Polarization ya SARisobanura icyerekezo cy'umurima wa elegitoroniki woherezwa kandi wakirwa na sisitemu ya radar y'ubukorikori. Kubera ko ubuso n'imiterere bitandukanye bitatanya imirima itambitse n'ihagaze mu buryo butandukanye, polarization ni imwe mu mpinduka z'ingirakamaro cyane mu gusobanura amashusho ya SAR.
Iyi nyandiko isobanura inzira enye za polarization - HH, HV, VH na VV - hamwe n'uburyo butatu bukoreshwa cyane bwo kubona: polarization imwe, polarization ebyiri na polarization yuzuye (quad). Igaragaza kandi uburyo injeniyeri zihitamo uburyo bwo kureba kure, gupima radar no gusuzuma sisitemu ya antenne.
Polarization ya SAR ni iki?
Sisitemu nyinshi za SAR zo mu kirere zikoresha polarization igororotse (H) na vertical (V). Kode y'umuyoboro w'inyuguti ebyiri igaragaza polarization yoherejwe mbere na mbere, naho polarization yakiriwe ikaza kabiri. Urugero, HH bivuze kohereza no kwakira mu buryo butambitse, mu gihe HV bivuze kohereza no kwakira mu buryo butambitse.
Polarization ni ingenzi kuko intego ishobora kubungabunga polarization y’ibyabaye, kuyizunguruka cyangwa gukuraho polari igice cy’igaruka. Ubukana bw’ubuso, imiterere ya dielectric, uburebure bw’umurambararo, inguni y’ibiza n’imiterere y’imbere byose bigira ingaruka ku gukwirakwiza inyuma. Polarization rero igomba gusobanurwa hamwe n’umurongo w’impinduka, imiterere y’ishusho n’amakuru y’ishusho yagenzuwe.
HH, HV, VH na VV Bisobanura iki?
| Umuyoboro | Kohereza | Wakira | Gushyira mu byiciro |
|---|---|---|---|
| HH | Igororotse | Igororotse | Ihuriweho n'abantu benshi |
| HV | Igororotse | Ihagaze | Ifite polari inyuranyije |
| VH | Ihagaze | Igororotse | Ifite polari inyuranyije |
| VV | Ihagaze | Ihagaze | Ihuriweho n'abantu benshi |
HH na VV ni imiyoboro ya polarized hamwe kuko polarized zohereza n'izakira ari zimwe. HV na VH ni imiyoboro ya polarized hagati y'impande kuko polarized yo kwakira iba ingana na polarized yoherejwe. Muri sisitemu ya monostatic ya calibrated, ibisubizo bya HV na VH akenshi biba bisa, ariko imiyoboro yombi igumana mu bipimo byuzuye bya polarimetric.
Uburyo Butatu Bukuru bwa SAR Polarization
1. Polarization imwe
Gushakisha amakuru hakoreshejwe polarisation imwe gusa bigenzura umuyoboro umwe, cyane cyane HH cyangwa VV. Bitanga ingano nto y'amakuru no koroshya gutunganya amakuru iyo umuyoboro umwe wemewe uhagije. Imbogamizi ni uko umuyoboro umwe utanga amakuru make ku bijyanye n'uburyo bwo gukwirakwiza amakuru n'imiterere y'intego.
2. Guhuza ibice bibiri (Dual Polarization)
Uburyo bwo kubona imiterere y’ingufu ebyiri (dual-polarisation) bufata inzira ebyiri. Ihuriro rusange ririmo HH+HV na VV+VH, aho radar yohereza imiterere imwe y’ingufu (polarisation) kandi ikabona inyungu za co- na cross-polarized. Hari na sisitemu zishyigikira co-pol ebyiri nka HH+VV. Amakuru ya dual-pol yongeraho ivangura ry’ingirakamaro mu gihe atuma ibisabwa mu gupima amakuru no kuyatunganya birushaho gucungwa neza kurusha polarimetry yuzuye. ESA ivuga ko Sentinel-1 ishyigikira VV+VH cyangwa HH+HV muri gahunda zayo za dual-polarisation.
