{"id":3452,"date":"2023-12-26T19:15:36","date_gmt":"2023-12-26T12:15:36","guid":{"rendered":"https:\/\/opengis.vn\/?p=3452"},"modified":"2024-05-22T10:43:24","modified_gmt":"2024-05-22T03:43:24","slug":"xu-ly-du-lieu-vien-tham","status":"publish","type":"post","link":"https:\/\/opengis.vn\/en\/blog\/xu-ly-du-lieu-vien-tham\/","title":{"rendered":"X\u1eed l\u00fd d\u1eef li\u1ec7u vi\u1ec5n th\u00e1m"},"content":{"rendered":"

Ph\u00e2n t\u00edch d\u1eef li\u1ec7u t\u1eeb vi\u1ec5n th\u00e1m li\u00ean quan \u0111\u1ebfn vi\u1ec7c th\u1ef1c hi\u1ec7n m\u1ed9t s\u1ed1 b\u01b0\u1edbc nh\u1eb1m tr\u00edch xu\u1ea5t th\u00f4ng tin c\u00f3 \u00fd ngh\u0129a t\u1eeb h\u00ecnh \u1ea3nh ho\u1eb7c \u0111o l\u01b0\u1eddng c\u1ea3m bi\u1ebfn. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t t\u1ed5ng quan chung v\u1ec1 quy tr\u00ecnh:<\/p>\n\n\n\n

X\u00e1c \u0111\u1ecbnh Khu v\u1ef1c Nghi\u00ean c\u1ee9u<\/strong><\/em>: X\u00e1c \u0111\u1ecbnh ph\u1ea1m vi \u0111\u1ecba l\u00fd v\u00e0 ranh gi\u1edbi c\u1ee7a khu v\u1ef1c b\u1ea1n mu\u1ed1n ph\u00e2n t\u00edch s\u1eed d\u1ee5ng d\u1eef li\u1ec7u vi\u1ec5n th\u00e1m. \u0110i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 l\u00e0 m\u1ed9t khu v\u1ef1c c\u1ee5 th\u1ec3, m\u1ed9t th\u00e0nh ph\u1ed1, m\u1ed9t khu r\u1eebng ho\u1eb7c b\u1ea5t k\u1ef3 khu v\u1ef1c quan t\u00e2m n\u00e0o kh\u00e1c.<\/p>\n\n\n\n

Ch\u1ecdn D\u1eef li\u1ec7u Vi\u1ec5n th\u00e1m<\/em><\/strong>: L\u1ef1a ch\u1ecdn ngu\u1ed3n d\u1eef li\u1ec7u th\u00edch h\u1ee3p d\u1ef1a tr\u00ean m\u1ee5c ti\u00eau ph\u00e2n t\u00edch v\u00e0 \u0111\u1eb7c \u0111i\u1ec3m c\u1ee7a khu v\u1ef1c nghi\u00ean c\u1ee9u. C\u00e1c l\u1ef1a ch\u1ecdn bao g\u1ed3m h\u00ecnh \u1ea3nh v\u1ec7 tinh, \u1ea3nh h\u00e0ng kh\u00f4ng, d\u1eef li\u1ec7u LiDAR, d\u1eef li\u1ec7u radar, v.v. C\u00e2n nh\u1eafc c\u00e1c y\u1ebfu t\u1ed1 nh\u01b0 \u0111\u1ed9 ph\u00e2n gi\u1ea3i kh\u00f4ng gian, b\u0103ng ph\u1ed5, v\u00e0 ph\u1ea1m vi th\u1eddi gian.
C\u00e1c b\u1ea1n c\u00f3 th\u1ec3 tham kh\u1ea3o m\u1ed9t s\u1ed1 b\u00e0i vi\u1ebft c\u1ee7a OpenGIS v\u1ec1 c\u00e1c d\u1eef li\u1ec7u vi\u1ec5n th\u00e1m:
SPOT \u2013 Th\u1ebf h\u1ec7 v\u1ec7 tinh quan s\u00e1t Tr\u00e1i \u0111\u1ea5t \u2013 OpenGIS Vi\u1ec7t Nam<\/a>
MODIS \u2013 Gi\u1edbi thi\u1ec7u \u1ea3nh MODIS v\u00e0 c\u00e1c \u1ee9ng d\u1ee5ng \u2013 OpenGIS Vi\u1ec7t Nam<\/a>
\u1ea2nh vi\u1ec5n th\u00e1m ASTER v\u00e0 h\u01b0\u1edbng d\u1eabn t\u1ea3i \u1ea3nh ASTER GDEM \u2013 OpenGIS Vi\u1ec7t Nam<\/a><\/p>\n\n\n\n

