{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,12]],"date-time":"2026-02-12T17:04:24Z","timestamp":1770915864476,"version":"3.50.1"},"reference-count":46,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2021,12,6]],"date-time":"2021-12-06T00:00:00Z","timestamp":1638748800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000781","name":"European Research Council","doi-asserted-by":"publisher","award":["GA101002644 - BEE-MOVE"],"award-info":[{"award-number":["GA101002644 - BEE-MOVE"]}],"id":[{"id":"10.13039\/501100000781","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Centre Occitanie-Toulouse","award":["SIDIPAR"],"award-info":[{"award-number":["SIDIPAR"]}]},{"DOI":"10.13039\/501100001665","name":"Agence Nationale de la Recherche","doi-asserted-by":"publisher","award":["ANR-19-CE37-0024 \u2013 3DNaviBee"],"award-info":[{"award-number":["ANR-19-CE37-0024 \u2013 3DNaviBee"]}],"id":[{"id":"10.13039\/501100001665","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The automated quantification of the behaviour of freely moving animals is increasingly needed in applied ethology. State-of-the-art approaches often require tags to identify animals, high computational power for data collection and processing, and are sensitive to environmental conditions, which limits their large-scale utilization, for instance in genetic selection programs of animal breeding. Here we introduce a new automated tracking system based on millimetre-wave radars for real time robust and high precision monitoring of untagged animals. In contrast to conventional video tracking systems, radar tracking requires low processing power, is independent on light variations and has more accurate estimations of animal positions due to a lower misdetection rate. To validate our approach, we monitored the movements of 58 sheep in a standard indoor behavioural test used for assessing social motivation. We derived new estimators from the radar data that can be used to improve the behavioural phenotyping of the sheep. We then showed how radars can be used for movement tracking at larger spatial scales, in the field, by adjusting operating frequency and radiated electromagnetic power. Millimetre-wave radars thus hold considerable promises precision farming through high-throughput recording of the behaviour of untagged animals in different types of environments.<\/jats:p>","DOI":"10.3390\/s21238140","type":"journal-article","created":{"date-parts":[[2021,12,6]],"date-time":"2021-12-06T22:18:42Z","timestamp":1638829122000},"page":"8140","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["A Non-Invasive Millimetre-Wave Radar Sensor for Automated Behavioural Tracking in Precision Farming\u2014Application to Sheep Husbandry"],"prefix":"10.3390","volume":"21","author":[{"given":"Alexandre","family":"Dore","sequence":"first","affiliation":[{"name":"Laboratory for Analysis and Architecture of Systems, Toulouse University, CNRS, INPT, 31400 Toulouse, France"},{"name":"Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), CNRS, University Paul Sabatier-Toulouse III, 31400 Toulouse, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8308-9968","authenticated-orcid":false,"given":"Cristian","family":"Pasquaretta","sequence":"additional","affiliation":[{"name":"Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), CNRS, University Paul Sabatier-Toulouse III, 31400 Toulouse, France"}]},{"given":"Dominique","family":"Henry","sequence":"additional","affiliation":[{"name":"Laboratory for Analysis and Architecture of Systems, Toulouse University, CNRS, INPT, 31400 Toulouse, France"},{"name":"Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), CNRS, University Paul Sabatier-Toulouse III, 31400 Toulouse, France"}]},{"given":"Edmond","family":"Ricard","sequence":"additional","affiliation":[{"name":"GenPhySE, Toulouse University, INRAE, ENVT, 31326 Castanet Tolosan, France"}]},{"given":"Jean-Fran\u00e7ois","family":"Bompa","sequence":"additional","affiliation":[{"name":"GenPhySE, Toulouse University, INRAE, ENVT, 31326 Castanet Tolosan, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7004-8267","authenticated-orcid":false,"given":"Mathieu","family":"Bonneau","sequence":"additional","affiliation":[{"name":"URZ, INRAE, Petit-Bourg, 97170 Guadeloupe, France"}]},{"given":"Alain","family":"Boissy","sequence":"additional","affiliation":[{"name":"UMR