免费观看特别黄大片

Friday, May 25, 2012

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???? ??????? ?????????????????????????????Radar cross-section (RCS) ?????? ???????????????????... Radar cross-section ???????????????????????? ????????????????? signal ?? ????? ???????????????? ?????????????????????? ??????????????????????
??????????????.... ????????? Radar cross-section ??????????????? ??????? ?????????????? ?????????????????????????... ??????????????signal ??? ????? ????????????????????????????...  ????????? signal ??? ????? ?????????????? ????????????? ???????????? ??? detect ???????????????????.. ?????? ?????????????????? ?????????????? ????????????????????????????...?????????????????????????? ???????????????  reflectedsignal power ??????????????????????????????????...
????????????????????????Radar cross-section ????????????????????? signal ??????????? ??????? (????) ?????????????????????? material ??????????? signal ??????????? incident angle ?signal ??????????? ????? ???????????? ????????????????????... ?????? ?????????????????????? ???  Radar cross-section  ????????????????? material ??????????????????????...?????????????????????? ?????? (signal ??????????????????) ??? ?????????? Radar cross-section ?????????????????? ?????????????????????...????????????? ??????????????? signal ??? ???????? ????????????????? ???????????...signal ??????????? ???????????????????????????????????????.... ????????? ???????
???????????? ???????? ?????detect ???????????????????????? ?????????????????... 
Northrop Grumman B-2 Spirit ???????????????????????????...


?????? ????????????????????????????????????????????? ?????????????? ??? ??????????????? ????????????????????... 
?????????????????????? ??????????????????????????????????? ??????????????... ???????? ?????????????????? ??????????????? ???????????????????????????????
???????????????? ???????????????????????????????????.... ????????????????????? ????????????? data sharing??????????? ???????????????????? operation ???????????? ???????????? ???????????????????????????....????????????????????????? ???? ?????????????????????????.. ???????????????????????????????????????????????????
??????????????????????????????????????????????????????????????.... ??????????????????????????? (demand) ????.. ???????????????????? ???????? speed ????????????? ????????????????????????????????????????????????????????????....
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???? ?? ???? ???????????? ???????????????????? ??????????????? ??????????????????? ???????????? ???????????????? ????????????????? ??????????????????? ????????????????????????????????

avionics ??....

??????????????????? ???????????????????????????? ????????????????? ???????????????????????????????????????????????????????? ?????????? system ???? method ????????????????????????????????????????????????????????????????????????????? ?? method ??????????????????????????????????? ??????????demand ???????????? ??????????????????? ???????????? ??????????????????????? ?????????????????????? ?????????? ??????????????????????????????????????????????????????...???? ?????????????????????????????????? ???? ???????? ??????????????????... ???????????? ?????????????? ????????????????? ?????????...?????????????????????????????????.... GPS ????????? ??????????????????? ????????????????????????????????....???????????????????????? ??????????????????? ???????? ???????? ????????????????? ??????????????????  ????????????????????????????????????????????...?????????????????? ???????????????????????????????????????...?????????????????????????? ??????????????? ??????????????? ???????????????????????????????? ??????... ??????? ?????????????????????? ???????????? ??????... ???????????????...?????? ?????  ?????????????????????????????? ?????????? ??????????? ?????? ??????????????????? ?????????????????????? ?????????????????????????...

Friday, March 30, 2012

Radio wave frequency & wavelength

?? ????????????????????? AC current ????????????????? ???????????????????? ? ????????? Wireless technology ????????????????? ????????? ????????? ?????????? ????????????????????????? ?????????????? electromagnetic radiation (EM) ??????????????? EM radiation ?? ?????????????????????????????? ????? 300,000,000 meters per second (186,000 miles per second) ????????????????? ????????????? ????????????????? EM wave ?????? frequency ???????????????????? electromagnetic radiation ?????? frequency ????? ????????????? ????????????????? ????????? metric prefixes ??????????? ???????????????? ???? -kilohertz (kHz): 1,000 hertz ? megahertz (MHz): 1,000,000 hertz ? gigahertz (GHz): 1,000,000,000 hertz ? EM radiation ??? frequency range ???????????? electromagnetic spectrum ?????????????? Radio waves ?? ?? spectrum ??? ???????????????????????????? ?????????????? 1 kHz ??? 300 GHz ????????? radio waves region ????????????????? 300 GHz ??????? infrared ray region ? ?????????? visible light ? ultraviolet ? X-ray? gamma ray ??????? ?????????????????????????? ??? - ????????????


