{"id":3405,"date":"2023-12-20T10:00:00","date_gmt":"2023-12-20T03:00:00","guid":{"rendered":"https:\/\/opengis.vn\/?p=3405"},"modified":"2024-03-28T09:15:55","modified_gmt":"2024-03-28T02:15:55","slug":"anh-vien-tham-aster-va-huong-dan-tai-anh-aster-gdem","status":"publish","type":"post","link":"https:\/\/opengis.vn\/en\/blog\/anh-vien-tham-aster-va-huong-dan-tai-anh-aster-gdem\/","title":{"rendered":"\u1ea2nh vi\u1ec5n th\u00e1m ASTER v\u00e0 h\u01b0\u1edbng d\u1eabn t\u1ea3i \u1ea3nh ASTER GDEM"},"content":{"rendered":"

Gi\u1edbi thi\u1ec7u v\u1ec1 \u1ea3nh vi\u1ec5n th\u00e1m ASTER<\/mark><\/h3>\n\n\n\n

ASTER <\/strong><\/mark>– M\u00e1y \u0111o b\u1ee9c x\u1ea1 ph\u1ea3n x\u1ea1 v\u00e0 ph\u00e1t x\u1ea1 nhi\u1ec7t ti\u00ean ti\u1ebfn trong kh\u00f4ng gian (The Advanced Spaceborne Thermal Emission and Reflection Radiometer) l\u00e0 m\u1ed9t thi\u1ebft b\u1ecb vi\u1ec5n th\u00e1m c\u1ee7a Nh\u1eadt B\u1ea3n<\/strong> tr\u00ean v\u1ec7 tinh Terra <\/strong>\u0111\u01b0\u1ee3c NASA <\/strong>ph\u00f3ng v\u00e0o n\u0103m 1999<\/strong>. N\u00f3 \u0111\u00e3 thu th\u1eadp d\u1eef li\u1ec7u t\u1eeb th\u00e1ng 2 n\u0103m 2000.<\/p>\n\n\n

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H\u00ecnh 1. C\u1ea3m bi\u1ebfn ASTER g\u1eafn tr\u00ean v\u1ec7 tinh Terra.
Ngu\u1ed3n: NASA.<\/figcaption><\/figure>\n<\/div>\n\n\n

Thi\u1ebft b\u1ecb ASTER \u0111\u01b0\u1ee3c ch\u1ebf t\u1ea1o t\u1ea1i Nh\u1eadt B\u1ea3n<\/strong> do B\u1ed9 Kinh t\u1ebf, Th\u01b0\u01a1ng m\u1ea1i v\u00e0 C\u00f4ng nghi\u1ec7p (METI). Nh\u00f3m khoa h\u1ecdc chung c\u1ee7a Hoa K\u1ef3\/Nh\u1eadt B\u1ea3n ch\u1ecbu tr\u00e1ch nhi\u1ec7m thi\u1ebft k\u1ebf, hi\u1ec7u chu\u1ea9n v\u00e0 x\u00e1c nh\u1eadn d\u1eef li\u1ec7u c\u1ee7a thi\u1ebft b\u1ecb.<\/p>\n\n\n\n

ASTER <\/strong>cung c\u1ea5p h\u00ecnh \u1ea3nh c\u00f3 \u0111\u1ed9 ph\u00e2n gi\u1ea3i cao v\u1ec1 Tr\u00e1i \u0111\u1ea5t \u1edf 14 d\u1ea3i ph\u1ed5 \u0111i\u1ec7n t\u1eeb kh\u00e1c nhau<\/strong>, t\u1eeb \u00e1nh s\u00e1ng nh\u00ecn th\u1ea5y \u0111\u1ebfn tia h\u1ed3ng ngo\u1ea1i nhi\u1ec7t<\/strong>. \u0110\u1ed9 ph\u00e2n gi\u1ea3i<\/strong> c\u1ee7a h\u00ecnh \u1ea3nh n\u1eb1m trong kho\u1ea3ng t\u1eeb 15 \u0111\u1ebfn 90 m\u00e9t<\/strong>. D\u1eef li\u1ec7u ASTER \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 t\u1ea1o b\u1ea3n \u0111\u1ed3 chi ti\u1ebft v\u1ec1 nhi\u1ec7t \u0111\u1ed9 b\u1ec1 m\u1eb7t \u0111\u1ea5t, \u0111\u1ed9 ph\u00e1t x\u1ea1, \u0111\u1ed9 ph\u1ea3n x\u1ea1 v\u00e0 \u0111\u1ed9 cao<\/strong>.<\/p>\n\n\n\n

