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Satellite telemetry is a key method to study cetacean movements, but it is limited by sparse location data and positional errors. Positions are recorded only when animals surface and satellite coverage is available, creating large temporal gaps and reducing the resolution of behavioral insights, particularly for species that spend little time at the surface. Although state-space models can predict animal locations, their accuracy depends on the density and precision of positional data. Enhancing data availability through complementary sources, such as auxiliary telemetry signals, can therefore strengthen ecological interpretations. This study investigates whether the received signal power of ultra-high-frequency (UHF) messages, detected by a CLS goniometer antenna (18.7 m a.s.l.), can serve as a proxy for estimating distance from the antenna and provide additional location data. Data were collected from 11 goose-beaked whales (Ziphius cavirostris) tagged in the mid-latitude Ligurian Sea (North-West Mediterranean Sea). Across these deployments, 95% of messages were received when transmitting platforms were within 15 km of the antenna. The relationship between received signal power and distance was strong (conditional R² = 0.90), indicating that this metric is a reliable proxy for estimating whale distance. In total, the goniometer provided 1,278 potential locations, with contributions per individual ranging from 19 to 249. When these goniometer-derived locations were excluded, the mean interval between fixes increased by 43% (95% CI: 31–57%), underscoring the substantial contribution of these additional data to improving the temporal resolution of movement records. Our study provides a practical approach to reduce data gaps in satellite telemetry by integrating goniometer-derived locations into state-space models. Incorporating information from the goniometer increases location density, improves track continuity, and enhances the reliability of ecological inferences. With appropriate consideration of antenna configuration and deployment context, this approach is scalable and transferable to other marine species and telemetry systems, particularly in cases where conventional satellite-derived positions are sparse or unreliable.