Title: Aloft Sensing’s Stratospheric InSAR Instrument and Embedded PNT Module for STV Distributed Sensing
Presenting Author: Lauren Wye
Organization: Aloft Sensing, Inc.
Co-Author(s): Patrick Rennich, Brian Pollard

Abstract:
This presentation reviews progress on two ESTO-sponsored Aloft Sensing, Inc. (Aloft) efforts: 1) our Instrument Incubator Program (IIP) 2022-2025 project “High Altitude, Long Endurance (HALE) InSAR for Continual and Precise Measurement of Earth’s Changing Surface”, and 2) our Decadal Survey Incubation (DSI) 2022-2025 project “Embedded PNT Module for Distributed Radar Sensing." Both projects leverage Aloft’s patented radar-based PNT (positioning, navigation, and timing) techniques to enable breakthrough sensing and navigation methods. Under our IIP project, Aloft is developing a breakthrough compact radar system for deployment on HALE or HAPS (High Altitude Platform Stations) stratospheric vehicles. These emerging platforms offer the unmatched ability to persistently observe science targets and capture the dynamics of rapidly evolving surface vegetation and topographic phenomena. Aloft’s radar system employs the Aloft PNT techniques to minimize instrument size, weight, and power (SWaP), and to overcome the challenges associated with generating high-quality synthetic aperture radar (SAR) and interferometric SAR (InSAR) products from HALE platforms in the stratosphere. Stratospheric flight testing of the InSAR instrument is scheduled to commence in summer 2024. Under our DSI project, Aloft is developing and testing a prototype PNT module that delivers high-precision positioning and timing solutions in real-time. The module, comprising custom-built digital hardware and GPU-embedded algorithms, supports vehicle navigation independently of GPS, and, importantly for NASA Surface Topography and Vegetation (STV) science investigations, enables a new type of distributed multi-baseline radar product, delivering the high levels or precision required for coherent alignment of complex radar imagery across platforms in support of emerging techniques such as polarimetric InSAR (PolInSAR) and tomographic SAR (TomoSAR). These techniques are critical for STV efforts to achieve accurate 3-D volumetric reconstructions of surface vegetation and other structures. The PNT module can also serve as radar sensor in its own right, as well as support other sensing instruments in need of rapid and accurate relative positioning information. Airborne testing of the PNT module is scheduled to commence in summer 2024.