Kh\u1ea3 n\u0103ng ASTER ho\u1ea1t \u0111\u1ed9ng nh\u01b0 m\u1ed9t \u1ed1ng k\u00ednh ‘thu ph\u00f3ng’ cho c\u00e1c thi\u1ebft b\u1ecb Terra kh\u00e1c \u0111\u1eb7c bi\u1ec7t quan tr\u1ecdng \u0111\u1ec3 ph\u00e1t hi\u1ec7n thay \u0111\u1ed5i, hi\u1ec7u chu\u1ea9n\/x\u00e1c nh\u1eadn v\u00e0 nghi\u00ean c\u1ee9u b\u1ec1 m\u1eb7t \u0111\u1ea5t. Kh\u00f4ng gi\u1ed1ng nh\u01b0 c\u00e1c thi\u1ebft b\u1ecb kh\u00e1c tr\u00ean t\u00e0u Terra, ASTER <\/strong>s\u1ebd kh\u00f4ng thu th\u1eadp d\u1eef li\u1ec7u li\u00ean t\u1ee5c; \u0111\u00fang h\u01a1n, n\u00f3 thu th\u1eadp trung b\u00ecnh 8 ph\u00fat d\u1eef li\u1ec7u tr\u00ean m\u1ed7i qu\u1ef9 \u0111\u1ea1o<\/strong>. C\u1ea3 ba k\u00ednh thi\u00ean v\u0103n ASTER (VNIR, SWIR v\u00e0 TIR)<\/strong> \u0111\u1ec1u c\u00f3 th\u1ec3 \u0111\u1ecbnh h\u01b0\u1edbng theo h\u01b0\u1edbng \u0111\u01b0\u1eddng ch\u00e9o. V\u1edbi \u0111\u1ed9 ph\u00e2n gi\u1ea3i cao v\u00e0 kh\u1ea3 n\u0103ng thay \u0111\u1ed5i g\u00f3c nh\u00ecn, ASTER t\u1ea1o ra h\u00ecnh \u1ea3nh l\u1eadp th\u1ec3 v\u00e0 m\u00f4 h\u00ecnh \u0111\u1ed9 cao \u0111\u1ecba h\u00ecnh chi ti\u1ebft.<\/p>\n\n\n

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H\u00ecnh 2. Ba k\u00ednh thi\u00ean v\u0103n tr\u00ean c\u1ea3m bi\u1ebfn ASTER.
Ngu\u1ed3n: NASA.<\/figcaption><\/figure>\n<\/div>\n\n
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H\u00ecnh 3. Thi\u1ebft b\u1ecb ASTER – K\u00ednh thi\u00ean v\u0103n VNIR.
Ngu\u1ed3n: NASA.<\/figcaption><\/figure>\n<\/div>\n\n
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H\u00ecnh 4. Thi\u1ebft b\u1ecb ASTER – K\u00ednh thi\u00ean v\u0103n SWIR.
Ngu\u1ed3n: NASA.<\/figcaption><\/figure>\n<\/div>\n\n
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H\u00ecnh 5. Thi\u1ebft b\u1ecb ASTER – K\u00ednh thi\u00ean v\u0103n TIR.
Ngu\u1ed3n: NASA.<\/figcaption><\/figure>\n<\/div>\n\n\n
Th\u00f4ng tin<\/strong><\/th>N\u1ed9i dung<\/strong><\/th><\/tr><\/thead>
Qu\u1ef9 \u0111\u1ea1o<\/td>705 km, 10:30 s\u00e1ng theo chi\u1ec1u gi\u1ea3m d\u1ea7n (Terra), \u0111\u1ed3ng b\u1ed9 m\u1eb7t tr\u1eddi, g\u1ea7n c\u1ef1c, tr\u00f2n<\/td><\/tr>
L\u01b0\u1ee3ng t\u1eed h\u00f3a<\/td>D\u1eef li\u1ec7u d\u1ea1ng 8-12 bit<\/td><\/tr>
\u0110\u1ed9 nghi\u00eang qu\u1ef9 \u0111\u1ea1o<\/td>98.3 \u0111\u1ed9 t\u00ednh t\u1eeb x\u00edch \u0111\u1ea1o<\/td><\/tr>
Chu k\u1ef3 qu\u1ef9 \u0111\u1ea1o<\/td>98.88 ph\u00fat<\/td><\/tr>
\u0110\u1ed9 ph\u00e2n gi\u1ea3i kh\u00f4ng gian<\/td>3 \u0111\u1ed9 ph\u00e2n gi\u1ea3i<\/strong> t\u1eeb 0.52 \u03bcm \u0111\u1ebfn 11.65 \u03bcm v\u1edbi 14 d\u1ea3i ph\u1ed5<\/strong>:
+ VNIR:<\/strong> 15m<\/strong> (b\u0103ng t\u1ea7n 1\u20133N,B)
+ SWIR: 30m<\/strong> (b\u0103ng t\u1ea7n 4\u20139)
+ TIR:<\/strong> 90m<\/strong> (b\u0103ng t\u1ea7n 10\u201314)<\/td><\/tr>
Th\u1eddi gian cung c\u1ea5p \u1ea3nh<\/td>16 ng\u00e0y, t\u1ee9c l\u00e0 c\u1ee9 sau 16 ng\u00e0y (ho\u1eb7c 233 qu\u1ef9 \u0111\u1ea1o) m\u00f4 h\u00ecnh qu\u1ef9 \u0111\u1ea1o s\u1ebd t\u1ef1 l\u1eb7p l\u1ea1i<\/td><\/tr>
Tu\u1ed5i th\u1ecd thi\u1ebft k\u1ebf<\/td>1999 – Hi\u1ec7n t\u1ea1i<\/td><\/tr><\/tbody><\/table>
B\u1ea3ng 1: Th\u00f4ng tin chung c\u1ea3m bi\u1ebfn ASTER.<\/figcaption><\/figure>\n\n\n\n