Herbivores, Clermont University, INRAE, VetAgro Sup, 63122 Saint-Gen\u00e8s Champanelle, France"}]},{"given":"Dominique","family":"Hazard","sequence":"additional","affiliation":[{"name":"GenPhySE, Toulouse University, INRAE, ENVT, 31326 Castanet Tolosan, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2463-2040","authenticated-orcid":false,"given":"Mathieu","family":"Lihoreau","sequence":"additional","affiliation":[{"name":"Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), CNRS, University Paul Sabatier-Toulouse III, 31400 Toulouse, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6113-0648","authenticated-orcid":false,"given":"Herv\u00e9","family":"Aubert","sequence":"additional","affiliation":[{"name":"Laboratory for Analysis and Architecture of Systems, Toulouse University, CNRS, INPT, 31400 Toulouse, France"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"451","DOI":"10.1038\/nmeth.1328","article-title":"High-Throughput Ethomics in Large Groups of Drosophila","volume":"6","author":"Branson","year":"2009","journal-title":"Nat. Methods"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.neuron.2014.09.005","article-title":"Toward a Science of Computational Ethology","volume":"84","author":"Anderson","year":"2014","journal-title":"Neuron"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1038\/s41567-018-0093-0","article-title":"Ethology as a Physical Science","volume":"14","author":"Brown","year":"2018","journal-title":"Nat. Phys."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"367","DOI":"10.1111\/brv.12174","article-title":"Studying the Evolutionary Ecology of Cognition in the Wild: A Review of Practical and Conceptual Challenges","volume":"91","author":"Cole","year":"2016","journal-title":"Biol. Rev."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Huang, W., Pilkington, J.G., and Pemberton, J.M. (2021). Patterns of MHC-Dependent Sexual Selection in a Free-Living Population of Sheep. Mol. Ecol.","DOI":"10.1101\/2020.11.18.387332"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1017\/S1751731112001978","article-title":"Genetics of Behavioural Adaptation of Livestock to Farming Conditions","volume":"7","author":"Canario","year":"2013","journal-title":"Animal"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"805","DOI":"10.1017\/ASC200696","article-title":"Genetic Correlations between Temperament and Breeding Traits in Limousin Heifers","volume":"82","author":"Phocas","year":"2006","journal-title":"Anim. Sci."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"381","DOI":"10.1186\/1297-9686-37-5-381","article-title":"Genetic Analysis of Emotional Reactivity in Sheep: Effects of the Genotypes of the Lambs and of Their Dams","volume":"37","author":"Boissy","year":"2005","journal-title":"Genet. Sel. Evol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2163","DOI":"10.1098\/rstb.2010.0090","article-title":"Global Positioning System and Associated Technologies in Animal Behaviour and Ecological Research","volume":"365","author":"Tomkiewicz","year":"2010","journal-title":"Philos. Trans. R. Soc. B Biol. Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"923","DOI":"10.1007\/s10344-010-0391-z","article-title":"Satellite Telemetry Reveals Individual Variation in Juvenile Bonelli\u2019s Eagle Dispersal Areas","volume":"56","author":"Urios","year":"2010","journal-title":"Eur. J. Wildl. Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"380","DOI":"10.1016\/j.compag.2009.07.009","article-title":"A Complete Farm Management System Based on Animal Identification Using RFID Technology","volume":"70","author":"Voulodimos","year":"2010","journal-title":"Comput. Electron. Agric."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1038\/379029b0","article-title":"Tracking Bees with Harmonic Radar","volume":"379","author":"Riley","year":"1996","journal-title":"Nature"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"743","DOI":"10.1038\/nmeth.2994","article-title":"IdTracker: Tracking Individuals in a Group by Automatic Identification of Unmarked Animals","volume":"11","author":"Hinz","year":"2014","journal-title":"Nat. Methods"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1016\/j.jpdc.2019.07.007","article-title":"Estimation of Energy Consumption in Machine Learning","volume":"134","author":"Rodrigues","year":"2019","journal-title":"J. Parallel Distrib. Comput."