Ti\u1ec1n x\u1eed l\u00fd<\/em><\/strong>: Tr\u01b0\u1edbc khi ph\u00e2n t\u00edch, \u1ea3nh vi\u1ec5n th\u00e1m th\u01b0\u1eddng c\u1ea7n ti\u1ec1n x\u1eed l\u00fd \u0111\u1ec3 hi\u1ec7u ch\u1ec9nh c\u00e1c v\u1ea5n \u0111\u1ec1 kh\u00e1c nhau. C\u00e1c b\u01b0\u1edbc ti\u1ec1n x\u1eed l\u00fd th\u00f4ng th\u01b0\u1eddng bao g\u1ed3m hi\u1ec7u ch\u1ec9nh kh\u00ed quy\u1ec3n, hi\u1ec7u ch\u1ec9nh b\u1ee9c x\u1ea1, hi\u1ec7u ch\u1ec9nh h\u00ecnh h\u1ecdc v\u00e0 hi\u1ec7u ch\u1ec9nh theo c\u1ea3m bi\u1ebfn c\u1ee5 th\u1ec3.<\/p>\n\n\n

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V\u00ed d\u1ee5 v\u1ec1 \u1ea3nh Landsat TM tr\u01b0\u1edbc (tr\u00e1i) v\u00e0 sau (ph\u1ea3i) khi hi\u1ec7u ch\u1ec9nh h\u00ecnh h\u1ecdc [1]<\/figcaption><\/figure><\/div>\n\n\n

T\u0103ng c\u01b0\u1eddng H\u00ecnh \u1ea3nh<\/em><\/strong>: T\u0103ng c\u01b0\u1eddng ch\u1ea5t l\u01b0\u1ee3ng h\u00ecnh \u1ea3nh \u0111\u1ec3 c\u1ea3i thi\u1ec7n vi\u1ec7c di\u1ec5n gi\u1ea3i. C\u00e1c k\u1ef9 thu\u1eadt nh\u01b0 k\u00e9o d\u00e3n \u0111\u1ed9 t\u01b0\u01a1ng ph\u1ea3n, c\u00e2n b\u1eb1ng histogram v\u00e0 pan-sharpening c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 t\u0103ng c\u01b0\u1eddng c\u00e1c \u0111\u1eb7c \u0111i\u1ec3m h\u00ecnh \u1ea3nh.<\/p>\n\n\n\n

Gi\u1ea3i \u0111o\u00e1n H\u00ecnh \u1ea3nh<\/em><\/strong>: M\u1ed9t trong nh\u1eefng nhi\u1ec7m v\u1ee5 ch\u00ednh trong ph\u00e2n t\u00edch vi\u1ec5n th\u00e1m l\u00e0 gi\u00e0i \u0111o\u00e1n h\u00ecnh \u1ea3nh, bao g\u1ed3m vi\u1ec7c g\u00e1n c\u00e1c pixel ho\u1eb7c \u0111\u1ed1i t\u01b0\u1ee3ng h\u00ecnh \u1ea3nh v\u00e0o c\u00e1c l\u1edbp ho\u1eb7c danh m\u1ee5c \u0111\u00e3 \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh tr\u01b0\u1edbc. \u0110i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n th\u00f4ng qua gi\u1ea3i \u0111o\u00e1n th\u1ee7 c\u00f4ng ho\u1eb7c thu\u1eadt to\u00e1n ph\u00e2n lo\u1ea1i t\u1ef1 \u0111\u1ed9ng nh\u01b0 ph\u01b0\u01a1ng ph\u00e1p ph\u00e2n lo\u1ea1i gi\u00e1m s\u00e1t ho\u1eb7c kh\u00f4ng gi\u00e1m s\u00e1t.<\/p>\n\n\n\n

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Gi\u1ea3i \u0111o\u00e1n th\u1ef1c ph\u1ee7 \u1ea3nh Landsat \u1edf khu v\u1ef1c Karlsruhe (\u0110\u1ee9c) [2]<\/figcaption><\/figure>\n\n\n\n

Tr\u00edch xu\u1ea5t \u0110\u1eb7c tr\u01b0ng<\/em><\/strong>: Tr\u00edch xu\u1ea5t c\u00e1c \u0111\u1eb7c tr\u01b0ng c\u1ee5 th\u1ec3 t\u1eeb d\u1eef li\u1ec7u vi\u1ec5n th\u00e1m c\u00f3 th\u1ec3 cung c\u1ea5p th\u00f4ng tin qu\u00fd gi\u00e1 cho vi\u1ec7c ph\u00e2n t\u00edch ti\u1ebfp theo. \u0110i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 bao g\u1ed3m x\u00e1c \u0111\u1ecbnh v\u00e0 ph\u00e2n chia \u0111\u1ed1i t\u01b0\u1ee3ng, \u0111o ch\u1ec9 s\u1ed1 th\u1ea3m th\u1ef1c v\u1eadt, t\u00ednh to\u00e1n nhi\u1ec7t \u0111\u1ed9 b\u1ec1 m\u1eb7t \u0111\u1ea5t ho\u1eb7c c\u00e1c th\u00f4ng s\u1ed1 li\u00ean quan kh\u00e1c.<\/p>\n\n\n\n