Th\u00f4ng tin c\u00e1c band \u1ea3nh ASTER<\/strong> \u0111\u01b0\u1ee3c m\u00f4 t\u1ea3 trong b\u1ea3ng sau.<\/p>\n\n\n\n

Band<\/em>
K\u00eanh<\/th>		Band width (\u03bcm)<\/em>
\u0110\u1ed9 r\u1ed9ng b\u0103ng t\u1ea7n<\/th>		Shortwave\/S\u00f3ng ng\u1eafn<\/em><\/th>Resolution (m)<\/em>
\u0110\u1ed9 ph\u00e2n gi\u1ea3i<\/th><\/tr><\/thead>
1<\/td>0.520 \u2013 0.600<\/td>Green\/Yellow<\/em>
Xanh l\u1ee5c\/V\u00e0ng<\/td>		15<\/td><\/tr>
2<\/td>0.452 \u2013 0.512<\/td>Red <\/em>– \u0110\u1ecf<\/td>15<\/td><\/tr>
3N<\/td>0.760 \u2013 0.860<\/td>NIR<\/em> \u2013 Near InfraRed<\/em>
C\u1eadn h\u1ed3ng ngo\u1ea1i<\/td>		15<\/td><\/tr>
3B<\/td>0.760 \u2013 0.860<\/td>NIR<\/em> \u2013 Near InfraRed<\/em>
C\u1eadn h\u1ed3ng ngo\u1ea1i (Backward<\/em>)<\/td>		15<\/td><\/tr>
4<\/td>1.600 -1.700<\/td>Shortwave Infrared\/SWIR<\/em>
H\u1ed3ng ngo\u1ea1i s\u00f3ng ng\u1eafn<\/td>		30<\/td><\/tr>
5<\/td>2.145 \u2013 2185<\/td>Shortwave Infrared\/SWIR<\/em>
H\u1ed3ng ngo\u1ea1i s\u00f3ng ng\u1eafn<\/td>		30<\/td><\/tr>
6<\/td>2.185 \u2013 2.225<\/td>Shortwave Infrared\/SWIR<\/em>
H\u1ed3ng ngo\u1ea1i s\u00f3ng ng\u1eafn<\/td>		30<\/td><\/tr>
7<\/td>2.235 \u2013 2.285<\/td>Shortwave Infrared\/SWIR<\/em>
H\u1ed3ng ngo\u1ea1i s\u00f3ng ng\u1eafn<\/td>		30<\/td><\/tr>
8<\/td>2.295 \u2013 2.365<\/td>Shortwave Infrared\/SWIR<\/em>
H\u1ed3ng ngo\u1ea1i s\u00f3ng ng\u1eafn<\/td>		30<\/td><\/tr>
9<\/td>2.360 \u2013 2.430<\/td>Shortwave Infrared\/SWIR<\/em>
H\u1ed3ng ngo\u1ea1i s\u00f3ng ng\u1eafn<\/td>		30<\/td><\/tr>
10<\/td>8.125 \u2013 8.475<\/td>TIR \u2013 Thermal InfraRed<\/em>
H\u1ed3ng ngo\u1ea1i s\u00f3ng d\u00e0i\/H\u1ed3ng ngo\u1ea1i nhi\u1ec7t<\/td>		90<\/td><\/tr>
11<\/td>8.475 \u2013 8.825<\/td>TIR \u2013 Thermal InfraRed<\/em>
H\u1ed3ng ngo\u1ea1i s\u00f3ng d\u00e0i\/H\u1ed3ng ngo\u1ea1i nhi\u1ec7t<\/td>		90<\/td><\/tr>
12<\/td>8.925 \u2013 9.275<\/td>TIR \u2013 Thermal InfraRed<\/em>
H\u1ed3ng ngo\u1ea1i s\u00f3ng d\u00e0i\/H\u1ed3ng ngo\u1ea1i nhi\u1ec7t<\/td>		90<\/td><\/tr>
13<\/td>10.250 \u2013 10.950<\/td>TIR \u2013 Thermal InfraRed<\/em>
H\u1ed3ng ngo\u1ea1i s\u00f3ng d\u00e0i\/H\u1ed3ng ngo\u1ea1i nhi\u1ec7t<\/td>		90<\/td><\/tr>
14<\/td>10.950 \u2013 11.650<\/td>TIR \u2013 Thermal InfraRed<\/em>
H\u1ed3ng ngo\u1ea1i s\u00f3ng d\u00e0i\/H\u1ed3ng ngo\u1ea1i nhi\u1ec7t<\/td>		90<\/td><\/tr><\/tbody><\/table>
B\u1ea3ng 2. C\u00e1c band c\u1ee7a \u1ea3nh ASTER.<\/figcaption><\/figure>\n\n\n\n

