Mene ne hanyoyi guda uku daban-daban na SAR?

1. Menene SARrarrabuwar kawuna?
Rarrabawa: Rarrabawa ta kwance ta H; Rarrabawa ta tsaye ta V, wato, alkiblar girgiza ta filin lantarki. Lokacin da tauraron dan adam ya aika sigina zuwa ƙasa, alkiblar girgiza ta raƙuman rediyo da ake amfani da su na iya kasancewa ta hanyoyi da yawa. Waɗanda ake amfani da su a halin yanzu sune:

Rarrabawa a kwance (H-kwance): Rarrabawa a kwance yana nufin cewa lokacin da tauraron dan adam ya aika sigina zuwa ƙasa, alkiblar girgizar raƙuman rediyonsa tana kwance. Rarrabawa a tsaye (V-kwance): Rarrabawa a tsaye yana nufin cewa lokacin da tauraron dan adam ya aika sigina zuwa ƙasa, alkiblar girgizar raƙuman rediyonsa tana tsaye.

An raba watsawar raƙuman lantarki zuwa raƙuman kwance (H) da raƙuman tsaye (V), kuma an raba karɓa zuwa H da V. Tsarin radar da ke amfani da rarrabuwar layi na H da V yana amfani da alamomi guda biyu don wakiltar rabuwar watsawa da karɓa, don haka yana iya samun tashoshi masu zuwa—HH, VV, HV, VH.

(1) HH - don watsawa a kwance da kuma karɓar a kwance

(2) VV - don watsawa a tsaye da kuma karɓar a tsaye

(3) HV - don watsawa a kwance da kuma karɓar a tsaye

(4) VH - don watsawa a tsaye da kuma karɓar kwance

Ana kiran waɗannan haɗin polarization guda biyu na farko da polarization iri ɗaya saboda polarizations na transmit da receive iri ɗaya ne. Haɗin biyu na ƙarshe ana kiransu polarizations na cross saboda polarizations na transmit da receive suna da daidaito a junansu.

2. Menene rarrabuwar kai ɗaya, rabuwar kai biyu, da cikakken rabuwa a cikin SAR?

Polarization guda ɗaya yana nufin (HH) ko (VV), wanda ke nufin (watsawa a kwance da karɓar kwance) ko (watsawa a tsaye da karɓar tsaye) (idan kuna nazarin fannin radar yanayi, gabaɗaya yana (HH).)

Rarrabawa ta biyu tana nufin ƙara wani yanayin rabuwa a cikin yanayin rabuwa ɗaya, kamar watsawa ta kwance (HH) da watsawa ta kwance + (HV) da karɓa ta tsaye.

Cikakken fasahar polarization ita ce mafi wahala, tana buƙatar watsa H da V a lokaci guda, wato, hanyoyin polarization guda huɗu na (HH) (HV) (VV) (VH) suna wanzuwa a lokaci guda.

Tsarin radar na iya samun matakai daban-daban na rikitarwar polarization:

(1) Rarrabawa guda ɗaya: HH; VV; HV; VH

(2)Rarrabawa biyu: HH+HV; VV+VH; HH+VV

(3) Rarrabuwa huɗu: HH+VV+HV+VH

Radars na Orthogonal polarization (watau cikakken polarization) suna amfani da waɗannan polarizations guda huɗu kuma suna auna bambancin mataki tsakanin tashoshi da kuma girman. Wasu radars na polarization guda biyu kuma suna auna bambancin mataki tsakanin tashoshi, saboda wannan matakin yana taka muhimmiyar rawa wajen fitar da bayanai na polarization.

Hoton tauraron dan adam na radar Dangane da rarrabuwar radar, abubuwa daban-daban da aka lura suna watsa raƙuman rarrabuwar radar daban-daban don raƙuman rarrabuwar radar da suka faru daban-daban. Saboda haka, na'urar gano nesa ta sararin samaniya na iya amfani da madaukai da yawa don ƙara abubuwan da ke cikin bayanai, ko amfani da rarrabuwar radar daban-daban don haɓakawa da inganta daidaiton gano manufa.

3. Yadda ake zaɓar yanayin polarization na tauraron dan adam na SAR radar?

Kwarewa ta nuna cewa:

Don aikace-aikacen ruwa, HH polarization na ƙungiyar L ya fi sauƙi, yayin da VV polarization na ƙungiyar C ya fi kyau;

Ga ciyawa da hanyoyi masu ƙarancin watsewa, rarrabuwar kwance yana sa abubuwan su sami bambance-bambance mafi girma, don haka SAR mai sararin samaniya da ake amfani da shi don taswirar ƙasa yana amfani da rarrabuwar kwance; ga ƙasa mai kauri fiye da tsayin tsayi, babu wani canji a bayyane a cikin HH ko VV.

Ƙarfin amsawar abu ɗaya a ƙarƙashin rarrabuwar ra'ayoyi daban-daban ya bambanta, kuma sautin hoton ma ya bambanta, wanda ke ƙara bayanin gano abin da aka nufa. Kwatanta bayanin rabuwar ra'ayoyi iri ɗaya (HH, VV) da rabuwar ra'ayoyi (HV, VH) na iya ƙara yawan bayanan hoton radar, kuma bambancin bayanai tsakanin amsawar rabuwar ra'ayoyi na shuke-shuke da sauran abubuwa daban-daban ya fi saurin fahimta fiye da bambancin da ke tsakanin ƙungiyoyi daban-daban.
Saboda haka, a aikace-aikace masu amfani, ana iya zaɓar yanayin polarization da ya dace bisa ga buƙatu daban-daban, kuma cikakken amfani da hanyoyin polarization da yawa yana da amfani don inganta daidaiton rarrabuwar abubuwa.