Ph\u00e1t hi\u1ec7n Thay \u0111\u1ed5i<\/em><\/strong>: So s\u00e1nh nhi\u1ec1u h\u00ecnh \u1ea3nh \u0111\u01b0\u1ee3c thu th\u1eadp t\u1ea1i c\u00e1c th\u1eddi \u0111i\u1ec3m kh\u00e1c nhau c\u00f3 th\u1ec3 gi\u00fap x\u00e1c \u0111\u1ecbnh c\u00e1c thay \u0111\u1ed5i trong khu v\u1ef1c nghi\u00ean c\u1ee9u. C\u00e1c k\u1ef9 thu\u1eadt ph\u00e1t hi\u1ec7n thay \u0111\u1ed5i c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 ph\u00e1t hi\u1ec7n s\u1ef1 thay \u0111\u1ed5i trong th\u1ef1c ph\u1ee7, ph\u00e1t tri\u1ec3n \u0111\u00f4 th\u1ecb, s\u1ee9c kh\u1ecfe th\u1ef1c v\u1eadt ho\u1eb7c c\u00e1c hi\u1ec7n t\u01b0\u1ee3ng kh\u00e1c.<\/p>\n\n\n\n

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Thay \u0111\u1ed5i v\u1ec1 th\u1ef1c ph\u1ee7 (land cover) \u1edf khu v\u1ef1c Tanguar Haor (Bangladhesh) t\u1eeb 1980 \u0111\u1ebfn 2010<\/figcaption><\/figure>\n\n\n\n

Ph\u00e2n t\u00edch Kh\u00f4ng gian<\/em><\/strong>: Th\u1ef1c hi\u1ec7n ph\u00e2n t\u00edch kh\u00f4ng gian \u0111\u1ec3 kh\u00e1m ph\u00e1 m\u1ed1i quan h\u1ec7 v\u00e0 xu h\u01b0\u1edbng trong d\u1eef li\u1ec7u vi\u1ec5n th\u00e1m. \u0110i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 bao g\u1ed3m vi\u1ec7c ch\u1ed3ng l\u1edbp d\u1eef li\u1ec7u, t\u00ednh to\u00e1n s\u1ed1 li\u1ec7u th\u1ed1ng k\u00ea, th\u1ef1c hi\u1ec7n m\u00f4 h\u00ecnh h\u00f3a kh\u00f4ng gian ho\u1eb7c th\u1ef1c hi\u1ec7n n\u1ed9i suy kh\u00f4ng gian.<\/p>\n\n\n\n

Ki\u1ec3m ch\u1ee9ng v\u00e0 \u0110\u00e1nh gi\u00e1 \u0110\u1ed9 ch\u00ednh x\u00e1c<\/em><\/strong>: \u0110\u00e1nh gi\u00e1 \u0111\u1ed9 ch\u00ednh x\u00e1c c\u1ee7a k\u1ebft qu\u1ea3 ph\u00e2n t\u00edch th\u00f4ng qua vi\u1ec7c so s\u00e1nh d\u1eef li\u1ec7u th\u1ef1c \u0111\u1ecba ho\u1eb7c d\u1eef li\u1ec7u tham chi\u1ebfu v\u1edbi th\u00f4ng tin \u0111\u01b0\u1ee3c thu \u0111\u01b0\u1ee3c t\u1eeb vi\u1ec5n th\u00e1m. B\u01b0\u1edbc n\u00e0y quan tr\u1ecdng \u0111\u1ec3 \u0111\u00e1nh gi\u00e1 t\u00ednh \u0111\u00e1ng tin c\u1eady v\u00e0 ch\u1ea5t l\u01b0\u1ee3ng c\u1ee7a ph\u00e2n t\u00edch c\u1ee7a b\u1ea1n.<\/p>\n\n\n\n