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"417","DOI":"10.1016\/j.tree.2014.05.004","article-title":"Automated Image-Based Tracking and Its Application in Ecology","volume":"29","author":"Dell","year":"2014","journal-title":"Trends Ecol. Evol."},{"key":"ref_16","unstructured":"Dore, A., Lihoreau, M., Billon, Y., Ravon, L., Bailly, J., Bompa, J.-F., Ricard, E., Aubert, H., Henry, D., and Canario, L. (2020, January 17). Millimetre-Wave Radars for the Automatic Recording of Sow Postural Activity. Proceedings of the 71. Annual Meeting of the European Association for Animal Production (EAAP), Porto, Portugal."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Dore, A., Henry, D., Lihoreau, M., and Aubert, H. (2020, January 5\u201310). 3D Trajectories of Multiple Untagged Flying Insects from Millimetre-Wave Beamscanning Radar. Proceedings of the 2020 IEEE International Symposium on Antennas and Propagation and North American Radio Science Meeting, Montr\u00e9al, QC, Canada.","DOI":"10.1109\/IEEECONF35879.2020.9329732"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"151","DOI":"10.2528\/PIERM18040404","article-title":"Automated Monitoring of Livestock Behavior Using Frequency-Modulated Continuous-Wave Radars","volume":"69","author":"Henry","year":"2018","journal-title":"Prog. Electromagn. Res."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Hazard, D., Moreno, C., Foulqui\u00e9, D., Delval, E., Fran\u00e7ois, D., Bouix, J., Sall\u00e9, G., and Boissy, A. (2014). Identification of QTLs for Behavioral Reactivity to Social Separation and Humans in Sheep Using the OvineSNP50 BeadChip. BMC Genom., 15.","DOI":"10.1186\/1471-2164-15-778"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1459","DOI":"10.2527\/jas.2015-0277","article-title":"Genotype by Environment Interactions for Behavioral Reactivity in Sheep","volume":"94","author":"Hazard","year":"2016","journal-title":"J. Anim. Sci."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/j.applanim.2011.09.004","article-title":"Assessment of Sociability in Farm Animals: The Use of Arena Test in Lambs","volume":"135","author":"Ligout","year":"2011","journal-title":"Appl. Anim. Behav. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Haderer, A., Wagner, C., Feger, R., and Stelzer, A. (2008, January 21\u201323). A 77-GHz FMCW Front-End with FPGA and DSP Support. Proceedings of the 2008 International Radar Symposium, Wroclaw, Poland.","DOI":"10.1109\/IRS.2008.4585708"},{"key":"ref_23","unstructured":"Redmon, J., and Farhadi, A. (2018). Yolov3: An Incremental Improvement. arXiv."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1007\/s11263-014-0733-5","article-title":"The Pascal Visual Object Classes Challenge: A Retrospective","volume":"111","author":"Everingham","year":"2015","journal-title":"Int. J. Comput. Vis."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"105150","DOI":"10.1016\/j.compag.2019.105150","article-title":"Outdoor Animal Tracking Combining Neural Network and Time-Lapse Cameras","volume":"168","author":"Bonneau","year":"2020","journal-title":"Comput. Electron. Agric."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"69480E","DOI":"10.1117\/12.784598","article-title":"Absorption, Transmission, and Scattering of Expanded Polystyrene at Millimeter-Wave and Terahertz Frequencies","volume":"Volume 6948","author":"Dietlein","year":"2008","journal-title":"Proceedings of the Passive Millimeter-Wave Imaging Technology XI"},{"key":"ref_27","unstructured":"Balanis, C.A. (2011). Modern Antenna Handbook, John Wiley & Sons."},{"key":"ref_28","first-page":"659","article-title":"Gaussian Mixture Models","volume":"741","author":"Reynolds","year":"2009","journal-title":"Encycl. Biom."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Burnham, K.P. (1998). Model Selection and Multimodel Inference. A Practical Information-Theoretic Approach, Springer.","DOI":"10.1007\/978-1-4757-2917-7_3"},{"key":"ref_30","first-page":"2825","article-title":"Scikit-Learn: Machine Learning in Python","volume":"12","author":"Pedregosa","year":"2011","journal-title":"J. Mach. Learn. Res."