INTRODUCTION

The National Oceanic and Atmospheric Administration (NOAA) relies on the GOES satellite
system to monitor weather, climate, and environmental hazards across the Western
Hemisphere. A core function of this system is the Data Collection System (DCS), which
receives real-time environmental data from a global network of ground-based sensors
supporting applications such as volcanic monitoring, tsunami alerts, and dam safety.

However, persistent RF interference in the UHF uplink band (401–403 MHz) can disrupt this
data flow, degrading the reliability of vital alerts and measurements. One such disruption
impacted the overlapping coverage area of GeoXO West and GeoXO East, with interference
traced to the region surrounding Quito, Ecuador. The source was unknown, and the
consequences were significant.

NOAA’s Data Collection System (DCS) depends on a network of sensors transmitting data to GOES satellites. These data are used for:

The GOES DCS system had been experiencing continuous interference, hindering uplink performance for environmental sensors across a wide area. These disruptions affected not only scientific measurements but also time-sensitive applications such as seismic and volcanic activity alerts.

While NOAA could study the signal’s characteristics, the origin remained hidden. The signal offered no identifiable source, and the GOES satellites’ coverage area spans nearly one-third of the Earth, making geolocation a complex challenge.

The vast coverage area of the GOES satellites spans thousands of kilometers, making interference detection a daunting challenge. Within and around the overlapping region of GeoXO West and GeoXO East, a persistent signal disrupted critical data transmission until advanced RF geolocation techniques pinpointed the source.

STEPS TAKEN TO IDENTIFY THE SOURCE

Given the GOES satellites’ vast footprint, pinpointing a single disruptive transmission was like searching for a needle in a haystack. NOAA sourced HawkEye 360 to conduct a targeted investigation, leveraging commercial space-based radio frequency (RF) data. RF data, emitted by almost all radios, radars, and navigation tools, is detected and geolocated from orbit to reveal patterns of activity, interference, or misuse across large, remote regions.

Over a focused period, HawkEye 360 provided data from 80 satellite collections over Ecuador, which helped isolate and define the interference signature. This multi-pass approach created a dense dataset for signal detection, progressively refining the geolocation area and building confidence in the results.

HawkEye 360’s satellite collection footprint quickly covered the search area, enabling signal detection across a broad region with high revisit rates. This image shows a single UHF collection footprint—one of many that quickly covered the search area, pinpointing the interference source in about a week.

STEPS HAWKEYE 360’S DEFENSE-GRADE APPROACH TO A CIVIL CHALLENGETAKEN TO IDENTIFY THE SOURCE

While this mission supported a civil agency, HawkEye 360 applies the same defense-grade signals intelligence capabilities used across national security and allied operations. As a leader in space-based RF monitoring, HawkEye 360 delivers high-confidence RF intelligence to illuminate interference sources that are otherwise difficult to detect or attribute.

Through proprietary tools like RFGeo™ and RFIQ™, along with additional mission-partner signal analysis platforms, HawkEye 360 detects, characterizes, and geolocates RF emissions with precision. These capabilities enable rapid response to persistent interference, providing decision-makers with the actionable insights they need to protect critical systems and restore operational continuity.

RESOLUTION: LOCAL ACTION ENABLED BY GLOBAL RF INTELLIGENCE

Based on HawkEye 360’s findings, Ecuador’s national telecommunications authority (ARCOTEL) and the Instituto Geofísico (IG-EPN) launched a high-altitude field expedition to investigate the suspected source: the remote PINO seismic station on the active Guagua Pichincha volcano, just outside Quito. Located at over 15,000 feet above sea level, the site presented a challenging ascent, requiring teams to hike through steep volcanic terrain to reach the suspected location.

The rugged slopes of Guagua Pichincha volcano near Quito, Ecuador, where field teams ascended to over 15,000 feet to access a remote seismic station and dismantle the source of persistent RF interference.
Image: “Ecuador – Crater GuaguaPichincha.JPG” via Wikimedia Commons. Licensed under the GNU Free Documentation License.

Upon arrival, the team identified and dismantled an unused analog radio system, an outdated communications device that had previously supported volcano monitoring but was no longer operational. According to ARCOTEL, the equipment was fully removed in accordance with technical protocols, and UHF interference ceased immediately. Routine spectrum monitoring will continue as part of Ecuador’s ongoing regulatory oversight.

This resolution highlights the value of actionable RF intelligence in enabling complex, high-impact field operations and restoring continuity to critical satellite systems.

Geolocations shown here (red dots) represent signals captured within a 10km radius of the volcano. This tight cluster confirmed the interference source, enabling precise identification and resolution of the disruptive transmission.
* This data representation has been degraded. The image contains commercial data and information. It contains no “technical data.” Contains information that is only representative of information that can be produced from the use or operation of a defense article.

CONCLUSION & IMPACT

This case demonstrates the critical role that space-based RF intelligence plays in resolving real-world civil challenges. HawkEye 360’s ability to identify and characterize a persistent UHF signal, detect emissions across multiple satellite passes, and geolocate the source with precise accuracy enabled NOAA and Ecuadorian authorities to take decisive action. The successful remediation of this long-standing interference restored functionality to a vital satellite system supporting environmental monitoring and hazard response.

Key contributions included:

  • Identifying and characterizing a persistent, unauthorized UHF signal
  • Detecting emissions across multiple satellite passes
  • Geolocating the interference source with precise accuracy
  • Delivering time-correlated RF intelligence that enabled real-world field remediation

As RF spectrum congestion continues to grow, the need for timely, independent geolocation and interference attribution is more urgent than ever. HawkEye 360 remains committed to delivering the intelligence our partners need to protect critical infrastructure and ensure continuity of operations across civil, commercial, and defense missions.