Anders Rødningsby

• Solend, Tor Atle; Rødningsby, Anders & Moen, Hans Jonas Fossum (2025). Impacts of infrared thermographic image blurring on UAV inspection efficiency of solar power plants. Solar Energy. ISSN 0038-092X. 299. doi: 10.1016/j.solener.2025.113673. Full text in Research Archive Show summary

  Unmanned aerial vehicles (UAVs) inspecting solar photovoltaic (PV) power plants with infrared (IR) cameras is a well-established method to identify hotspots and other defects that radiate heat. With large PV power plants, the task of inspecting the entire area can be overwhelming if the equipment and planning are inadequate. With so much information in each image, the quality of the images will determine if the inspection is useful or not. In previous work, the uncertainty in UAV navigation system parameters has been analyzed and shown to seriously deteriorate image quality and affect inspection efficiency. However, in this study, the analysis is extended to include the effect of image blurring (called motion blur), resulting from the UAV travelling too fast, obscuring vital details in the video image. The novel analysis shows that motion blur is to be regarded as a key factor limiting data quality and data acquisition efficiency. Thus, a comprehensive PV inspection simulator that analyzes the effect of motion blur combined with the UAV navigation performance, is proposed to assess the complete system performance. The simulator is used to evaluate two levels of navigation precision and three camera setups at three different power plant latitudes. To avoid unacceptable motion blurring in the IR images, the maximum UAV flight velocity is determined for all cases. Subsequently, the maximum data acquisition rate of the overall system is calculated. The simulation results show that the design of a UAV system for PV power plant inspection should include a carefully chosen platform that balances navigation performance and image resolution. The image resolution directly affects the maximum flight velocity of the UAV, caused by motion blurring, thus constraining the inspection time and data acquisition rate.

• Morrison, Aiden James; Sokolova, Nadezda; Gerrard, Nicolai; Hauglin, Harald; Rødningen, Thomas & Rødningsby, Anders (2025). Making a Good Thing Better: Jammertest 2023 Jamming, Meaconing, Spoofing, and Synchronization on the Norwegian Coast. Engineering Proceedings. 88(1). doi: 10.3390/engproc2025088015. Full text in Research Archive Show summary

  Jammertest is the largest known GNSS jamming, meaconing, and spoofing test event in the world, which has an open policy towards both user participation and user communication with no restrictions on the sharing of data or publication of results. The organizers implemented several changes and enhancements within the 2023 test campaign to further broaden the appeal and applicability of the tests for as many demographics of GNSS users as possible. More than 200 participants from 19 nations took part in person from 18 to 22 September at the test sites along the west coast of the Andøy island. This paper summarizes the design and motivation of the tests and test venue with particular attention to the efforts taken to provide users with precision timing and frequency references independent of the denied and disrupted GNSS signals. Aspects of surveilling and enforcing unintentional emissions, and real-time communication and coordination to the large number of distributed participants are also discussed.

• Morrison, Aiden J; Sokolova, Nadezda; Solberg, Anders Martin; Gerrard, Nicolai; Rødningsby, Anders & Hauglin, Harald [Show all 8 contributors for this article] (2023). Jammertest 2022: Jamming and Spoofing Lessons Learned. Engineering Proceedings. 54(1). doi: 10.3390/ENC2023-15445. Full text in Research Archive Show summary

  Jammertest 2022 was a week-long series of satellite navigation and timing signal jamming and spoofing exercises carried out on the Norwegian island of Andøya in September of 2022. Organized via a collaboration between the Norwegian spectrum management authority, defense research establishment, public roads administration, metrology service, and others, the result was the largest known GNSS jamming and spoofing event open to international collaboration and provided an open-access data and publication policy for participants. This paper reviews the event’s organization, scheduled tests, noteworthy jamming observations, noteworthy spoofing observations, and the unexpected observations found during the event and also presents information on what data are publicly available to interested parties, along with the contact information needed to obtain these data.