Di\u1ec5n gi\u1ea3i v\u00e0 Tr\u1ef1c quan h\u00f3a<\/em><\/strong>: Cu\u1ed1i c\u00f9ng, di\u1ec5n gi\u1ea3i d\u1eef li\u1ec7u vi\u1ec5n th\u00e1m \u0111\u00e3 ph\u00e2n t\u00edch \u0111\u1ec3 thu \u0111\u01b0\u1ee3c th\u00f4ng tin v\u00e0 r\u00fat ra k\u1ebft lu\u1eadn. Tr\u1ef1c quan h\u00f3a k\u1ebft qu\u1ea3 b\u1eb1ng c\u00e1ch s\u1eed d\u1ee5ng b\u1ea3n \u0111\u1ed3, bi\u1ec3u \u0111\u1ed3 ho\u1eb7c c\u00e1c bi\u1ec3u hi\u1ec7n h\u00ecnh \u1ea3nh kh\u00e1c \u0111\u1ec3 truy\u1ec1n \u0111\u1ea1t hi\u1ec7u qu\u1ea3 nh\u1eefng ph\u00e1t hi\u1ec7n c\u1ee7a b\u1ea1n.<\/p>\n\n\n\n

C\u00e1c k\u1ef9 thu\u1eadt v\u00e0 c\u00f4ng c\u1ee5 c\u1ee5 th\u1ec3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng cho ph\u00e2n t\u00edch d\u1eef li\u1ec7u vi\u1ec5n th\u00e1m c\u00f3 th\u1ec3 thay \u0111\u1ed5i t\u00f9y thu\u1ed9c v\u00e0o ph\u1ea7n m\u1ec1m, lo\u1ea1i d\u1eef li\u1ec7u v\u00e0 m\u1ee5c ti\u00eau c\u1ee7a nghi\u00ean c\u1ee9u. Quan tr\u1ecdng l\u00e0 hi\u1ec3u r\u00f5 nguy\u00ean t\u1eafc c\u1ee7a vi\u1ec5n th\u00e1m v\u00e0 c\u00f3 th\u1ec3 truy c\u1eadp v\u00e0o ph\u1ea7n m\u1ec1m ho\u1eb7c ng\u00f4n ng\u1eef l\u1eadp tr\u00ecnh ph\u00f9 h\u1ee3p th\u00f4ng d\u1ee5ng trong l\u0129nh v\u1ef1c n\u00e0y, nh\u01b0 ENVI, ArcGIS, QGIS ho\u1eb7c c\u00e1c th\u01b0 vi\u1ec7n Python nh\u01b0 GDAL.<\/p>\n\n\n\n

Ngu\u1ed3n:<\/em><\/p>\n\n\n\n

    \n
  1. http:\/\/www.geo-informatie.nl\/courses\/grs10306\/Clevers\/RS%20CH4%20Preprocessing\/RS%20Ch%204%20RS%20Preprocessing.pdf<\/li>\n\n\n\n
  2. https:\/\/seos-project.eu\/remotesensing\/remotesensing-c06-p03.html<\/li>\n\n\n\n
  3. https:\/\/www.atomaviation.com\/change-detection-remote-sensing\/<\/li>\n<\/ol>","protected":false},"excerpt":{"rendered":"

    Ph\u00e2n t\u00edch d\u1eef li\u1ec7u t\u1eeb vi\u1ec5n th\u00e1m li\u00ean quan \u0111\u1ebfn vi\u1ec7c th\u1ef1c hi\u1ec7n m\u1ed9t s\u1ed1 b\u01b0\u1edbc nh\u1eb1m tr\u00edch xu\u1ea5t th\u00f4ng tin c\u00f3 \u00fd ngh\u0129a t\u1eeb h\u00ecnh \u1ea3nh… <\/p>","protected":false},"author":2,"featured_media":3454,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[53,10,16,11],"class_list":["post-3452","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-vien-tham-share","tag-quan-sat-trai-dat","tag-remote-sensing","tag-ve-tinh","tag-vien-tham"],"_links":{"self":[{"href":"https:\/\/opengis.vn\/en\/wp-json\/wp\/v2\/posts\/3452","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/opengis.vn\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/opengis.vn\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/opengis.vn\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/opengis.vn\/en\/wp-json\/wp\/v2\/comments?post=3452"}],"version-history":[{"count":2,"href":"https:\/\/opengis.vn\/en\/wp-json\/wp\/v2\/posts\/3452\/revisions"}],"predecessor-version":[{"id":3457,"href":"https:\/\/opengis.vn\/en\/wp-json\/wp\/v2\/posts\/3452\/revisions\/3457"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/opengis.vn\/en\/wp-json\/wp\/v2\/media\/3454"}],"wp:attachment":[{"href":"https:\/\/opengis.vn\/en\/wp-json\/wp\/v2\/media?parent=3452"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/opengis.vn\/en\/wp-json\/wp\/v2\/categories?post=3452"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/opengis.vn\/en\/wp-json\/wp\/v2\/tags?post=3452"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}