Updated:
14 June 2006
MODIS - Moderate Resolution Imaging Spectroradiometer
MODIS (Moderate Resolution Imaging Spectroradiometer) is the key instrument aboard the satellites Terra (EOS AM-1), launched on 18 December 1999, and Aqua (EOS PM-1) (pictured right), launched on 4 May 2002. MODIS views almost the entire surface of the Earth every day, acquiring data in 36 spectral bands over a 2330 km swath.
MODIS data will improve the understanding of global dynamics and processes occurring on the land, in the oceans, and in the lower atmosphere. MODIS is playing a vital role in the development of validated, global, interactive Earth system models able to predict global change accurately enough to assist policy makers in making sound decisions concerning the protection of our environment.
ACRES has been acquiring MODIS data since August 2000. More information about how MODIS data can be used is available from NASA's MODIS Brochure, [the Brochure is available from this linked page - note it is in pdf format and 27Mb]
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Spacecraft Parameters
Spacecraft Characteristics
| Orbit: |
705 km, 10:30 a.m. descending node (Terra) or 1:30 p.m. ascending node (Aqua), sun-synchronous, near-polar, circular |
| Scan Rate: |
20.3 rpm, cross track |
| Swath Dimensions: |
2330 km (cross track) by 10 degrees of latitude (along track at nadir) |
| Telescope: |
17.78 cm diam. off-axis, afocal (collimated), with intermediate field stop |
| Size: |
1.0 × 1.6 × 1.0 m |
| Weight: |
228.7 kg |
| Power: |
162.5 W (single orbit average) |
| Data Rate: |
10.6 Mbps (peak daytime); 6.1 Mbps (orbital average) |
| Quantization: |
12 bits |
| Spatial Resolution: |
250 m (bands 1-2)
500 m (bands 3-7)
1000 m (bands 8-36) |
| Design Life: |
6 years |
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Sensor Characteristics
| Primary Use |
Band |
Bandwidth¹ |
Spectral
Radiance² |
Required
SNR³ |
Land/Cloud/Aerosols
Boundaries |
1 |
620 - 670 |
21.8 |
128 |
| 2 |
841 - 876 |
24.7 |
201 |
Land/Cloud/Aerosols
Properties |
3 |
459 - 479 |
35.3 |
243 |
| 4 |
545 - 565 |
29.0 |
228 |
| 5 |
1230 - 1250 |
5.4 |
74 |
| 6 |
1628 - 1652 |
7.3 |
275 |
| 7 |
2105 - 2155 |
1.0 |
110 |
Ocean Color
Phytoplankton
Biogeochemistry |
8 |
405 - 420 |
44.9 |
880 |
| 9 |
438 - 448 |
41.9 |
838 |
| 10 |
483 - 493 |
32.1 |
802 |
| 11 |
526 - 536 |
27.9 |
754 |
| 12 |
546 - 556 |
21.0 |
750 |
| 13 |
662 - 672 |
9.5 |
910 |
| 14 |
673 - 683 |
8.7 |
1087 |
| 15 |
743 - 753 |
10.2 |
586 |
| 16 |
862 - 877 |
6.2 |
516 |
Atmospheric
Water Vapor |
17 |
890 - 920 |
10.0 |
167 |
| 18 |
931 - 941 |
3.6 |
57 |
| 19 |
915 - 965 |
15.0 |
250 |
| Primary Use |
Band |
Bandwidth¹ |
Spectral
Radiance² |
Required
NE[delta]T(K)4 |
Surface/Cloud
Temperature |
20 |
3.660 - 3.840 |
0.45 (300K) |
0.05 |
| 21 |
3.929 - 3.989 |
2.38 (335K) |
2.00 |
| 22 |
3.929 - 3.989 |
0.67 (300K) |
0.07 |
| 23 |
4.020 - 4.080 |
0.79 (300K) |
0.07 |
Atmospheric
Temperature |
24 |
4.433 - 4.498 |
0.17 (250K) |
0.25 |
| 25 |
4.482 - 4.549 |
0.59 (275K) |
0.25 |
Cirrus Clouds
Water Vapor |
26 |
1.360 - 1.390 |
6.00 |
150(SNR) |
| 27 |
6.535 - 6.895 |
1.16 (240K) |
0.25 |
| 28 |
7.175 - 7.475 |
2.18 (250K) |
0.25 |
| Cloud Properties |
29 |
8.400 - 8.700 |
9.58 (300K) |
0.05 |
| Ozone |
30 |
9.580 - 9.880 |
3.69 (250K) |
0.25 |
Surface/Cloud
Temperature |
31 |
10.780 - 11.280 |
9.55 (300K) |
0.05 |
| 32 |
11.770 - 12.270 |
8.94 (300K) |
0.05 |
Cloud Top
Altitude |
33 |
13.185 - 13.485 |
4.52 (260K) |
0.25 |
| 34 |
13.485 - 13.785 |
3.76 (250K) |
0.25 |
| 35 |
13.785 - 14.085 |
3.11 (240K) |
0.25 |
| 36 |
14.085 - 14.385 |
2.08 (220K) |
0.35 |
* Footnotes:
1 Bands 1 to 19 are in nm; Bands 20 to 36 are in µm
2 Spectral Radiance values are (W/m² -µm-sr)
3 SNR = Signal-to-noise ratio
4 NE(delta)T = Noise-equivalent temperature difference |
| Note: Performance goal is 30-40% better than required. |
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Accessing MODIS data
Details on MODIS product specifications are available from MODIS Product and Download Information. Recent data (less than one week old) is available free of charge from the ACRES FTP site. Archiving of MODIS data commenced in May 2000.
Enquiries
For further information, please contact ACRES Customer Services on (02) 6249 9779.
Trading conditions
Special copyright conditions apply to the sale of satellite data. In order to purchase satellite data products, users must agree to the licence conditions covering its use. See ACRES End-User Licence Agreements.
