Moderate Resolution Imaging Spectroradiometer

Ash plumes on Kamchatka Peninsula, eastern Russia

Hurricane Katrina near Florida peninsula

MODIS (Moderate-resolution Imaging Spectroradiometer) is a payload scientific instrument launched into Earth orbit by NASA in 1999 on board the Terra (EOS AM) Satellite, and in 2002 on board the Aqua (EOS PM) satellite. The instruments capture data in 36 spectral bands ranging in wavelength from 0.4 µm to 14.4 µm and at varying spatial resolutions (2 bands at 250 m, 5 bands at 500 m and 29 bands at 1 km). Together the instruments image the entire Earth every 1 to 2 days. They are designed to provide measurements in large-scale global dynamics including changes in Earth's cloud cover, radiation budget and processes occurring in the oceans, on land, and in the lower atmosphere. Three on-board calibrators (a solar diffuser combined with a solar diffuser stability monitor, a spectral radiometric calibration assembly, and a blackbody) provide in-flight calibration.

Specifications
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	2330 km (cross track) by 10 km (along track at nadir)
Dimensions
Telescope	17.78 cm diam. off-axis, afocal (collimated), with intermediate field stop
Size	1.0 x 1.6 x 1.0 m
Weight	228.7 kg
Power	162.5 W (single orbit average)
Data Rate	10.6 Mbit/s (peak daytime); 6.1 Mbit/s (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

Solar irradiance spectrum and MODIS bands.

MODIS has used the Marine Optical Buoy for vicarious calibration.

MODIS Bands

Band	Wavelength (nm)	Resolution (m)	Primary Use
1	620-672	250m	Land/Cloud/Aerosols Boundaries
2	841-890	250m
3	459-479	500m	Land/Cloud/Aerosols Properties
4	545-565	500m
5	1230-1250	500m
6	1628-1652	500m
7	2105-2155	500m
8	405-420	1000m	Ocean Color/ Phytoplankton/ Biogeochemistry
9	438-448	1000m
10	483-493	1000m
11	526-536	1000m
12	546-556	1000m
13	662-672	1000m
14	673-683	1000m
15	743-753	1000m
16	862-877	1000m
17	890-920	1000m	Atmospheric Water Vapor
18	931-941	1000m
19	915-965	1000m
Band	Wavelength (µm)	Resolution (m)	Primary Use
20	3.660-3.840	1000m	Surface/Cloud Temperature
21	3.929-3.989	1000m
22	3.929-3.989	1000m
23	4.020-4.080	1000m
24	4.433-4.498	1000m	Atmospheric Temperature
25	4.482-4.549	1000m
26	1.360-1.390	1000m	Cirrus Clouds Water Vapor
27	6.535-6.895	1000m
28	7.175-7.475	1000m
29	8.400-8.700	1000m	Cloud Properties
30	9.580-9.880	1000m	Ozone
31	10.780-11.280	1000m	Surface/Cloud Temperature
32	11.770-12.270	1000m
33	13.185-13.485	1000m	Cloud Top Altitude
34	13.485-13.785	1000m
35	13.785-14.085	1000m
36	14.085-14.385	1000m

MODIS data availability

Raw MODIS data stream could be received in real-time using a tracking antenna, thanks to the instrument's direct broadcast capability .

Alternatively, the scientific data is made available to the public via several World Wide Web sites, such as:

• WIST — Warehouse Inventory Search Tool;
• LAADS Web — Level 1 and Atmosphere Archive and Distribution System (LAADS) web interface.

Most of the data is available in the HDF-EOS format — a variant of Hierarchical Data Format prescribed for the data derived from Earth Observing System missions .

See also

• Imaging spectroscopy
• NASA World Wind

External links

• Official NASA site
• MODIS bands and spectral ranges
• MODIS Images of the Day
• MODIS Land Product Subsetting Tool for North America from Oak Ridge National Laboratory
• MODIS Rapid Response system (Near Real Time images)
• NASA OnEarth (Web service for MODIS imagery)
• Visible Earth: Latest MODIS images