SBIR-STTR Award

Groundwater represents about a third of global water withdrawals, and approximately half of global irrigation water. In many arid and semi-arid regions, groundwater is rapidly being depleted, which is affecting agricultural productivity over the long term. The over-exploitation of groundwater due to the current drought episode in South-Western U.S. has already led farmers to fallow hundreds of thousands of acres of farmland. Informed assessments and policies related to groundwater supplies can only be made on the basis of large-scale, precise estimates of depletion and recharge. However, current technologies have poor resolution in time and/or in space. We propose to leverage very recent advances in artificial intelligence applied to Interferometric Synthetic Aperture Radar (InSAR) in order to study groundwater depletion and recharge. Variations in groundwater levels induce deformation at the surface of the Earth, which can be captured by satellite-based InSAR measurements. Our technology allows to lower the detection threshold of surface deformation in InSAR time series by about an order of magnitude compared to the state-of-the-art; the associated resolution in space is a few km with a time resolution of roughly a week, thereby potentially offering a new tool for groundwater management decisions. Potential NASA Applications (Limit 1500 characters, approximately 150 words): The tools proposed in this Phase I proposal will rely extensively on NASA data, by analyzing partly processed InSAR data available on NASA's Earth Data portal. NASA is also about to launch a new InSAR constellation (NISAR) in 2023, and we will rely on these data for Phase II of this project. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): The market of groundwater estimates is centered around two major types of clients: agricultural businesses wanting to perform groundwater exploration and assess whether they are using their groundwater resources in a sustainable way, and local and state governments seeking to better quantify and understand local and regional water resources. Duration: 6

Groundwater represents about a third of global water withdrawals, and approximately half of global irrigation water. In many arid and semi-arid regions, groundwater is rapidly being depleted, which is affecting agricultural productivity over the long term. The over-exploitation of groundwater due to the current drought episode in South-Western U.S. has already led farmers to fallow hundreds of thousands of acres of farmland. We leverage recent developments in artificial intelligence in order to improve deformation detection thresholds in Interferometric Synthetic Aperture Radar (InSAR). Our technology allows to deconvolve signal from noise in InSAR data, and lowers the detection threshold of surface deformation in spatially continuous InSAR time series of ground deformation by about an order of magnitude compared to the state-of-the-art. Phase I focused on separating ground deformation signals from atmospheric noise, and improving the time resolution of the associated InSAR time series. In this Phase II proposal, we focus on further improving detection capabilities by taking directly into account a second major source of noise in InSAR data, due to soil moisture. We specifically train models on time series of seasonal depletion and recharge in order to study variations in groundwater levels in InSAR data, with the goal of allowing governments and organizations to take informed assessments and policies related to groundwater supplies. Anticipated

Benefits:
NASA is about to launch a new satellite constellation for InSAR (NiSAR), with a planned launch date in 2023, and our proposed technology could be applied to data provided by this new constellation. Moreover, our algorithm could be interfaced with InSAR interferogram data from NASA Earthdata, and can be used in combination with NASA code libraries (isce, AriaTools). Last, the NASA Observational Products for End-Users from Remote Sensing Analysis (OPERA) project started in April 2021, and our proposed work could be coupled to OPERA products. Our other commercialization applications are targeting several sectors: i) farming; ii) state and local governments, with the goal of helping monitor groundwater resources; iii) the insurance sector, and in particular insurance products related to flooding and drought; and iv) the finance sector, to help anticipate changes in the price of oil and gas, as well as water.