3. Polarization yuzuye cyangwa ine
SAR yuzuye ya polarimetric yandika HH, HV, VH na V nk'imiyoboro igoye. Radar ya kera ya quad-pol yohereza H na V mu buryo bukurikiranye kandi ikakira H na V, ibika amakuru y'ubwinshi n'uburyo bwo guhuza. Ibi bishyigikira isesengura rya scattering-matrix no gusesengura intego, gushyira mu byiciro no kuyigaragaza.
Impinduka ni uko sisitemu ikomeye, gukenera gupima, ingano y'amakuru n'imbaraga zo kuyatunganya. Bitewe n'uburyo sensor ikoresha, imikorere ya pol yose ishobora no gusaba inzira nto cyangwa izindi mbogamizi zo kubona. Polarization nto ni ubundi buryo bwa SAR bwemewe, ariko butandukanye n'uburyo gakondo bwa single-, dual- na quad-pol linear bwavuzwe hano.
Ubwiyongere bw'Ubukungu (Co-Polarization) vs. Ubwiyongere bw'Ubukungu (Cross-Polarization)
Imiyoboro ya Co-polarized ikunze kubika impinduka zikomeye zituruka ku buso n'imiterere bikomeza polarized yandujwe. Igaruka rya Cross-polarized rigaragaza ko inzira yo gukwirakwira yahinduye igice cy'imiterere ya polarized binyuze mu gukwirakwira kw'ingano, ubwinshi bw'ibishushanyo, imiterere igoye cyangwa imiterere ya anisotropic.
- Amazi atuje n'ubuso buroroshye:akenshi bigaragara nk'umwijima iyo ingufu nyinshi zigaragara kure y'aho zigaragara; ubukana bw'umuyaga, inguni y'umuyaga n'inguni y'ihindagurika ry'ikirere bishobora kongera ihindagurika ry'ikirere.
- Ibimera:amashami, amashami n'amababi bituma habaho gukwirakwira kw'ibice, bityo imiyoboro inyuranamo ishobora kongeramo amakuru y'ingirakamaro mu miterere.
- Uduce tw'imijyi:Inyubako n'ubuso bw'ubutaka bishobora gutanga umusaruro ukomeye wa co-pol no gukwirakwira kw'ibice bibiri, bitewe n'icyerekezo n'imiterere y'ishusho.
- Ubutaka, urubura n'urubura:Ubushuhe, ubukana, uburebure bw'umurambararo, uburebure bw'umuraba n'imiterere y'imbere byose bigira ingaruka ku buryo polarisation yitabazwa.
Aya ni amahame yo gusobanura aho kuba amategeko rusange. Umuyoboro ntugomba gutoranywa hifashishijwe umurongo wa radar, inguni y’ihindagurika ry’ikirere, ubushobozi bwo gusuzuma, igihe cy’izuba n’ubwiza bwawo.
Uburyo bwo Guhitamo Uburyo bwo Guhuza SAR
| Ibisabwa | Aho gutangirira hafatika |
|---|---|
| Gukurikirana mu karere kagutse cyangwa ingano nto y'amakuru | Isuzuma rimwe gusa iyo umuyoboro wemewe uhuye n'intego yo kuwumenya |
| Itandukaniro hagati y'ibimera, ubuhinzi cyangwa ubutaka | Amakuru ya "Dual-pol co-" na "cross-polarized" kugira ngo hongerwe amakuru akwirakwira |
| Ikarita y'urubura rwo mu nyanja, inyanja cyangwa imyuzure | Hitamo uburyo bushingiye kuri HH- cyangwa VV ukurikije umugozi, inguni y'icyorezo n'uburyo bwemejwe |
| Gushyira mu byiciro bihanitse cyangwa gusenyuka gukwirakwira | Impande enye (quad-pol) yuzuye iyo hakenewe amakuru y’imiyoboro ine agenzurwa na phase-calibrated |
Uburyo bwiza ni ubwo gukoresha porogaramu. Abahanga mu by'ikoranabuhanga bagomba kugereranya ibikubiye mu makuru n'uburyo akoreshwa, ubushobozi bwo gukemura ibibazo, uburyo ibimenyetso bikoreshwa mu gupima urusaku, uburyo bwo gusubiramo amakuru, uburyo bwo kuyasuzuma, uburyo bwo kuyatunganya ndetse n'ubushobozi bwo kuyasuzuma.