• Morrison, Aiden J; Sokolova, Nadezda; Gerrard, Nicolai; Rødningsby, Anders; Rost, Christian & Ruotsalainen, Laura (2023). Radio-Frequency Interference Considerations for Utility of the Galileo E6 Signal Based on Long-Term Monitoring by ARFIDAAS. Navigation. ISSN 0028-1522. 70(1). doi: 10.33012/navi.560. Full text in Research Archive Show summary

  The extent to which navigation signals in the E6 band may be impacted by shared spectrum allocations might be underappreciated. This paper presents top-level observations from a multi-year international radio frequency interference (RFI) monitoring project covering all L-band global navigation satellite system (GNSS) signals with specific focus on the challenges facing the E6 band. The context of this paper is the assumption that most users will be non-authorized and have access to only the open data-bearing signal component and not the encrypted pilot of the E6 Galileo signal. In virtually all locations where the Advanced RFI Detection, Analysis, and Alerting System (ARFIDAAS) monitoring stations were deployed, frequent disruption of the E6 band from systems such as radar installations or other authorized users of the spectrum was observed. In the presented paper, an effort is made to put the observations in the context of the expected use cases of the E6 signal.

• Solend, Tor Atle; Moen, Hans Jonas Fossum & Rødningsby, Anders (2021). Modelling the impact of UAV navigation errors on infrared PV inspection data quality and efficiency. Conference record of the Photovoltaic Specialists Conference. ISSN 0160-8371. p. 991–996. doi: 10.1109/PVSC43889.2021.9518810. Full text in Research Archive
• Rødningsby, Anders; Bar-Shalom, Yaakov; Hallingstad, Oddvar & Glattetre, John (2009). Multitarget Multisensor Tracking in the Presence of Wakes. Journal of Advances in Information Fusion. ISSN 1557-6418. 4(2), p. 117–145. Full text in Research Archive
• Rødningsby, Anders & Bar-Shalom, Y (2009). Tracking of Divers using a Probabilistic Data Association Filter with a Bubble Model. IEEE Transactions on Aerospace and Electronic Systems. ISSN 0018-9251. 45(3), p. 1181–1193. doi: 10.1109/TAES.2009.5259192. Full text in Research Archive
• Rødningsby, Anders; Bar-Shalom, Yaakov; Hallingstad, Oddvar & Glattetre, John (2008). Multitarget Tracking in the Presence of Wakes, Proceedings of the 11th International Conference on Information Fusion. IEEE Press. ISSN 9783800730926. Full text in Research Archive
• Kåsen, Ingebjørg; Rødningsby, Anders; Haavardsholm, Trym Vegard & Skauli, Torbjørn (2008). Band selection for hyperspectral target-detection based on a multinormal mixture anomaly detection algorithm. Proceedings of SPIE, the International Society for Optical Engineering. ISSN 0277-786X. 6966. doi: 10.1117/12.777758. Full text in Research Archive
• Rødningsby, Anders & Bar-Shalom, Yaakov (2007). Tracking of Divers in a Noisy Background Using a Bubble Model. Proceedings of SPIE, the International Society for Optical Engineering. ISSN 0277-786X. 6699. doi: 10.1117/12.731629. Full text in Research Archive

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• Solend, Tor Atle; Moen, Hans Jonas Fossum & Rødningsby, Anders (2022). Positioning a UAV for Infrared Inspection of Several Rows of Solar Panels Simultaneously. Proceedings of the European Photovoltaic Solar Energy Conference. ISSN 2196-100X. Full text in Research Archive Show summary

  When photovoltaic (PV) solar panels in a PV power plant deteriorate after some time of operation, a thermographic inspection with unmanned aerial vehicles (UAVs) can be necessary. Often, faulty panels, or cells within panels, radiate heat that is visible with infrared (IR) cameras. When performing a thermographic inspection of solar panel faults from a UAV, the correct choice of position for the UAV depends on several factors. The camera's pixel resolution and field of view (FOV) set a distance threshold between the panel and the UAV according to a minimum resolution requirement. This threshold is also dependent on the angle between the panel and the UAV. Because of the vast size of some PV power plants, inspecting several rows of panels simultaneously is often appropriate. Latitude-dependent row-to-row distances limit the number of rows which fit inside the FOV which leads to site-dependent strategies. This paper analyzes several key factors, concerning the choice of position for a thermographic inspection of a solar PV power plant with a UAV.

