美軍擬在台灣部署薩德系統疑雲 (posted again)

choi

I posted it on Feb 14. But this website stopped at the Latin letter (lower case) "tau." I tried it again the next day, and no luck.  "Bridged" doe snot know why. So I am posting it again, but spelled out the Latin letter.  This is what lower-case tau looks like.
https://en.wikipedia.org/wiki/Tau
(table, on the right)

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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).
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
http://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
http://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.
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
http://en.wikipedia.org/wiki/Radar_signal_characteristics
(section 1.2 Pulse width: "The pulse width (tau) (or pulse duration) of the transmitted signal")

It is poorly written, so you need not read it. Just view the diagram.

It is important to know that "pulse width" is a duration of time, measured in microseconds. That is pulse width is how long the pulse is emitted, having nothing to do with wavelength (whose unit is nanometer) per se, but rather a multiple 倍数 of wavelength always. See next.
(B) A similar diagram appears in

Perry Sprawls PhD, Ultrasound Production and Interactions. undated.
www.sprawls.org/ppmi2/USPRO/

Here view two diagrams only:
* The first has the caption "The Temporal and Length Characteristics of an Ultrasound Pulse," where you can discern "wavelength" and "pulse duration."
* The second has the caption "The Temporal and Spatial Characteristics of Ultrasound Pulses That Affect Intensity Values."
(v)
(A) PAVE PAWS
http://en.wikipedia.org/wiki/PAVE_PAWS

Quote: "The radar operates in the UHF band between 420 - 450 MHz, just below the UHF television broadcast band, that is a wavelength of 71-67 cm, with circular polarization. It is an active array (AESA); each of the 1,792 transmitting elements has its own solid-state transmitter/receiver module, and radiates a peak power of 320 W, so the peak power of each array is 580 kW. It operates in a repeating 54 millisecond cycle in which it transmits a series of pulses, then listens for echoes. Its duty cycle (fraction of time spent transmitting) is never greater than 25% (so the average power of the beam never exceeds 25% of 540 kW, or 145 kW) and is usually around 18%. It is reported to have a range of about 3000 nautical miles (2608 statute miles, 5550 km); at that range it can detect an object the size of a small car, and smaller objects at closer ranges.
(B) https://en.wikipedia.org/wiki/Radar
(section 5.2 Frequency bands: table)

table:
Band name ............................Wavelength range .........Notes
UHF [ultra high frequency] .....0.3 - 1 m ......................Very long range (eg ballistic missile early warning)
X ...........................................2.5–3.75 cm .................Missile guidance * * * Named X band because the frequency was a secret during WW2.

(vi) Army Navy /Transportable Radar Surveillance (AN/TPY-2). Raytheon, undated.
www.raytheon.com/capabilities/products/antpy2/
(A) Search images.google.com with AN/TPY-2, and you will know what "transportable" means.
(B) What US has told China is: Don't worry. The range of AN/TPY-2 in terminal mode (TM) is quite short -- relative to in forward-based mode (FBM) -- and therefore won't see much of China.  However China counters that the two modes can be switched back and forth, the lag time being hours to make the transition).


(b) "曾任職於美國《防務新聞》（Defense News）、現為Shephard軍事網站記者顏文德（Wendell Minnick）撰文表示：台灣有意購入一百五十架傳統起降的F-35A與六十架垂直╱短場起降的F-35B匿蹤戰機"

Wendell Minnick, Ten Recommendations for Taiwan-US Mil[itary] Relations. London: Shephard Media, Jan 30, 2017
www.shephardmedia.com/news/defen ... military-relations/

the penultimate paragraph: "One is the prospect that Taiwan will request procurement of the F-35 fighter. Taiwanese military sources indicate that the air force will soon have a requirement to procure 60 F-35B short take-off/vertical landing fighters and 150 F-35A conventional fighters to replace ageing Mirage 2000s, Indigenous Defence Fighters and F-5 Tigers

There is no need to read the rest.
(c) "幾個星期前美國智庫「戰略暨預算評估中心」（CSBA）發表了最新的研究報告：《加強前線：美國國防戰略和中國的崛起》（Reinforcing the Front Line: U.S. Defense Strategy and the Rise of China）"

Center for Strategic and Budgetary Assessments
http://en.wikipedia.org/wiki/Cen ... dgetary_Assessments

(d) "二零零六年七月北韓試射「大浦洞二號」（Taepodong-2）洲際彈道飛彈（Intercontinental ballistic missile, ICBM）後，日本即引進了一組用於薩德系統的X頻段AN/TPY-2機動長程預警雷達系統，部署於青森縣津輕市航空自衛隊車力分屯基地，進行實驗測試。"
(i) Tsugaru, Aomori  
http://en.wikipedia.org/wiki/Tsugaru,_Aomori
(ii) In Japanese, it is written in hiragana (not kanji): つがる市. The ja.wikipedia.org says it was formed in 2005 through merger of various towns of 西津軽郡.