?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F35%2F&rft.title=National+Air+Traffic+Services&rft.creator=Budd%2C+Chris&rft.creator=Hill%2C+Andrew&rft.creator=Andre+Leger%2C+Andre&rft.subject=Transport+and+Automotive&rft.subject=Aerospace+and+defence&rft.subject=Information+and+communication+technology&rft.description=National+Air+Traffic+Services+(NATS)+are+concerned+with+ensuring+low+probabilities+of+errors+in+determining+aircraft+positions.+In+general%2C+error+probabilities+depend+on+the+tails+of+some+probability+distributions+for+which+there+has+been+no+theoretical+model.+Analysis+of+radar+performance+is+regularly+undertaken+by+NATS+to+ensure+radar+performance+is+within+safety+limits%2C+with+the+maximum+range+being+dependent+on+the+declared+separation+between+aircraft.+NATS+brought+two+questions+to+the+Study+Group%2C+involving+the+horizontal+(azimuthal)+errors+in+radar+data+and+the+vertical+errors+in+altimetry+system+data.+In+both+cases%2C+NATS+asked+the+Study+Group+to+analyse+the+data+and+assess+whether+the+probability+distributions+that+are+currently+used+are+good+models+for+the+errors.&rft.date=2004-11-23&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F35%2F1%2FNATS.pdf&rft.identifier=++Budd%2C+Chris+and+Hill%2C+Andrew+and+Andre+Leger%2C+Andre++(2004)+National+Air+Traffic+Services.++%5BStudy+Group+Report%5D+++++&rft.relation=http%3A%2F%2Fwww.smithinst.ac.uk%2FProjects%2FESGI49%2FESGI49-NATS%2FReport%2FNATS.pdf