本帖最后由 choi 于 2-15-2017 08:52 编辑
呂禮詩, 美軍擬在台灣部署薩德系統疑雲. 亞洲週刊, Feb 19, 2017 (print date; his is not a blog).
http://www.yzzk.com/cfm/blogger3.cfm?id=1486611746541
Note:
(a) "盱衡台灣的地理位置,部署於江西贛州、福建永安、仙遊及漳州,與廣東梅州的彈道飛彈部隊,若以關島為目標,距離最短的「大圓航線」(Great Circle)都將越過台灣新竹、苗栗、台中及南投的空域;雖然樂山陣地已部署「鋪爪式」(PAVE PAWS)長程預警雷達,但其使用的UHF波段較薩德AN/TPY-2雷達使用X波段的解析度低。"
(i) Latitudes of Taiwan and Guam are, respectively, 21.9-25.3°N and 13.2-13.7°N. The air distance between Taipei and Guam is 1,703 miles or 2,741 km.
(ii) great circle
https://en.wikipedia.org/wiki/Great_circle
("This article is about the mathematical notion. For its applications in geodesy, see great-circle distance")
(iii)
(A) radar
https://en.wikipedia.org/wiki/Radar
(The information provided by radar includes the bearing [ie, coordinates] and range (and therefore position) of the object from the radar scanner
(B) Range Resolution. Radar Tutorial, undated.
http://www.radartutorial.eu/01.basics/Range%20Resolution.en.html
There are different radars for various goals. What matters here is distinction between "search radar" (such as PAVE PAWS) and "weapons-control radar" (such as THAAD radar). The problem with the author 呂禮詩 is that, like many others (Americans and Taiwanese alike), the author aims to make Taiwan less militarily strong than it is, to make excuses for arms sales between Taiwan and US.
(iv) The preceding (iii)(B) talks about
(A) radar signal characteristics
https://en.wikipedia.org/wiki/Radar_signal_characteristics
(section 1.2 Pulse width: "The pulse width ( |