GNSS

Researchers from the School of Geodesy and Geomatics at Wuhan University, the Chinese Antarctic Center of Surveying and Mapping, the University of Electronic Science and Technology of China and Baidu Online Network Technology published a study on 30 September 2026 in Satellite Navigation. The paper presents a residual-based machine learning (ML) validator for GNSS ambiguity resolution in challenging environments. It combines residual-based features with a compact Multilayer Perceptron to decide whether a fixed integer ambiguity solution should be accepted.

The validator extracts three key residual- based features: Ambiguity Difference Root Mean Square (ADR), Phase Residuals Root Mean Square (PRR), and Phase Consistency Root Mean Square (PCR). PRR measures post-
fit carrier-phase residuals, while PCR checks consistency between frequencies after ambiguities are fixed. In feature- importance tests, PRR and PCR were the most influential, with stronger correlations to wrong/correct labels than conventional indicators. The classifier is a single-hidden-layer MLP with only 16 hidden neurons, a model size of about 2.8 KiB, and an inference time of 28ms for more than 350,000 samples. On a 260-hour UGV dataset from Suzhou and a 240-km car dataset from Wuhan, it achieved accuracy and precision above 90%. In UGV tests, the average correct fixing rate reached 85.21%, versus 77.26% for FFRT, while the wrong fixing rate fell to 1.42% from 16.37%. In the CAR-S5 urban scenario, the correct fixing rate was 85.15%, an improvement of 10.55% over FFRT, with a wrong fixing rate of 0.92%. In addition, the proposed method requires an average of only 1.244 ms per epoch for ambiguity resolution, compared with more than 5 ms for the other methods. On the public SmartPNT- POS dataset, it reached a 72.40% correct fixing rate and a 4.50% wrong fixing rate, outperforming POSM and FlexRTK.

The authors said the key advance is not simply adding ML, but giving it residual- based evidence that remains informative when conventional statistical assumptions break down. They said the most influential features were PRR and PCR, which directly test whether the fixed ambiguities are consistent with the carrier-phase observations. They said the compact MLP was chosen deliberately, because real- time GNSS users need low latency and small memory footprints. They added that the method reduces both missed and wrong fixes, although performance may still degrade under extremely weak observation models or severely biased float solutions. www.eurekalert.org

Ukrainian and Polish specialists in geodesy, cadastre, photogrammetry and land management are turning years of professional contacts into systematic cooperation, with joint research, academic visits, an international webinar, publications and student exchange among the planned activities. Against this backdrop, on 9 October 2026, the first joint online meeting was held between the Department of Geodesy and Cartography at NUBiP of Ukraine and the Department of Agricultural Geodesy, Cadastre and Photogrammetry at the University of Agriculture in Krakow (URK). The meeting marked an important step from long-standing professional contacts towards a structured, long-term partnership between the two departments.

Iran’s National Cartographic Center (NCC) is strengthening its cooperation with the Iranian Space Agency (ISA) to improve the country’s spatial data infrastructure. Under a joint MoU, cartography and remote-sensing specialists are processing imagery from the Khayyam satellite, aligning it with existing spatial coordinates and adjusting image resolution to meet national standards. The cooperation aims to combine satellite imagery with spatial information obtained from gravimetry. Khayyam provides nationwide coverage and its imagery is processed at different scales, including 1:25,000 and 1:2,000.

Skyband Systems Inc. has announced that the M100, the world’s first avionics unit to combine Iridium positioning, navigation, and timing (PNT) with inertial sensing, has entered production. The M100 alerts flight crews in real time to GPS spoofing and jamming and provides position and timing using Iridium’s low-Earth orbit (LEO) satellite network.

NorthStandard has entered into a partnership with SGM Technology to offer its Members the innovative PntGuardTM platform for authenticating ship position signals in real time on preferential terms, to help them overcome incidents of GNSS jamming and spoofing.