Abstract
The new and more powerful R.A.F. 10 cm radar sets frequently detect ‘angels’ to ranges exceeeding 60 miles from the station. The seasons and times of day of their occurrence, their speed in relation to the wind, their directions of movement, and the influence of the weather, all fit the view that such echoes come from migrating birds, especially passerine birds. At a Norfolk station, the heaviest activity occurred eastwards in March and April, with a peak around 22.00 h G.M.T., and west-south-west in October and November, with peaks around 22.00 h and 10.00 h G.M.T.
Reference12 articles.
1. H a rp e r W . G. 1957 Nature Lond. 180 847.
2. Jo n e s R . F . 1952 Meteorological Research Papers no. 741 A ir M in istry L o n d o n .
3. L a c k D . & V arley G. C. 1945 Nature Lond. 156 446.
4. L o w ery G. H . 1951 Puhl. M us.N at. H ist. Univ. K ans. 3 361-472.
5. P la n k V. G. 1956 Geophysical Research Papers no. 52 A ir F o rc e C am bridge. R e search C e n te r B e d fo rd M ass.
Cited by
11 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献