Ibitekerezo kuri Antena na RF kuri Radar ya Polarimetric
Ibipimo byizewe bya polarimetirike bishingiye ku birenze algorithme yo gutunganya. Antene na RF chain bigomba kugumana imikorere ihamye muri polarisation channels zombi. Ibipimo by'ingenzi birimo:
- inshuro z'imikorere n'umuvuduko w'amakuru ako kanya;
- uburinganire bw'ubwiyongere n'imiterere y'imirasire hagati y'ibyambu bya H na V;
- kwitandukanya kw'ibyambu n'ivangura hagati y'ibihugu byombi;
- amplitude n'ihindagurika ry'ibyiciro;
- VSWR, aho guhuza no gupima insinga;
- guhuza antene, gushyiraho imiterere y'aho ibintu bihurira n'aho bigarukira.
Ibikoresho bya RF MISOantene z'amahoni afite polarize ebyiri, antene za interineti zifite polarize ebyirin'izindi RF antene zikoreshwa mu gupima no guhuza sisitemu. Guhitamo moderi bigomba gushingira ku rupapuro rw'amakuru ruriho ubu n'ibisabwa byuzuye mu isuzuma.
Ibibazo Bikunze Kubazwa
Ni iyihe nyuguti iza imbere muri kode ya SAR polarization?
Inyuguti ya mbere igaragaza polarisation yoherejwe naho iya kabiri ikagaragaza polarisation yakiriwe. HV bivuga kohereza mu buryo butambitse n'aho kwakira mu buryo buhagaze.
Ni irihe tandukaniro riri hagati ya dual-pol na quad-pol SAR?
Dual-pol yandika imiyoboro ibiri, akenshi HH+HV cyangwa VV+VH. Quad-pol yandika HH, HV, VH na VV kandi ikabungabunga isano ikenewe kugira ngo habeho isesengura ryuzuye rya polarimetric.
Ese polarisation imwe ya SAR niyo nziza buri gihe?
Oya. Uburyo bw'ingirakamaro cyane bushingira ku ntego, uburebure bw'umurambararo wa radar, inguni y'ingaruka, igisubizo, imiterere y'ibidukikije n'intego yo kubitunganya.
Kuki inzira za politiki zitandukanye ari ingirakamaro?
HV cyangwa VH bishobora kugaragaza gukwirakwira kw'ibimera bihindura ubwiyongere bw'ibimera, cyane cyane gukwirakwira kw'ibimera n'intego zikomeye nk'ibimera.
Umwanzuro
Polarization ya SAR igenzura uburyo radar imurikira intego n'uburyo umurima usubijwe upimwa. HH na VV ni imiyoboro ya co-polarized, mu gihe HV na VH bikorerwa polarized. Single-pol itanga umusaruro, dual-pol yongeraho itandukaniro, naho full quad-pol itanga amakuru yuzuye ya linear polarimetric. Ibisubizo nyabyo bisaba ko uburyo bwo kubona, sisitemu ya antene, uburyo bwo gupima n'ibisabwa mu ikoreshwa bisuzumwa hamwe.
Kugira ngo umenye guhitamo antene cyangwa ubufasha bwo gupima RF ya polarimetric, reba RF MISO'subushobozi bwo gupima antene or hamagara itsinda rya RF MISO.
Inyandiko zishingiye ku byo wasomye n'ibindi byaguzwe
Kugira ngo umenye byinshi kuri antene, sura:
Igihe cyo kohereza: Kamena-28-2024