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Simon, W., Klein, T., and Litschke, O. (2014, January 6\u201311). Small and Light 24 GHz Multi-Channel Radar. Proceedings of the 2014 IEEE Antennas and Propagation Society International Symposium (APSURSI), Memphis, TN, USA.","DOI":"10.1109\/APS.2014.6904821"},{"key":"ref_32","unstructured":"Ryan, H. (1994). Ricker, Ormsby; Klander, Bntterwo-A Choice of Wavelets, CSEG Recorder."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2130","DOI":"10.1109\/TAP.2009.2016702","article-title":"Lacunarity of Rough Surfaces from the Wavelet Analysis of Scattering Data","volume":"57","author":"Poirier","year":"2009","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_34","first-page":"69","article-title":"Wavelet Analysis to Detect Regime Shifts in Animal Movement","volume":"1","author":"Gaucherel","year":"2011","journal-title":"Comput. Ecol. Softw."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"106","DOI":"10.3389\/fnbeh.2016.00106","article-title":"Analysis of Individual Mouse Activity in Group Housed Animals of Different Inbred Strains Using a Novel Automated Home Cage Analysis System","volume":"10","author":"Bains","year":"2016","journal-title":"Front. Behav. Neurosci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1276","DOI":"10.1017\/S1751731111000292","article-title":"Is the Establishment Rate and Fecundity of Haemonchus Contortus Related to Body or Abomasal Measurements in Sheep?","volume":"5","author":"Idris","year":"2011","journal-title":"Animal"},{"key":"ref_37","unstructured":"Team, R.C. (2014). R: A Language and Environment for Statistical Computing, R Foundation for Statistical Computing."},{"key":"ref_38","unstructured":"Stroup, W.W. (2012). Generalized Linear Mixed Models: Modern Concepts, Methods and Applications, CRC Press."},{"key":"ref_39","first-page":"1","article-title":"FactoMineR: An R Package for Multivariate Analysis","volume":"25","author":"Josse","year":"2008","journal-title":"J. Stat. Softw."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"855","DOI":"10.2466\/pr0.1991.68.3.855","article-title":"Coefficient Alpha for a Principal Component and the Kaiser-Guttman Rule","volume":"68","author":"Kaiser","year":"1991","journal-title":"Psychol. Rep."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1002\/j.2161-4296.1995.tb01894.x","article-title":"A Low-Power Postprocessed DGPS System for Logging the Locations of Sheep on Hill Pastures","volume":"42","author":"Roberts","year":"1995","journal-title":"Navigation"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"375","DOI":"10.1002\/dev.20218","article-title":"Establishment of Vocal Communication and Discrimination between Ewes and Their Lamb in the First Two Days after Parturition","volume":"49","author":"Sebe","year":"2007","journal-title":"Dev. Psychobiol. J. Int. Soc. Dev. Psychobiol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1163\/156853904322981905","article-title":"Vocal Discrimination of Kin and Non-Kin Agemates among Lambs","volume":"141","author":"Sebe","year":"2004","journal-title":"Behaviour"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"12729","DOI":"10.1073\/pnas.1503749112","article-title":"Intermittent Collective Dynamics Emerge from Conflicting Imperatives in Sheep Herds","volume":"112","author":"Ginelli","year":"2015","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Huang, H., Gui, G., Sari, H., and Adachi, F. (2018, January 27\u201330). Deep Learning for Super-Resolution DOA Estimation in Massive MIMO Systems. Proceedings of the 2018 IEEE 88th Vehicular Technology Conference (VTC-Fall), Chicago, IL, USA.","DOI":"10.1109\/VTCFall.2018.8691023"},{"key":"ref_46","unstructured":"Lui, H.-S., and Shuley, N. (2006, January 9\u201314). Resonance Based Radar Target Identification with Multiple Polarizations. Proceedings of the 2006 IEEE Antennas and Propagation Society International Symposium, Albuquerque, NM, USA."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/23\/8140\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:40:09Z","timestamp":1760168409000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/23\/8140"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,12,6]]},"references-count":46,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2021,12]]}},"alternative-id":["s21238140"],"URL":"https:\/\/doi.org\/10.3390\/s21238140","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,12,6]]}}}