Peb hom polarization sib txawv ntawm SAR yog dab tsi?

1. SAR yog dab tsikev sib cais?
Kev sib hloov: H kab rov tav polarization; V ntsug polarization, uas yog, qhov kev taw qhia ntawm lub zog hluav taws xob. Thaum lub satellite xa lub teeb liab mus rau hauv av, qhov kev taw qhia ntawm lub xov tooj cua siv tau ntau txoj hauv kev. Cov uas siv tam sim no yog:

Kev sib hloov kab rov tav (H-kab rov tav): Kev sib hloov kab rov tav txhais tau tias thaum lub satellite xa lub teeb liab mus rau hauv av, qhov kev taw qhia ntawm nws lub xov tooj cua yog kab rov tav. Kev sib hloov kab ntsug (V-kab rov tav): Kev sib hloov kab rov tav txhais tau tias thaum lub satellite xa lub teeb liab mus rau hauv av, qhov kev taw qhia ntawm nws lub xov tooj cua yog kab rov tav.

Kev xa xov hluav taws xob electromagnetic yog muab faib ua cov nthwv dej kab rov tav (H) thiab nthwv dej ntsug (V), thiab kev txais tos kuj tau muab faib ua H thiab V. Lub radar system siv H thiab V linear polarization siv ob lub cim los sawv cev rau kev xa xov thiab kev txais tos polarization, yog li nws tuaj yeem muaj cov channel hauv qab no - HH, VV, HV, VH.

(1) HH - rau kev xa kab rov tav thiab kev txais kab rov tav

(2) VV - rau kev xa xov ntsug thiab kev txais tos ntsug

(3) HV - rau kev sib kis kab rov tav thiab kev txais tos ntsug

(4) VH - rau kev xa xov ntsug thiab kev txais kab rov tav

Ob qho kev sib xyaw ua ke ntawm polarization no thawj zaug hu ua polarizations zoo sib xws vim tias qhov kev sib xyaw ua ke ntawm kev xa thiab kev txais yog tib yam. Ob qho kev sib xyaw ua ke kawg hu ua kev sib xyaw ua ke hla vim tias qhov kev sib xyaw ua ke ntawm kev xa thiab kev txais yog orthogonal rau ib leeg.

2. Dab tsi yog ib qho polarization, ob qho polarization, thiab tag nrho polarization hauv SAR?

Ib qho polarization txhais tau tias (HH) lossis (VV), uas txhais tau tias (kab rov tav thiab kab rov tav txais tos) lossis (kab rov tav thiab kab rov tav txais tos) (yog tias koj tab tom kawm txog thaj chaw ntawm radar huab cua, nws feem ntau yog (HH).)

Dual polarization hais txog kev ntxiv lwm hom polarization rau ib hom polarization, xws li (HH) kab rov tav kis thiab kab rov tav txais + (HV) kab rov tav kis thiab ntsug txais.

Kev siv tshuab polarization tag nrho yog qhov nyuaj tshaj plaws, xav tau kev sib kis ntawm H thiab V tib lub sijhawm, uas yog, plaub hom polarization ntawm (HH) (HV) (VV) (VH) muaj nyob rau tib lub sijhawm.

Cov kab ke radar tuaj yeem muaj ntau qib sib txawv ntawm qhov nyuaj ntawm polarization:

(1) Ib qho polarization: HH; VV; HV; VH

(2)Ob lub polarization: HH+HV; VV+VH; HH+VV

(3) Plaub qhov polarizations: HH+VV+HV+VH

Cov radar orthogonal polarization (piv txwv li polarization tag nrho) siv plaub qhov polarizations no thiab ntsuas qhov sib txawv ntawm cov channel nrog rau qhov amplitude. Qee cov radar dual-polarization kuj ntsuas qhov sib txawv ntawm cov channel, vim tias qhov theem no ua lub luag haujlwm tseem ceeb hauv kev rho tawm cov ntaub ntawv polarization.

Cov duab radar satellite Hauv cov nqe lus ntawm polarization, cov khoom sib txawv uas tau pom rov qab sib txawv polarization nthwv dej rau ntau yam polarization nthwv dej. Yog li ntawd, qhov chaw deb sensing tuaj yeem siv ntau txoj kab sib txawv los nce cov ntsiab lus ntawm cov ntaub ntawv, lossis siv ntau yam polarizations los txhim kho thiab txhim kho qhov tseeb ntawm kev txheeb xyuas lub hom phiaj.

3. Yuav ua li cas xaiv hom polarization ntawm SAR radar satellite?

Kev paub dhau los qhia tau tias:

Rau cov ntawv thov hauv dej hiav txwv, HH polarization ntawm L band yog qhov rhiab heev dua, thaum VV polarization ntawm C band zoo dua;

Rau cov nyom thiab txoj kev uas tsis muaj kev sib kis, kev sib hloov kab rov tav ua rau cov khoom muaj qhov sib txawv ntau dua, yog li SAR uas siv rau kev kos duab av siv kev sib hloov kab rov tav; rau thaj av uas muaj qhov ntxhib ntau dua li qhov ntev ntawm lub teeb, tsis muaj kev hloov pauv pom tseeb hauv HH lossis VV.

Lub zog echo ntawm tib yam khoom nyob rau hauv ntau yam polarizations yog txawv, thiab lub suab duab kuj txawv, uas ua rau cov ntaub ntawv rau kev txheeb xyuas lub hom phiaj ntawm yam khoom. Kev sib piv cov ntaub ntawv ntawm tib lub polarization (HH, VV) thiab cross-polarization (HV, VH) tuaj yeem ua rau cov ntaub ntawv duab radar nce ntxiv, thiab qhov sib txawv ntawm cov ntaub ntawv ntawm polarization echoes ntawm cov nroj tsuag thiab lwm yam khoom sib txawv yog rhiab heev dua li qhov sib txawv ntawm ntau yam bands.
Yog li ntawd, hauv kev siv ua haujlwm, hom polarization tsim nyog tuaj yeem xaiv tau raws li qhov xav tau sib txawv, thiab kev siv ntau hom polarization yog qhov zoo rau kev txhim kho qhov tseeb ntawm kev faib khoom.