The Mahali Project: Deployment Experiences From A Field Campaign In Alaska

The Mahali Space Weather Monitoring project, funded by the U.S. National Science Foundation, has a research goal of forming a global space weather monitoring network based on an architecture that utilizes GNSS receivers powered by solar panels, wireless communication, and mobile devices, such as phones and tablets. Mahali concepts strategically exploit existing GNSS infrastructure - more specifically, delays in multi-frequency GNSS signals - to acquire a vast set of global total electron content (TEC) estimates. With connectivity available worldwide, mobile devices are excellent candidates to establish crowd sourced global relays that feed multi-frequency GNSS sensor data into a cloud-processing environment. Once the GNSS data is in the cloud, a picture of Earth's near space environment, and its dynamic changes, can be reconstructed and broadcast globally.This paper focuses specifically on Mahali project research that directly addresses the feasibility of establishing a network of receivers in remote, hard to access, locations. We describe here a recent deployment of nine Wi-Fi enabled Mahali boxes in Alaska. Each of these Mahali boxes consists of a solar panel, a battery, a GPS receiver and antenna, a small micro-computer, and a Wi-Fi access point. For crowd-sourced data access, regular smartphones were equipped with a specific Mahali data relay application ("app") allowing for easy data download from the Mahali box and data upload to the cloud. The relay and crowdsourcing through the app were necessary because there were no network connections, or even cell phone coverage, at the majority of the deployment locations. Mahali boxes were located along the Dalton and Steese highways in Alaska at locations up to 100 miles northeast and northwest of the Poker Flat Research Range (PFRR), a US National Aeronautics and Space Administration (NASA) suborbital rocket launch facility near Fairbanks, Alaska. Alaska is in a particularly interesting geophysical location in the subauroral/auroral region due to its proximity to important atmospheric boundaries where rapid motions, dynamic energy input, and other high latitude effects occur. Furthermore, ionospheric impacts from intense geomagnetic disturbances, such auroras, are frequently viewed. The longer similar to 100 mile GNSS baselines enabled by the Mahali project contain significant ionospheric information that, when extracted, allow reconstruction of the movement of ionospheric irregularities produced by auroral disturbances. Mahali data are also well suited for energy and momentum transfer studies that examine sources such as atmospheric gravity waves, along with volumetric studies of auroral arcs and other ionospheric fine-scale structure.