• Solend, Tor Atle; Moen, Hans Jonas Fossum & Rødningsby, Anders (2022). Positioning a UAV for Infrared Inspection of Several Rows of Solar Panels Simultaneously. Full text in Research Archive
• Gerrard, Nicolai; Rødningsby, Anders; Morrison, Aiden J; Sokolova, Nadezda & Rost, Christian (2022). Exploration of Unintentional GNSS RFI Sources: Causes, Occurrence Rates, and Predicted Future Impact, Proceedings of the 35th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS+ 2022). Curran Associates, Inc.. ISSN 9780936406329. p. 3925–3934. doi: 10.33012/2022.18575. Full text in Research Archive Show summary

  This paper explores the typically ignored topic domain of unintentional GNSS RFI, as opposed to the more commonly documented maliciously generated RFI events, including jamming and spoofing. We begin by defining the numerous sources of unintentional RFI that have been encountered directly by the authors as well as those located through literature survey, then proceed to document examples of observations of the various families and source types of the unintentional RFI discussed. Based on the observations presented here, it is believed that unintentional RFI is presently a larger threat to L1/E1 band device operation than to the other GNSS frequency bands, but that trends in GNSS equipment itself may lead to the other GNSS frequency bands experiencing rapid increases in incidence rates of unintentional RFI over the coming decade.

• Rødningsby, Anders (2021). Monitorering av GNSS-forstyrrelser i veitrafikken - jamming eller utilsiktet støy? Full text in Research Archive
• Gerrard, Nicolai; Rødningsby, Anders; Morrison, Aiden J; Sokolova, Nadezda & Rost, Christian (2021). GNSS RFI Monitoring and Classification on Norwegian Highways – An Authority Perspective, Proceedings of the 34th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS+ 2021). Curran Associates, Inc.. ISSN 9780936406299. p. 864–878. doi: 10.33012/2021.17952. Full text in Research Archive Show summary

  This paper presents analysis and results from Global Navigation Satellite System (GNSS) radio frequency inter-ference (RFI) monitoring along one of the main Norwegian highways. Classification and analysis of GNSS RFI data from a period of 20 months is presented, where a simple correlation analysis is performed to understand RFI effects on some GNSS parameters. It is shown that the main type of GNSS RFI severely affecting GNSS receiv-ers are jammers, yet jammers are in no way the most prevalent cause for RFI observed. The data presented shows a continuation of trends described in earlier monitoring campaigns, with a slight increase of jammers in 2021. The paper also outlines how the results from a monitoring campaign like this could be used effectively in a strategy for spectrum enforcement efforts.

• Morrison, Aiden J; Sokolova, Nadezda; Gerrard, Nicolai; Rødningsby, Anders; Rost, Christian & Ruotsalainen, Laura (2021). RFI Considerations for Utility of the Galileo E6 Signal, Proceedings of the 34th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS+ 2021). Curran Associates, Inc.. ISSN 9780936406299. p. 2870–2878. doi: 10.33012/2021.18018. Full text in Research Archive Show summary

  While it is generally known that multi-frequency GNSS implies the coexistence of the satellite navigation signals with other users of the spectrum, the extent to which some of the signals may be impacted by shared spectrum allocations might be underappreciated. This paper presents top level observations from a multi-year international radio frequency interference (RFI) monitoring project covering all L-band signals with specific focus on the challenges facing the E6 band. The context of discussion of the RFI challenges to E6 and their potential mitigations is based on the assumption that most users will be non-authorized and have access to only the open data bearing signal component. In virtually all locations where the Advanced RFI Detection, Analysis and Alerting System (ARFIDAAS) monitoring stations were deployed, frequent disruption of the E6 band from systems such as RADARS or other authorized users of the spectrum was observed. In the presented paper, an effort is made to put the observations in the context of the expected use cases of the E6 signal, as well as the motivations of the other users of the spectrum and the options for coexistence from the point of view of the GNSS receiver.