\u1ea2nh m\u1eabu ASTER 15m – Las Vegas, Nevada.<\/p>\n\n\n

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H\u00ecnh 6. Las Vegas, Nevada – \u1ea2nh ASTER 15m.
Ngu\u1ed3n: Satellite Imaging Corporation.<\/figcaption><\/figure>\n<\/div>\n\n\n
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C\u00e1c \u1ee9ng d\u1ee5ng c\u1ee7a \u1ea3nh vi\u1ec5n th\u00e1m ASTER<\/mark><\/h3>\n\n\n\n

1.<\/strong> Land surface climatology – Kh\u00ed h\u1eadu b\u1ec1 m\u1eb7t \u0111\u1ea5t<\/strong>: \u0111i\u1ec1u tra c\u00e1c th\u00f4ng s\u1ed1 b\u1ec1 m\u1eb7t \u0111\u1ea5t, nhi\u1ec7t \u0111\u1ed9 b\u1ec1 m\u1eb7t, v.v., \u0111\u1ec3 hi\u1ec3u s\u1ef1 t\u01b0\u01a1ng t\u00e1c gi\u1eefa \u0111\u1ea5t v\u00e0 b\u1ec1 m\u1eb7t c\u0169ng nh\u01b0 c\u00e1c d\u00f2ng n\u0103ng l\u01b0\u1ee3ng v\u00e0 \u0111\u1ed9 \u1ea9m.<\/p>\n\n\n\n

2. Vegetation and ecosystem dynamics – \u0110\u1ed9ng l\u1ef1c h\u1ecdc c\u1ee7a th\u1ea3m th\u1ef1c v\u1eadt v\u00e0 h\u1ec7 sinh th\u00e1i<\/strong>: nghi\u00ean c\u1ee9u v\u1ec1 s\u1ef1 ph\u00e2n b\u1ed1 c\u1ee7a th\u1ea3m th\u1ef1c v\u1eadt v\u00e0 \u0111\u1ea5t c\u0169ng nh\u01b0 nh\u1eefng thay \u0111\u1ed5i c\u1ee7a ch\u00fang \u0111\u1ec3 \u01b0\u1edbc t\u00ednh n\u0103ng su\u1ea5t sinh h\u1ecdc, t\u00ecm hi\u1ec3u s\u1ef1 t\u01b0\u01a1ng t\u00e1c gi\u1eefa \u0111\u1ea5t v\u00e0 kh\u00ed quy\u1ec3n v\u00e0 ph\u00e1t hi\u1ec7n s\u1ef1 thay \u0111\u1ed5i c\u1ee7a h\u1ec7 sinh th\u00e1i.<\/p>\n\n\n\n

3. Volcano monitoring – Gi\u00e1m s\u00e1t n\u00fai l\u1eeda \u0111\u1ea1n<\/strong>: gi\u00e1m s\u00e1t c\u00e1c v\u1ee5 phun tr\u00e0o v\u00e0 c\u00e1c s\u1ef1 ki\u1ec7n b\u00e1o tr\u01b0\u1edbc, ch\u1eb3ng h\u1ea1n nh\u01b0 ph\u00e1t th\u1ea3i kh\u00ed, c\u00e1c \u0111\u1ee3t phun tr\u00e0o, s\u1ef1 ph\u00e1t tri\u1ec3n c\u1ee7a h\u1ed3 dung nham, l\u1ecbch s\u1eed phun tr\u00e0o v\u00e0 kh\u1ea3 n\u0103ng phun tr\u00e0o<\/p>\n\n\n\n

4.<\/strong> Hazard monitoring – Gi\u00e1m s\u00e1t m\u1ed1i nguy hi\u1ec3m<\/strong>: quan s\u00e1t m\u1ee9c \u0111\u1ed9 v\u00e0 \u1ea3nh h\u01b0\u1edfng c\u1ee7a ch\u00e1y r\u1eebng, l\u0169 l\u1ee5t, x\u00f3i m\u00f2n b\u1edd bi\u1ec3n, thi\u1ec7t h\u1ea1i do \u0111\u1ed9ng \u0111\u1ea5t v\u00e0 s\u00f3ng th\u1ea7n<\/p>\n\n\n\n

