Waa maxay saddexda nooc ee kala duwan ee polarization ee SAR?

1. Waa maxay SARpolarization?
Polarization: H polarization horizontal; V polarization vertical, taas oo ah, jihada gariirka ee goobta korantada. Marka uu dayax gacmeedku u gudbiyo calaamada dhulka, jihada gariirka ee mowjadda raadiyaha ee la isticmaalo waxay noqon kartaa siyaabo badan. Kuwa hadda la isticmaalo waa:

Horizontal polarization (H-horizontal): Horizontal polarization macnaheedu waa in marka uu dayax gacmeedku u gudbiyo signalka dhulka, jihada gariirka ee hirarkiisu waa jiif. Vertical polarization (V-vertical): Polarization vertical macnaheedu waa marka uu dayax-gacmeedku u gudbiyo signalka dhulka, jihada gariirka ee hirarka raadiyaha ayaa toosan.

Gudbinta hirarka Electromagnetic waxa loo kala qaybiyaa mowjado siman (H) iyo mowjado toosan (V), soo dhawayntuna waxa ay sidoo kale u qaybsantaa H iyo V. Nidaamka radar-ka ee isticmaalaya H iyo V linear polarization waxa uu isticmaalaa calaamado laba calaamadood ah si ay u matalaan gudbinta iyo soo dhawaynta polarization. si ay u yeelan karto kanaalada soo socda-HH, VV, HV, VH.

(1) HH - ee gudbinta toosan iyo soo dhawayn toos ah

(2) VV - gudbinta tooska ah iyo soo dhaweynta tooska ah

(3) HV - gudbinta tooska ah iyo soo dhaweynta toosan

(4) VH - gudbinta tooska ah iyo soo dhaweynta tooska ah

Labadan ugu horreeya ee isku-dhafka polarization-ka waxaa loo yaqaan polarizations isku mid ah sababtoo ah gudbinta iyo helitaanka polarizations waa isku mid. Labada isku darka ee ugu dambeeya waxaa loo yaqaan 'cross polarizations' sababtoo ah gudbinta iyo helitaanka polarizations waa midba midka kale.

2. Maxay yihiin hal polarization, dual polarization, iyo polarization full in SAR?

Hal polarization waxaa loola jeedaa (HH) ama (VV), taas oo macnaheedu yahay (gudbinta toosan iyo soo dhaweynta tooska ah) ama ( gudbinta tooska ah iyo soo dhawaynta tooska ah ) (haddii aad baranayso goobta radar saadaasha hawada, guud ahaan waa (HH))

Dual polarization waxaa loola jeedaa in lagu daro qaab kale oo kala soocida hal qaab, sida (HH) gudbinta tooska ah iyo qaabilaadda jiifka ah + (HV) gudbinta tooska ah iyo soo dhaweynta toosan.

Tiknoolajiyada buuxa ee polarization waa tan ugu adag, oo u baahan gudbinta isku mar ee H iyo V, taas oo ah, afarta nooc ee polarization ee (HH) (HV) (VV) (VH) ayaa jira isku mar.

Nidaamyada radar waxay yeelan karaan heerar kala duwan oo kakanaanta polarization:

(1) Hal-ku-dhigid: HH; VV; HV; VH

(2)Dual polarization: HH+HV; VV+VH; HH+VV

(3) Afar kala sooc: HH+VV+HV+VH

Polarization Orthogonal (ie polarization full) radar waxay adeegsadaan afartan polarizations waxayna cabbiraan faraqa u dhexeeya kanaalada iyo sidoo kale baaxadda. Qaar ka mid ah raadarada laba-geesoodka ah ayaa sidoo kale cabbira farqiga wajiga u dhexeeya kanaalada, maadaama wajigani uu door muhiim ah ka ciyaaro soo saarista macluumaadka polarization.

Sawirka dayax-gacmeedka Radar Marka la eego polarization, walxaha kala duwan ee la arkay waxay dib u firdhiyaan hirarka polarization ee kala duwan ee hirarka kala duwan ee shilka. Sidaa darteed, dareemada fogaanta meel bannaan waxay isticmaali kartaa kooxo badan si ay u kordhiso macluumaadka ku jira, ama u isticmaasho polarizations kala duwan si kor loogu qaado loona hagaajiyo saxnaanta aqoonsiga bartilmaameedka.

3. Sidee loo doortaa habka polarization ee dayax gacmeedka radar SAR?

Waayo-aragnimadu waxay muujinaysaa in:

Codsiyada badda, polarization HH ee band L ayaa aad u xasaasi ah, halka VV polarization ee band C ka fiican yahay;

Cawska iyo waddooyinka firidhsan ee hooseeya, polarization-ka toosan wuxuu ka dhigayaa shayada kala duwanaansho weyn, sidaa darteed SAR-ka hawada sare ee loo isticmaalo khariidaynta dhulku waxay isticmaashaa polarization horizontal; Dhulka leh qallafsanaanta ka weyn hirarka dhererka, ma jiro isbeddel muuqda oo HH ama VV ah.

Awoodda echo ee shay isku mid ah oo hoos yimaada kala duwanaansho kala duwan ayaa ka duwan, iyo codka sawirka ayaa sidoo kale ka duwan, taas oo kordhisa macluumaadka lagu aqoonsanayo bartilmaameedka shayga. Isbarbardhigga macluumaadka isku-xirnaanta isku midka ah (HH, VV) iyo is-dhaafsiga (HV, VH) waxay si weyn u kordhin karaan macluumaadka sawirka radar, farqiga macluumaadka ee u dhexeeya dhawaaqa polarization ee dhirta iyo walxaha kale ee kala duwan ayaa ka xasaasisan farqiga u dhexeeya kooxo kala duwan.
Sidaa darteed, codsiyada wax ku oolka ah, qaabka polarization ee ku habboon ayaa loo dooran karaa iyadoo loo eegayo baahiyo kala duwan, iyo isticmaalka guud ee hababka kala duwan ee kala-soocidda waxay ku habboon tahay hagaajinta saxnaanta kala-soocidda shayga.