• Rødningsby, Anders; Morrison, Aiden J; Sokolova, Nadezda; Gerrard, Nicolai & Rost, Christian (2020). RFI Monitoring of GNSS Signals on Norwegian Highways, Proceedings of the 33rd International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS+ 2020). Curran Associates, Inc.. ISSN 9780936406268. p. 3536–3549. Full text in Research Archive Show summary

  This paper presents the analysis and results from radio frequency interference (RFI) monitoring along main highways in Norway. The work started with an initial two months monitoring campaign in 2013, followed by a few shorter monitoring campaigns up through 2017. From January 2018 the system has been monitoring continuously, but the presented results cover only data up to the end of 2019. The extracted trend data show that the number of intentional jammers have increased from 2013 and up to 2018, but indicate a significant reduction in 2019. One potential reason for the reduction in 2019 can be that GPS jammers had a rising interest in the Norwegian media in the first quarter of 2019, leading to increased public awareness of the illegality of jamming and the potential to be caught if using jammers. The detections, including both intentional and non-intentional interference, are relatively equally distributed among the different vehicles, however the detections that are likely to originate from intentional GNSS jammers are mainly found in trucks and vans, often marked with a company logo.

• Rødningsby, Anders (2019). Forstyrrelse av GNSS - Jamming og spoofing. Full text in Research Archive
• Rødningsby, Anders (2016). Navigasjonskrigføring (NAVWAR) - NEMO 2016. Full text in Research Archive
• Rødningsby, Anders (2015). GPS Jamming ...og litt spoofing. Full text in Research Archive
• Rødningsby, Anders (2014). GPS Jamming - Skjer det i Norge? Full text in Research Archive
• Rødningsby, Anders; Bar-Shalom, Yaakov; Hallingstad, Oddvar & Glattetre, John (2008). Multitarget Tracking in the Presence of Wakes. Full text in Research Archive
• Rødningsby, Anders & Bar-Shalom, Yaakov (2007). Tracking of Divers in a Noisy Background Using a Bubble Model. Full text in Research Archive
• Hübert, Lily; Solend, Tor Atle; Rødningsby, Anders & Sellevåg, Stig Rune (2026). Posisjon, navigasjon og tid –og betydningen for totalforsvaret. Forsvarets forskningsinstitutt . Full text in Research Archive Show summary