5.<\/strong> Hydrology – Th\u1ee7y v\u0103n<\/strong>: hi\u1ec3u bi\u1ebft v\u1ec1 c\u00e1c qu\u00e1 tr\u00ecnh th\u1ee7y v\u0103n v\u00e0 n\u0103ng l\u01b0\u1ee3ng to\u00e0n c\u1ea7u c\u0169ng nh\u01b0 m\u1ed1i quan h\u1ec7 c\u1ee7a ch\u00fang v\u1edbi s\u1ef1 thay \u0111\u1ed5i to\u00e0n c\u1ea7u; bao g\u1ed3m c\u1ea3 s\u1ef1 tho\u00e1t h\u01a1i n\u01b0\u1edbc t\u1eeb th\u1ef1c v\u1eadt<\/p>\n\n\n\n

6. Geology and soils – \u0110\u1ecba ch\u1ea5t v\u00e0 \u0111\u1ea5t<\/strong>: th\u00e0nh ph\u1ea7n chi ti\u1ebft v\u00e0 l\u1eadp b\u1ea3n \u0111\u1ed3 \u0111\u1ecba m\u1ea1o c\u1ee7a \u0111\u1ea5t b\u1ec1 m\u1eb7t v\u00e0 \u0111\u00e1 g\u1ed1c \u0111\u1ec3 nghi\u00ean c\u1ee9u c\u00e1c qu\u00e1 tr\u00ecnh b\u1ec1 m\u1eb7t \u0111\u1ea5t v\u00e0 l\u1ecbch s\u1eed tr\u00e1i \u0111\u1ea5t<\/p>\n\n\n\n

7. Land surface and land cover change – S\u1ef1 thay \u0111\u1ed5i b\u1ec1 m\u1eb7t \u0111\u1ea5t v\u00e0 \u0111\u1ed9 che ph\u1ee7 \u0111\u1ea5t<\/strong>: gi\u00e1m s\u00e1t t\u00ecnh tr\u1ea1ng sa m\u1ea1c h\u00f3a, ph\u00e1 r\u1eebng v\u00e0 \u0111\u00f4 th\u1ecb h\u00f3a; cung c\u1ea5p d\u1eef li\u1ec7u cho c\u00e1c nh\u00e0 qu\u1ea3n l\u00fd b\u1ea3o t\u1ed3n \u0111\u1ec3 gi\u00e1m s\u00e1t c\u00e1c khu b\u1ea3o t\u1ed3n, v\u01b0\u1eddn qu\u1ed1c gia v\u00e0 khu v\u1ef1c hoang d\u00e3.<\/p>\n\n\n\n

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ASTER Global Digital Elevation Model – M\u00f4 h\u00ecnh \u0111\u1ed9 cao s\u1ed1 to\u00e0n c\u1ea7u ASTER – GDEM<\/mark><\/h3>\n\n\n\n

ASTER Global Digital Elevation Model<\/strong> – M\u00f4 h\u00ecnh \u0111\u1ed9 cao s\u1ed1 to\u00e0n c\u1ea7u ASTER – GDEM \u0111\u00e3 \u0111\u01b0\u1ee3c ph\u00e1t h\u00e0nh ra c\u00f4ng ch\u00fang ng\u00e0y 29\/6\/2009<\/strong>. L\u00e0 m\u1ed9t h\u1ee3p t\u00e1c chung gi\u1eefa NASA v\u00e0 B\u1ed9 Kinh t\u1ebf, Th\u01b0\u01a1ng m\u1ea1i v\u00e0 C\u00f4ng nghi\u1ec7p Nh\u1eadt B\u1ea3n (METI), M\u00f4 h\u00ecnh \u0110\u1ed9 cao K\u1ef9 thu\u1eadt s\u1ed1 To\u00e0n c\u1ea7u l\u00e0 b\u1ea3n \u0111\u1ed3 ho\u00e0n ch\u1ec9nh nh\u1ea5t v\u1ec1 tr\u00e1i \u0111\u1ea5t t\u1eebng \u0111\u01b0\u1ee3c t\u1ea1o ra, bao ph\u1ee7 99 % b\u1ec1 m\u1eb7t c\u1ee7a n\u00f3. ASTER – GDEM g\u1ed3m 3 Version<\/strong>.<\/p>\n\n\n\n

Version 1<\/mark><\/h4>\n\n\n\n

Tr\u01b0\u1edbc \u0111\u00e2y, B\u1ea3n \u0111\u1ed3 to\u00e0n di\u1ec7n nh\u1ea5t l\u00e0 SRTM <\/strong>– Nhi\u1ec7m v\u1ee5 \u0110\u1ecba h\u00ecnh Radar Con thoi c\u1ee7a NASA (Shuttle Radar Topography Mission), bao ph\u1ee7 kho\u1ea3ng 80% b\u1ec1 m\u1eb7t Tr\u00e1i \u0111\u1ea5t<\/strong>, v\u1edbi \u0111\u1ed9 ph\u00e2n gi\u1ea3i to\u00e0n c\u1ea7u l\u00e0 90m\u00e9t<\/strong>, v\u00e0 \u0111\u1ed9 ph\u00e2n gi\u1ea3i 30m\u00e9t<\/strong> tr\u00ean kh\u1eafp Hoa K\u1ef3.<\/p>\n\n\n\n

