-dipole antenna array - enabling a bandwidth (BW) of 50 MHz - and a surface signal-to-noise ratio (SNR) of 85 dB flying at an altitude of 500-2,000 m can map the uppermost water table depths of aquifer systems spanning tens of kilometers at a vertical resolution of 3 m in desiccated terrains to an average penetration depth of 50 m, with a spatial resolution of 200 m. For the first time, this airborne concept will allow time-coherent high-resolution mapping of the uppermost water tables of major aquifer systems in hyperarid areas, providing unique insights into their dynamics and responses to increasing climatic and anthropogenic stressors, which remain largely uncharacterized. The aforementioned significantly surpasses the existing capabilities for mapping shallow aquifers in these harsh and remote environments, which relies today on data collected on different timescales from sparse well logs that do not cover their geographic extents. A list of key abbreviations for this article can be found in 'The Key Abbreviations Used in This Article.'
KW - Arabian peninsula
KW - Bir-safsaf
KW - Climate-change
KW - Egypt
KW - Evolution
KW - Groundwater
KW - Low-frequency radar
KW - Northern africa
KW - Sahara
KW - System
UR - http://www.scopus.com/inward/record.url?scp=85187554030&partnerID=8YFLogxK
U2 - 10.1109/MGRS.2023.3338512
DO - 10.1109/MGRS.2023.3338512
M3 - Article
AN - SCOPUS:85187554030
SN - 2473-2397
VL - 12
SP - 162
EP - 185
JO - IEEE Geoscience and Remote Sensing Magazine
JF - IEEE Geoscience and Remote Sensing Magazine
IS - 1
ER -