???(?)
??????????????????????????????? radio waves ????? ????????????????????? visible light ??? ??????????????? frequency ??????????????????? ?????? EM waves ????? sound waves ?????????? ?????????????? ???????????????? sound waves ???? mechanical wave ???????????????????? ?????????????? ??????????????? ??????????????????? EM waves ???????? ??????????????? ??????? ??????????????????? sound waves ?? EM waves ????????????????????????? ?????????????????? ?????????????
?? ???????????????????????????????? EM waves ??????????? ????? radio waves ??????????? ????????????? radio waves ?????? wavelength ??????????????? ?????????? ????????????? frequency ???????????????????????? wavelength ??? frequency ????????????????????????????????
wavelength=wave propagation speed / frequency
EM radiation ??? ???????????????? ??????????????????????????????? ???????????????????????????? frequency ?????????????? ??????? wavelength ?????? ???????? ???????????????????????????? Frequency ??? wavelength ?? ????????????????? ????????? ???????????? ????????????????????? ?????????????????????????? ??????????????????????? ?????????????????????????????? ????????????? Frequency ?????????? ???????????????? ???????????? wavelength ????????? ???????????? ?????? ????????????? frequency / wavelength ranges ?????? bands ??????? ?????????????????????? International Telecommunications Union (ITU) ??? radio waves ?????? ?????????????? frequency bands ??????????????????????????



Frequency bands ???????????????? ??????????????????? NATO band ???????????? ????? bands ??????????? A ??? M ???????????????????????????? ??????????????????? ITU ?????????????? traditional band schemes ??? NATO band scheme ?? ????????????? ???? ?????????????????? ???????? NATO band ??????????????????????


NATO band ?? ??????? ??????? ??????????????????????????????? ???????? publications ?????? NATO band ??? ??????? traditional band ??????????????????? ????????? ??????????????????????????????? ????????????? "C", "L", ??? "K" bands ????? ??????????????? ??? schemes ??? ???????? ???????? ????????????????????????? ???????????????????? ????????????????????? ????????????????? ???????????? traditional band schemes ??????????????????????????????


Friday, March 18, 2011

Distribution law or distribution function

?????????????????????? ????????????????????????? ?????????????? function ????? ???????? ?????????????????? random process ??? limit ??????????????????? ????????????????????????????? ??????????? ???????????? ??????? function ????????????? graph ???????????????????????? ????? equation ??????????????? ????????????????????????????? ???????? ?????????????????? F(x) ??? distribution function ?????????????????????? ???????? ????????????? X ? random process ??? x ? ???? ???????? ???????????? ????? ????????????????? coordinate ?????????????????? argument ??????????????????????? P(X) ?? X ??? ???????????? (????) ????????????????? ????????????? argument x ?????????? random process X ??? ??????????????? distribution function ???? ?????????????? ?????????????????? ?????????????????? discrete random variable ?????????? distribution function ??? ???????????????????????????????????? ??? (?) ??? discrete random variable ?????????? ???????????????????????????

????????????????????? ???????? distribution function F(x) ?? ????????? ??????????? ????? x1 ????????? argument ???????????? ???????????? argument ?????? ????????????? ???????????? distribution function ????? ????????? ??????????????? ??????????????? F(x) ?? x1 ??? x2 ????????????????????? x1 ??????????????????? x1 ????????? argument ?????? ?????????????????
?? function ??? ????????????????? ??????????????
  • ?? ?????????????? distribution function ?? ???????????? argument ????????? argument ?????? ?????????????????????????????????????? negative infinity ????????? argument ?????? ????????????????????????? ?????? ???????????????
  • ?? ????? x2 ?? x1 ????????????????????? x2 ??? distribution function ?? x1 ??? distribution function ??????? ??????????? distribution function ???? ???????????? argument ????????? argument ?????? ????????????????????????????????? ???????????????????
  • ?? ????????? infinity ?????????? argument ??????? ????????? argument ???????????????? ????????? argument ?????????? ??????????????????? argument ?????????? ??????????????????????? ? ??????????
??? (?) ??????????????? probability distribution ??? ??? (?) ??? distribution function ?????? ???????????????

Monday, January 3, 2011

General requirements of measurement accuracy of height and aircraft vertical speed

Height ??? Vertical speed ??????????? equipment ?? ?????????? aircraft ?????? ????????? ??????????????? ??????????????????????? ???? equipment ??? ????????????? altimeter ???????????? problem ???????????????????????
  • ?? ?????? ????????? ???????????????? ???????????????? ??????????????????????? ??????????????????????????
  • ?? ???????????????????????? ???????? ????????? ?????????????? ??????????????
  • ?? ?????????????????????? ????????????? ?????????????????? soft landing ???????????? ???????????????????????????
  • ?? ???????????????? ????????????????????????????????? ???????????????????? ????? ?????????????? ???????????????????????????
  • ?? Satellite ????????? ??????????? ???????????????????????
  • ?? ????????????????????????????????????????? ????????????????????