GDEM <\/strong>bao ph\u1ee7 h\u00e0nh tinh t\u1eeb 83 \u0111\u1ed9 B\u1eafc \u0111\u1ebfn 83 \u0111\u1ed9 Nam<\/strong> (v\u01b0\u1ee3t qua ph\u1ea1m vi bao ph\u1ee7 c\u1ee7a SRTM t\u1eeb 56 \u00b0S \u0111\u1ebfn 60 \u00b0N), tr\u1edf th\u00e0nh h\u1ec7 th\u1ed1ng b\u1ea3n \u0111\u1ed3 tr\u00e1i \u0111\u1ea5t \u0111\u1ea7u ti\u00ean cung c\u1ea5p ph\u1ea1m vi bao ph\u1ee7 to\u00e0n di\u1ec7n v\u1ec1 c\u00e1c v\u00f9ng c\u1ef1c. N\u00f3 \u0111\u01b0\u1ee3c t\u1ea1o ra b\u1eb1ng c\u00e1ch t\u1ed5ng h\u1ee3p 1,3 tri\u1ec7u h\u00ecnh \u1ea3nh VNIR do ASTER ch\u1ee5p b\u1eb1ng k\u1ef9 thu\u1eadt t\u01b0\u01a1ng quan l\u1eadp th\u1ec3 m\u1ed9t l\u1ea7n v\u1edbi c\u00e1c ph\u00e9p \u0111o \u0111\u1ed9 cao \u0111\u1ecba h\u00ecnh<\/strong> \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n tr\u00ean to\u00e0n c\u1ea7u \u1edf kho\u1ea3ng c\u00e1ch 30<\/strong> m\u00e9t <\/strong>(98 ft).<\/p>\n\n\n\n

Tuy nhi\u00ean, m\u1eb7c d\u00f9 \u0111\u1ed9 ph\u00e2n gi\u1ea3i danh ngh\u0129a cao, m\u1ed9t s\u1ed1 nh\u00e0 \u0111\u00e1nh gi\u00e1 \u0111\u00e3 nh\u1eadn x\u00e9t r\u1eb1ng \u0111\u1ed9 ph\u00e2n gi\u1ea3i th\u1ef1c s\u1ef1 th\u1ea5p h\u01a1n \u0111\u00e1ng k\u1ec3 v\u00e0 kh\u00f4ng t\u1ed1t b\u1eb1ng \u0111\u1ed9 ph\u00e2n gi\u1ea3i c\u1ee7a d\u1eef li\u1ec7u SRTM v\u00ec xu\u1ea5t hi\u1ec7n 1 s\u1ed1 hi\u1ec7n t\u01b0\u1ee3ng h\u00ecnh gi\u1ea3. M\u1ed9t s\u1ed1 h\u1ea1n ch\u1ebf n\u00e0y \u0111\u00e3 \u0111\u01b0\u1ee3c METI v\u00e0 NASA x\u00e1c nh\u1eadn, h\u1ecd ch\u1ec9 ra r\u1eb1ng Version 1 c\u1ee7a s\u1ea3n ph\u1ea9m GDEM l\u00e0 “c\u1ea5p nghi\u00ean c\u1ee9u”.<\/p>\n\n\n\n

Version 2<\/mark><\/h4>\n\n\n\n

Trong th\u00e1ng 10 n\u0103m 2011<\/strong>, Version 2<\/strong> c\u1ee7a M\u00f4 h\u00ecnh \u0111\u1ed9 cao s\u1ed1 to\u00e0n c\u1ea7u (GDEM) \u0111\u00e3 \u0111\u01b0\u1ee3c ph\u00e1t h\u00e0nh c\u00f4ng khai. \u0110\u00e2y \u0111\u01b0\u1ee3c coi l\u00e0 m\u1ed9t c\u1ea3i ti\u1ebfn so v\u1edbi Version 1.<\/p>\n\n\n\n

Nh\u1eefng c\u1ea3i ti\u1ebfn n\u00e0y bao g\u1ed3m t\u0103ng \u0111\u1ed9 ch\u00ednh x\u00e1c theo chi\u1ec1u ngang v\u00e0 chi\u1ec1u d\u1ecdc, \u0111\u1ed9 ph\u00e2n gi\u1ea3i theo chi\u1ec1u ngang t\u1ed1t h\u01a1n<\/strong>, gi\u1ea3m s\u1ef1 hi\u1ec7n di\u1ec7n c\u1ee7a c\u00e1c \u0111\u1ed3 t\u1ea1o t\u00e1c v\u00e0 c\u00e1c gi\u00e1 tr\u1ecb th\u1ef1c t\u1ebf h\u01a1n tr\u00ean c\u00e1c v\u00f9ng n\u01b0\u1edbc.Tuy nhi\u00ean, m\u1ed9t ng\u01b0\u1eddi \u0111\u00e1nh gi\u00e1 v\u1eabn tr\u00e2n tr\u1ecdn t\u1eadp d\u1eef li\u1ec7u ASTER Version 2, m\u1eb7c d\u00f9 cho th\u1ea5y ‘s\u1ef1 c\u1ea3i thi\u1ec7n \u0111\u00e1ng k\u1ec3 v\u1ec1 m\u1ee9c \u0111\u1ed9 chi ti\u1ebft hi\u1ec7u qu\u1ea3’, v\u1eabn \u0111\u01b0\u1ee3c coi l\u00e0 ‘c\u1ea5p \u0111\u1ed9 th\u1eed nghi\u1ec7m ho\u1eb7c nghi\u00ean c\u1ee9u’ do s\u1ef1 hi\u1ec7n di\u1ec7n c\u1ee7a c\u00e1c h\u00ecnh gi\u1ea3 (artefact).<\/p>\n\n\n\n

