Global Ionosphere Model Validation Using HAARP and WSPR

This paper describes initial measurements of HF radio propagation from the High-frequency Active Auroral Research Program (HAARP) transmitter in the 40-m and 80-m ham bands to locations throughout Canada and the United States using the volunteer Weak Signal Propagation Reporter (WSPR) network. The HAARP beam power, gain, direction, and polarization were varied during the experiment. Comparisons of WSPR reports of HAARP signal strength throughout North America are made with predictions from the Voice of America Coverage Analysis Program (VOACAP) for HF Propagation Prediction and Ionospheric Communications Analysis. Opportunities for future Citizen Science experiments with HF propagation from facilities such as HAARP are explored.

HF radio propagation forecasting and modeling is still a hard problem – even more so with forecasting and modeling HF propagation in and from high latitude regions. One key problem to solve is availability of data for validating and improving global ionosphere models. Available real-time and archival space weather data for forecasting and modelling is still very sparse relative to troposphere weather data regularly collected from ground weather stations, radiosondes, and radars. Prior to 1850, meteorological data was also very sparse. Significant misunderstandings about causal relationships between weather observations persisted until the turn of the century, when a network of volunteer amateurs – organized under the new US Weather Bureau – began reporting weather observations by way of telegraph that were centrally collected and widely published. This network of Citizen Scientist weather observers soon led to rapid advancements in weather forecasting. Today, there are similar opportunities for Citizen Science data to transform aspects of space weather forecasting and modelling, especially with the recent proliferation of consumer software defined radios (SDRs) online and set up to continuously monitor the radio spectrum.

Recent experiments conducted at the University of Alaska Fairbanks Geophysical Institute HAARP Ionospheric and Radio Science Laboratory have demonstrated that the WSPR network – maintained by hams and radio enthusiasts – can be used in conjunction with the 40-acre phased array HF transmitter at HAARP to create real time maps of HF radio propagation from a variable source in the Subarctic. While HAARP is typically used for ionosphere radio modification experiments with net radiated HF powers of up to 3600 kilowatts in near vertical incidence, the transmitter itself is highly configurable and capable of low power operations at low and variable elevation angles. HAARP is capable of modulating the beam in amplitude or frequency sufficient for many digital communication modes such as the MEPT_JT digital mode used by the WSPR network.