免费观看特别黄大片Altimeter ?????????????????????????? problem ????????????????????? ?????? assignment ???? problem ???????????????

免费观看特别黄大片????????????? orientation ????? tactical problem ??????????????? altimeter ???????? ???????????????? ???????? ?????????????????? ????????????????????? ??????????????????????? level ? ????????? ?????? ??????????????????? altimeter ????????????????????????????????

?? ???????????? ?????????????? ????????????????????????????????????? ??????????????????? ????? soft landing ????????????? ????????????????????????? altimeter ??????????? ???????????????? ???????????????? ???????????????? high-altitude radio altimeter (75-10km)? low-altitude radio altimeter (12km-3m)?

Satellites ??????? altimeter ?????????? ????? geoid ?????????????????? ???????? geophysical study ??????????????? ????????????????? ????? global geoid ???????????????????? measurement accuracy ??? 5 m ?????????????? altimeter ?????????????????????? measurement accuracy ??? 1 m ??????????????????????

Altimeter ?????? ??????????? factor ???????? height measurement accuracy and aircraft vertical speed ???????????? aircraft ?????? class ??????????? ?????????????? ????????? accuracy ??????????????????????? ????????????????????????? ???????? ??????????????????????????? ????????? altimeter ??????????????????? ????????????? ???????????????????????????? ?????? aircraft ????????????????????? accuracy ????????????????????????????????????????????????????????? ????????????? altimeter ????? ?????????????????????? ?????????????????? signal ???????????????????????? ??????????? Height ??? Vertical speed ?????????????? ???????????????? random character ????????? ??????????????? measurement accuracy ??? “ ? “ ??????????????? ???????????? P(?) = 0.95 ?????????????? ???????? measurement error ? Gaussian distribution ?????????????????????????? measurement accuracy ?? ? = 2 sigma???? . sigma - one-sigma value. Table 1.1 ??? ????????? aircraft ?????? measurement error ???????????????? technical characteristic ????????????????????

Requirements of measurement accuracy ?? ??????????????????????????? ????? ?????????????????????? ?????????????? ????????? requirements of measurement accuracy of height and aircraft vertical speed ????????????????????????????? ???????? safety ???????? mass ??????????????? ?????????? ??????? ????????????????????????????????????????? ??????? measurement accuracy ?????????????????? ??????????????????? parameter ??????????????? ???????????? aircraft ?????? angle of roll ??? dip angle, pitch angle ???????????????? ????????????????????????? aircraft ??? ???????????????? ???????????????????? ????????????? ?????????????????????????????? typical altimeter ?????????? angle of roll ??-?? ????? ??? dip angle, pitch angle ?? ???????? ?????????????? ?????????????????????????????????? ????????? error ?????? ???????????????????????????????????? ????????????????????????????? error ?????? gyro stabilization antenna assembly ?????????????????????????? ???????????? aircraft ?????????????????? ???????????????????? radio beam ???????????????????????????????????????? (antenna ????????????????) ???????????????????????????????????????????? measurement accuracy ????????????????????? ?????????? ??????????????? ????????????????????????????? ??????????????? space system ????????????????????????????? ?????????? ???????????????????????? wide diagram ?????? antenna ????????????????????????? measurement accuracy ?????????????????????

Table 1.1

Monday, March 1, 2010

Radar gun (or) speed gun

?????????????????????????? ???????????????????????????? ??????????? ????? ???????????? ?????????? Radar gun ????? Doppler radar ?????????????????????? ?????? ????????????? ???????? ???????????? ? ?????????? ?????????????? ??????????? ??????????? ???????? ??????????? ?????????? ???????? ????????? ????? ???? ????????????? ????????? ???????? ???????????????? ????????????????? ?????????????? Radar gun ?? ?????????? ??????? ??????????????????? ????????????????????????? ??????? (????) ????? ?????????? ????????????? Radar gun ?????? ??????????????? ????????????????????????? ????????? ??? ???? ????????????????????????????????? ????????????????? ??????????????? Radar gun ?????? X band (8 to 12 GHz), K band (18 to 26.5 GHz), Ku band (12 to 18GHz), Ka band (26.5 to 40 GHz),IR Band (infrared) ????????????????????? Radar gun ??? ???????????? Bryce K.Brown ? ???? ?????? ??????? ??????????????????? Chicago ???????? ????????????????????? ?????????????????? ??????????????? ?????? radio transmitter ??? receiver ??????????? transmitter ??? radio signal ???????????????? receiver ????????? signal ??? ???????????????? ???????????? Doppler effect ??????? ?? frequency ???????? ???????????? ?????????? ???????????????? ?????????? ???????????????????????? ?????????? ??????????????????? ??????????????????????????????? Traffic ??????????? Radar gun ????? ?????????????????????????????? ????????????????????????????????????????? ??????????????????????? ????????? ???????? ?????????? ???????????????????? ??????????? ??????????? ???????????????? ??????????????? ????????????????????? ??????????????? ????????? ?????????? ?????????????????? ???????????????????? ???????????????????????????? ????????? antenna ????? ????????? ???????????????????? ?????????????????? ????????????????????? ????????? ?????????? ???????????????????????????????????? ????????????????????? ?????????????? ???????????? ??????????????????????????????? ??????????????????????????? ??????????????????? ????????? ?????????????? ???????????????? ?????????????????????? ??????????????????????? ???????????? ????????????????? ??????????????