M\u1ed9t nghi\u00ean c\u1ee9u n\u0103m 2014: Rexer, M.; Hirt, C. (2014). “Comparison of free high-resolution digital elevation data sets (ASTER GDEM2, SRTM v2.1\/v4.1) and validation against accurate heights from the Australian National Gravity Database<\/strong>” \u0111\u00e3 ch\u1ec9 ra r\u1eb1ng tr\u00ean \u0111\u1ecba h\u00ecnh \u0111\u1ed3i n\u00fai g\u1ed3 gh\u1ec1, b\u1ed9 d\u1eef li\u1ec7u ASTER Version 2 c\u00f3 th\u1ec3 th\u1ec3 hi\u1ec7n m\u1eb7t \u0111\u1ea5t ch\u00ednh x\u00e1c h\u01a1n so v\u1edbi m\u00f4 h\u00ecnh \u0111\u1ed9 cao SRTM<\/strong>.<\/p>\n\n\n\n

Version 3<\/mark><\/h4>\n\n\n\n

ASTER Version 3<\/strong> \u0111\u01b0\u1ee3c ph\u00e1t h\u00e0nh v\u00e0o ng\u00e0y 5 th\u00e1ng 8 n\u0103m 2019<\/strong>. GDEM V3 \u0111\u01b0\u1ee3c c\u1ea3i ti\u1ebfn b\u1ed5 sung th\u00eam c\u00e1c c\u1eb7p \u00e2m thanh n\u1ed5i b\u1ed5 sung, c\u1ea3i thi\u1ec7n v\u00f9ng ph\u1ee7 s\u00f3ng v\u00e0 gi\u1ea3m s\u1ef1 xu\u1ea5t hi\u1ec7n c\u1ee7a c\u00e1c hi\u1ec7n v\u1eadt.<\/p>\n\n\n\n

Thu\u1eadt to\u00e1n s\u1ea3n xu\u1ea5t tinh t\u1ebf gi\u00fap c\u1ea3i thi\u1ec7n \u0111\u1ed9 ph\u00e2n gi\u1ea3i kh\u00f4ng gian, t\u0103ng \u0111\u1ed9 ch\u00ednh x\u00e1c theo chi\u1ec1u ngang v\u00e0 chi\u1ec1u d\u1ecdc.<\/strong> ASTER GDEM V3 duy tr\u00ec \u0111\u1ecbnh d\u1ea1ng GeoTIFF v\u00e0 c\u1ea5u tr\u00fac l\u01b0\u1edbi v\u00e0 \u00f4 t\u01b0\u01a1ng t\u1ef1 nh\u01b0 V1 v\u00e0 V2, v\u1edbi c\u00e1c c\u1ed9t d\u00e0i 30 m\u00e9t v\u00e0 c\u00e1c \u00f4 1 x 1 \u0111\u1ed9.<\/p>\n\n\n\n

Version 3<\/strong> \u0111\u01b0\u1ee3c cho l\u00e0 c\u00f3 nh\u1eefng c\u1ea3i ti\u1ebfn \u0111\u00e1ng k\u1ec3 so v\u1edbi phi\u00ean b\u1ea3n tr\u01b0\u1edbc. Qu\u00e1 tr\u00ecnh x\u1eed l\u00fd t\u1ef1 \u0111\u1ed9ng 2,3 tri\u1ec7u c\u1ea3nh t\u1eeb kho l\u01b0u tr\u1eef ASTER \u0111\u00e3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 t\u1ea1o ASTER GDEM<\/strong>, bao g\u1ed3m t\u01b0\u01a1ng quan \u00e2m thanh n\u1ed5i \u0111\u1ec3 t\u1ea1o c\u00e1c ASTER DEM<\/strong> d\u1ef1a tr\u00ean c\u1ea3nh ri\u00eang l\u1ebb, che d\u1ea5u \u0111\u1ec3 lo\u1ea1i b\u1ecf c\u00e1c pixel m\u1edd, x\u1ebfp ch\u1ed3ng t\u1ea5t c\u1ea3 c\u00e1c DEM \u0111\u01b0\u1ee3c s\u00e0ng l\u1ecdc tr\u00ean \u0111\u00e1m m\u00e2y, lo\u1ea1i b\u1ecf c\u00e1c gi\u00e1 tr\u1ecb x\u1ea5u c\u00f2n s\u00f3t l\u1ea1i v\u00e0 c\u00e1c ngo\u1ea1i l\u1ec7, l\u1ea5y trung b\u00ecnh d\u1eef li\u1ec7u \u0111\u00e3 ch\u1ecdn \u0111\u1ec3 t\u1ea1o gi\u00e1 tr\u1ecb pixel cu\u1ed1i c\u00f9ng.<\/p>\n\n\n\n

