Kedu ụdị polarization atọ dị iche iche nke SAR?

1. Gịnị bụ SARpolarisation?
Mgbawa: Mgbawa kwụ ọtọ H; Mgbawa kwụ ọtọ V, ya bụ, ntụzịaka mkpọtụ nke ubi elektrọnik. Mgbe satịlaịtị na-ebuga mgbaama n'ala, ntụzịaka mkpọtụ nke ebili redio ejiri nwere ike ịdị n'ọtụtụ ụzọ. Ndị eji ugbu a bụ:

Mgbawa kwụ ọtọ (H-horizontal): Mgbawa kwụ ọtọ pụtara na mgbe satịlaịtị na-ebuga mgbama gaa n'ala, ntụwa jijiji nke ebili redio ya na-adị kwụ ọtọ. Mgbawa kwụ ọtọ (V-vetikal): Mgbawa kwụ ọtọ pụtara na mgbe satịlaịtị na-ebuga mgbama gaa n'ala, ntụwa jijiji nke ebili redio ya na-adị kwụ ọtọ.

A na-ekewa nnyefe ebili mmiri elektrọnik n'ime ebili mmiri kwụ ọtọ (H) na ebili mmiri kwụ ọtọ (V), a na-ekewakwa nnata n'ime H na V. Sistemụ radar nke na-eji polarization ahịrị H na V na-eji akara abụọ anọchite anya polarization nnyefe na nnata, yabụ ọ nwere ike inwe ọwa ndị a—HH, VV, HV, VH.

(1) HH - maka nnyefe kwụ ọtọ na nnabata kwụ ọtọ

(2) VV - maka nnyefe kwụ ọtọ na nnabata kwụ ọtọ

(3) HV - maka nnyefe kwụ ọtọ na nnabata kwụ ọtọ

(4) VH - maka nnyefe kwụ ọtọ na nnabata kwụ ọtọ

A na-akpọ njikọta polarization abụọ mbụ a polarization yiri nke ahụ n'ihi na polarization transmit na receive bụ otu. A na-akpọ njikọta abụọ ikpeazụ polarizations cross n'ihi na polarization transmit na receive bụ orthogonal n'etiti onwe ha.

2. Kedu ihe bụ otu polarization, dual polarization, na full polarization na SAR?

Otu polarization na-ezo aka na (HH) ma ọ bụ (VV), nke pụtara (nnyefe kwụ ọtọ na nnabata kwụ ọtọ) ma ọ bụ (nnyefe kwụ ọtọ na nnakwere kwụ ọtọ) (ọ bụrụ na ị na-amụ ubi nke radar ihu igwe, ọ na-abụkarị (HH).)

Mgbawa abụọ pụtara ịgbakwunye ụdị mgbawa ọzọ na otu ụdị mgbawa, dịka nnyefe kwụ ọtọ (HH) na nnyefe kwụ ọtọ + (HV) na nnyefe kwụ ọtọ.

Teknụzụ polarization zuru oke bụ nke kacha sie ike, nke chọrọ nnyefe nke H na V n'otu oge, ya bụ, ụdị polarization anọ nke (HH) (HV) (VV) (VH) dị n'otu oge.

Sistemụ radar nwere ike ịnwe ọkwa dị iche iche nke mgbagwoju anya polarization:

(1) Otu polarization: HH; VV; HV; VH

(2)Mgbakwunye abụọ: HH+HV; VV+VH; HH+VV

(3) Mkpụkọ anọ: HH+VV+HV+VH

Rada nke orthogonal polarization (ya bụ, polarization zuru oke) na-eji polarization anọ ndị a ma tụọ ọdịiche nke usoro dị n'etiti ọwa yana oke. Ụfọdụ radar nke polarization abụọ na-atụkwa ọdịiche nke usoro dị n'etiti ọwa, ebe ọ bụ na usoro a na-arụ ọrụ dị mkpa na mwepụta ozi polarization.

Foto satịlaịtị radar Banyere polarization, ihe dị iche iche a hụrụ na-agbasa ebili mmiri polarization dị iche iche maka ebili mmiri polarization dị iche iche merenụ. Ya mere, nchọpụta oghere nwere ike iji ọtụtụ eriri iji mee ka ọdịnaya ozi dịkwuo elu, ma ọ bụ jiri polarization dị iche iche mee ka ma melite izi ezi nke njirimara ebumnuche.

3. Kedu otu esi ahọrọ ụdị polarization nke satịlaịtị radar SAR?

Ahụmịhe na-egosi na:

Maka ojiji mmiri, HH polarization nke L band na-enwe mmetụta karịa, ebe VV polarization nke C band ka mma;

Maka ahịhịa na okporo ụzọ ndị na-agbasasị ala, polarization kwụ ọtọ na-eme ka ihe ndị ahụ nwee nnukwu ọdịiche, yabụ SAR nke nwere oghere ejiri mee ihe maka maapụ ala na-eji polarization kwụ ọtọ; maka ala nwere oke ike karịa ogologo ebili mmiri, enweghị mgbanwe doro anya na HH ma ọ bụ VV.

Ike ụda olu nke otu ihe ahụ n'okpuru polarizations dị iche iche dị iche, ụda onyonyo ahụ dịkwa iche, nke na-eme ka ozi dịkwuo elu maka ịchọpụta ihe a na-achọ. Ịtụnyere ozi nke otu polarization (HH, VV) na cross-polarization (HV, VH) nwere ike ime ka ozi radar dịkwuo elu nke ukwuu, ọdịiche ozi dị n'etiti ụda olu polarization nke osisi na ihe ndị ọzọ dị iche iche na-enwe mmetụta karịa ọdịiche dị n'etiti eriri dị iche iche.
Ya mere, n'ọrụ bara uru, enwere ike ịhọrọ ụdị polarization kwesịrị ekwesị dịka mkpa dị iche iche si dị, ojiji zuru oke nke ọtụtụ ụdị polarization na-enyekwa aka ime ka izi ezi nke nhazi ihe dịkwuo mma.