??? - Radar gun (or) speed gun

??????????????????? http://www.radargunsblog.com/ ???????????????????


Thursday, February 18, 2010

Unambiguous effect

??? (?) unambiguous effect

Unambiguous effect ???????? ?????????????????????????????????????? transmitted signal ??? pulse ??????????????????? reflected signal???pulse ?????? ???????????????????????? ???? reflected signal pulse ?????? ??? pulse??????????????? ????? ???????????? ???????????????? ????????????????????????????????? ?????????????????? ???(?) ??????????? ?????????????? ???????? signal ?? transmitted signal ???????????????????? ????????? received signal ??? signal ??? 1 , 2 , 3 ??????????????????? pulse ??????????????????????????? transmitted signal ??? first pulse(1)???????????? ??????????????? ????????? ????????? received signal ???(1) ??? ????????????????? ?????????????????????????????? ?????????????????????? ???????????? transmitted signal ?? ????? pulse ??????????????? ?????????????????????? ??????????????????????? (???????) ??? pulse ??????? ??? pulse ????????????????? ??????????????????????????? ?????????????????? 1 , 2, 3 ... ?????????????1 ? 1 ??????? ?????????????????????? ??????????? signal ??? ?????????????????????????????? ????????????????????? pulse ?????????? ???????????? ???????????????? pulse ????????????????????????? ??????????? ???? ????????????????????????????????? ????????????? ??????????????????? ???????????????? ????????????????? ?????????????? received signal pulse ?? ??? transmitted signal?????? pulse ????????????????????????? ????????????????????????? ????????????? ???????????????? ???????????????????? transmitted signal ??? period ( 免费观看特别黄大片 ) ????????????????? ??????????????? ???????????????? ??????????????????????? ????????? reflected ( received ) signal ?? t=2R/c ????????? ????????????????? ????????????????? ???????????????????????????? signal ?????????????????????????? ?????? ????????????? ???????????? ? t= 2Rmax/c ????? ??????????????????? transmitted signal ???period ????????????????????????????? T > t ? ????????????????????????? received signal ??? ??????? pulse ?? ????????????????? ????????????????? transmitted signal pulse ???????? ?????????????????????????????????? ????????????? received signal pulse ?? ??? ??????????????????? transmitted signal pulse ??????????????????????????? ?????????????? ??????????????? unambiguous effect ????????????????????? ?????????????? ????????????? signal ??? period ???????????????? ?? unambiguous effect ?????????? ?????????????????????????????

T >2Rmax/c

Wednesday, October 21, 2009

Frequency radio range finders with symmetrical linear frequency modulation

???(?) Frequency radio range finders with symmetrical linear frequency modulation

Frequency radio range finders with nonsymmetrical linear frequency modulation ????????????????Doppler effect ?????????????????? ?????? ????? ????????? target ?????? range ?????????????????????????? ???????? ?????????? target ?????? range ?????????? ????????????????????????????????????? ??? ????????????????? Doppler effect ??????????????????????? ?????????? reflected signal ????????????? beat frequency ?? ?????????????????????????????????????? ?????????? Doppler ???????????????? signal ??? symmetrical linear frequency modulation ????????????? beat frequency ????????????? ?????? ????????????????? ???????? Doppler ?????????? beat frequency ?? ??????????????? beat frequency (1) ????? beat frequency (2) ??????? ?????????????????? ??????? ?????? Doppler effect ??????? ?????????? ?????????? Doppler effect ????????? ??????????????? ??????????????????? beat frequency ??? Doppler frequency ??? ????????????????? beat frequency ?????????? Frequency radio range finders with nonsymmetrical linear frequency modulation ??????????? ????????????? ???????????? target ??? ?????????????????????? ?????????????????????????? ?? system ??????? ????????????? ???????????? target ?? ??????????????? ?????????????? ?????? ??????????? ???????? ????????????????????????????