  På oppdrag fra Nærings- og fiskeridepartementet har Forsvarets forskningsinstitutt vurdert betydningen satellittbasert posisjonsbestemmelse, navigasjon og tidsbestemmelse (PNT) har for totalforsvaret. Globale navigasjonssatellittsystemer (GNSS) har i økende grad blitt integrert i flere deler av samfunnet som en kilde til svært nøyaktig posisjon og tid. Samtidig er GNSS-signalene svake og svært sårbare for elektromagnetiske forstyrrelser, både naturlige og menneskeskapte. Slike forstyrrelser har funnet sted i Norge de siste årene, og Etterretningstjenesten vurderer i den åpne trusselvurderingen at verdensrommet kan være en fremtidig arena for krigføring. Hovedfokuset i rapporten er en vurdering av GNSS-avhengigheter, men romvirksomhet i stort er også diskutert. I denne studien kartlegger vi ulike bruksområder av GNSS i samfunnet og beskriver tilsiktede handlinger og farer som kan føre til bortfall av GNSS og andre satellitt-tjenester. Deretter vurderer vi betydningen GNSS har for totalforsvarsevnen basert på en risikoanalyse for kritiske samfunnsfunksjoner. Studien har identifisert sektorovergripende sårbarheter som øker risiko for totalforsvaret. Disse inkluderer den økende avhengigheten til GNSS og flere usikkerhetsmomenter knyttet til hvorvidt samfunnsfunksjoner kan motstå forstyrrelser i GNSS. Vi vurderer at satellittbasert PNT styrker totalforsvaret, og at GNSS-forstyrrelser vil redusere effektivitet og kapasitet i flere kritiske samfunnsfunksjoner sammenlignet med dagens tilstand. Bruk av feil tidsdata, som følge av stadig mer avanserte spoofing-angrep, øker risiko for tap av funksjonsevne, særlig i digitale og automatiserte systemer. Mangel eller feil på GNSS-signaler vil øke faren for tap av liv og helse, særlig knyttet til nødetatenes behov for PNT, og redusere situasjonsbevissthet i hele krisespekteret. Dette kan blant annet føre til farlige situasjoner for transporttjenester og forsinkelser i leveranser av forsyninger. GNSS-forstyrrelser kan skape problemer for kraftforsyningen og mobilnettet. Vi anbefaler seks risikoreduserende tiltak som vil øke PNT-motstandsdyktigheten i Norge: • tilrettelegge for og gjennomføre testing av utstyr for å identifisere og kartlegge sårbarheter • utvikle nasjonale rammeverk og retningslinjer for PNT og krav til samfunnssektorer for redundans • utvikle bakkebaserte alternativer for å ivareta en stabil tidsreferanse i Norge og Norges økonomiske sone • gjøre bruken av GNSS mer motstandsdyktig • utvikle robuste multi-sensor PNT-systemer • fortsette med internasjonalt samarbeid for å forbedre sikkerheten og tilgjengeligheten av satellittbasert PNT og andre satellitt-tjenester

• Rødningsby, Anders (2010). Multitarget Multisensor Trackingin the Presence of Wakes. Norges teknisk-naturvitenskapelige universitet. ISSN 9788247121573. Full text in Research Archive Show summary

  TARGET tracking is an essential requirement for surveillance and control systems to interpret the environment. This environment may contain multiple targets, and the environmental information may be obtained by multiple sensors in a multitarget multisensor tracking system. In this thesis we focus on targets which, in addition to reflecting signals themselves, also have a trailing path behind them, called a wake. This wake causes additional measurements to those originating from the target. When the measurements are processed, the estimated track can be misled and sometimes lose the real target because of the wake. This problem becomes even more severe in multitarget environments where targets are operating close to each other in the presence of wakes. In this thesis a probabilistic model is developed which reflects the probability that a false measurement originates from the wake behind a target. This wake model is integrated in the probabilistic data association filter (PDAF) to improve the track continuity for tracking single targets. The modified PDAF is further extended to handle multiple targets in the presence of wakes by using a probabilistic wake model for each of the targets in the multitarget environment that has a wake behind it. These single wake models are combined to form a joint wake model which augments the joint probabilistic data association filter (JPDAF) for both coupled and decoupled filtering. The wake-originated measurements may also cause confusion in the track initiation. To prevent this problem, a clustering method is proposed based on morphological operators which allows tracks to be initialized based on two-point differencing of the cluster centroids from succeeding scans. The modified PDAF is tested on data of a real scuba diver with an open breathing system. In this case the air bubbles produced by the diver form a wake which extends far behind the diver. The experiment showed that the above modifications of the PDAF improved the track continuity significantly. Finally, a relatively extensive simulation, based on real scuba diver data, is presented. Four different multitarget multisensor tracking scenarios are simulated, considering two targets with wakes that are: 1. Crossing each other. 2. Moving in parallel to each other. 3. One following after another. 4. Meeting and then passing each other. The results of these simulation scenarios show that the presented modifications improve the tracking performance, and the probability of lost tracks is significantly reduced. The targets are observed by two sensors, and it is shown that tracks estimated in a centralized fusion configuration are better than the local tracks estimated using data from individual sensors only. It is also shown that applying the wake model to targets that do not generate a wake, yields almost no deterioration of the tracking performance.

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