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H\u00ecnh 7. \u1ea2nh ASTER GDEM to\u00e0n c\u1ea7u (S\u1ea3n ph\u1ea9m \u0111\u1ed9 ph\u00e2n gi\u1ea3i 10km).
Ngu\u1ed3n: NASA.<\/figcaption><\/figure>\n\n\n\n
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H\u00ecnh 8. \u1ea2nh ASTER GDEM Ch\u00e2u \u00c1 (S\u1ea3n ph\u1ea9m \u0111\u1ed9 ph\u00e2n gi\u1ea3i 10km).
Ngu\u1ed3n: NASA.<\/figcaption><\/figure>\n\n\n\n
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H\u00ecnh 9. \u1ea2nh ASTER GDEM \u0110\u00f4ng Nam \u00c1 (S\u1ea3n ph\u1ea9m \u0111\u1ed9 ph\u00e2n gi\u1ea3i 10km).
Ngu\u1ed3n: NASA.<\/figcaption><\/figure>\n\n\n\n
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H\u01b0\u1edbng d\u1eabn t\u1ea3i \u1ea3nh ASTER GDEM<\/mark><\/h3>\n\n\n\n

D\u1eef li\u1ec7u ASTER GDEM <\/strong>l\u00e0 ngu\u1ed3n d\u1eef li\u1ec7u mi\u1ec5n ph\u00ed<\/mark><\/strong> v\u00e0 \u0111\u01b0\u1ee3c t\u1ea3i t\u1eeb c\u00e1c ngu\u1ed3n d\u1eef li\u1ec7u sau:<\/p>\n\n\n\n

\u0110\u1ec3 t\u00ecm hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 c\u00e1ch t\u1ea3i \u1ea3nh ASTER, tham kh\u1ea3o th\u00eam c\u00e1ch b\u00e0i vi\u1ebft: “MODIS – H\u01b0\u1edbng d\u1eabn t\u1ea3i \u1ea3nh MODIS<\/a><\/strong>“.<\/p>\n\n\n\n

1. T\u1ea3i xu\u1ed1ng tr\u1ef1c ti\u1ebfp c\u00e1c t\u1ec7p ri\u00eang l\u1ebb th\u00f4ng qua Nh\u00f3m d\u1eef li\u1ec7u c\u1ee7a LP DAAC<\/a><\/mark><\/strong>.<\/p>\n\n\n

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H\u00ecnh 10. Giao di\u1ec7n t\u1ea3i \u1ea3nh ASTER c\u1ee7a LP DAAC.<\/figcaption><\/figure>\n<\/div>\n\n\n

2. T\u00ecm d\u1eef li\u1ec7u tr\u1ef1c ti\u1ebfp trong khu v\u1ef1c nghi\u00ean c\u1ee9u c\u1ee7a b\u1ea1n th\u00f4ng qua T\u00ecm ki\u1ebfm Earthdata c\u1ee7a NASA<\/a><\/mark><\/strong>.<\/p>\n\n\n

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H\u00ecnh 11. Giao di\u1ec7n t\u1ea3i \u1ea3nh ASTER c\u1ee7a Earthdata c\u1ee7a NASA.<\/figcaption><\/figure>\n<\/div>\n\n\n

3. H\u00ecnh dung ASTER GDEM tr\u00ean Tr\u00e1i \u0111\u1ea5t th\u00f4ng qua NASA WorldView<\/strong><\/a>.<\/p>\n\n\n

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H\u00ecnh 12. Giao di\u1ec7n t\u1ea3i \u1ea3nh ASTER c\u1ee7a WorldView.<\/figcaption><\/figure>\n<\/div>\n\n\n

4. ASTER GDEM c\u1ee7a Japan Space System<\/strong><\/a>.<\/p>\n\n\n

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H\u00ecnh 13. Giao di\u1ec7n t\u1ea3i \u1ea3nh ASTER c\u1ee7a Japan Space System.<\/figcaption><\/figure>\n<\/div>\n\n
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H\u00ecnh 14. K\u1ebft qu\u1ea3 \u1ea3nh ASTER GDEM t\u1ea3i t\u1eeb LP DAAC xu\u1ed1ng.<\/figcaption><\/figure>\n<\/div>\n\n\n
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Ngu\u1ed3n tham kh\u1ea3o<\/mark><\/strong><\/p>\n\n\n\n