Moderate-Resolution Imaging Spectroradiometer

Ash plumes on Kamchatka Peninsula, eastern Russia.
Hurricane Katrina near Florida peninsula.
California wildfires.
Solar irradiance spectrum and MODIS bands.
External view of the MODIS unit.
Exploded view of the MODIS subsystems.
Detailed, photo-like view of Earth is based largely on observations from MODIS.

The Moderate-resolution Imaging Spectroradiometer (MODIS) 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 black body) provide in-flight calibration. MODIS has used the Marine Optical Buoy for vicarious calibration.

The MODIS Characterization Support Team (MCST) is dedicated to the production of high quality MODIS calibrated product which is a precursor to every geophysical science product. A detailed description of the MCST mission statement and other details can be found at MCST Web.[1]

Applications

One major use of MODIS data is for detection and mapping of wildland fires in the United States. The United States Forest Service's Remote Sensing Applications Center analyzes MODIS imagery on a continuous basis to provide information for the management and suppression of wildfires.[2]

MODIS has also been used to track changes in water levels on large bodies of water, such as the Aral Sea.[3]

Specifications

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

MODIS Bands

Band Wavelength
(nm)		 Resolution
(m)		 Primary Use
1 620–670 250 Land/Cloud/Aerosols
Boundaries
2 841–876 250
3 459–479 500 Land/Cloud/Aerosols
Properties
4 545–565 500
5 1230–1250 500
6 1628–1652 500
7 2105–2155 500
8 405–420 1000 Ocean Color/
Phytoplankton/
Biogeochemistry
9 438–448 1000
10 483–493 1000
11 526–536 1000
12 546–556 1000
13 662–672 1000
14 673–683 1000
15 743–753 1000
16 862–877 1000
17 890–920 1000 Atmospheric
Water Vapor
18 931–941 1000
19 915–965 1000
Band Wavelength
(µm)		 Resolution
(m)		 Primary Use
20 3.660–3.840 1000 Surface/Cloud
Temperature
21 3.929–3.989 1000
22 3.929–3.989 1000
23 4.020–4.080 1000
24 4.433–4.498 1000 Atmospheric
Temperature
25 4.482–4.549 1000
26 1.360–1.390 1000 Cirrus Clouds
Water Vapor
27 6.535–6.895 1000
28 7.175–7.475 1000
29 8.400–8.700 1000 Cloud Properties
30 9.580–9.880 1000 Ozone
31 10.780–11.280 1000 Surface/Cloud
Temperature
32 11.770–12.270 1000
33 13.185–13.485 1000 Cloud Top
Altitude
34 13.485–13.785 1000
35 13.785–14.085 1000
36 14.085–14.385 1000

MODIS data

MODIS Level 3 datasets

The following MODIS Level 3 (L3) datasets are available from NASA, as processed by the Collection 5 software.[4]

Daily 8-day 16-day 32-day Monthly Yearly Grid Platform Description
MxD08_D3 MxD08_E3 — — MxD08_M3 — 1° CMG Terra, Aqua Aerosol, Cloud Water Vapor, Ozone
MxD10A1 MxD10A2 — — — — 500 m SIN Terra, Aqua Snow Cover
MxD11A1 MxD11A2 — — — — 1000 m SIN Terra, Aqua Land Surface Temperature/Emissivity
MxD11B1 — — — — — 6000 m SIN Terra, Aqua Land Surface Temperature/Emissivity
MxD11C1 MxD11C2 — — MxD11C3 — 0.05° CMG Terra, Aqua Land Surface Temperature/Emissivity
— — MxD13C1 — MxD13C2 — 0.05° CMG Terra, Aqua Vegetation Indices
MxD14A1 MxD14A2 — — — — 1000 m SIN Terra, Aqua Thermal Anomalies, Fire
— — — — MCD45A1 — 500 m SIN Terra+Aqua Burned Area
250 m SIN 500 m SIN 1000 m SIN 0.05° CMG 1° CMG Time window Platform Description
MxD09Q1 MxD09A1 — — — 8-day Terra, Aqua Surface Reflectance
— — — MxD09CMG — Daily Terra, Aqua Surface Reflectance
— MCD12Q1 — MCD12C1 — Yearly Terra+Aqua Land Cover Type
— MCD12Q2 — — — Yearly Terra+Aqua Land Cover Dynamics

(Global Vegetation Phenology)

MxD13Q1 MxD13A1 MxD13A2 MxD13C1 — 16-day Terra, Aqua Vegetation Indices
— — MxD13A3 MxD13C2 — Monthly Terra, Aqua Vegetation Indices
— MCD43A1 MCD43B1 MCD43C1 — 16-day Terra+Aqua BRDF/Albedo Model Parameters
— MCD43A3 MCD43B3 MCD43C3 — 16-day Terra+Aqua Albedo
— MCD43A4 MCD43B4 MCD43C4 — 16-day Terra+Aqua Nadir BRDF-Adjusted Reflectance

Availability

Raw MODIS data stream could be received in real-time using a tracking antenna, thanks to the instrument's direct broadcast capability.[5]

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

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.[8]

Image based on observations from MODIS.

See also

References

  1. ↑ MCST Web
  2. ↑ "MODIS Active Fire Mapping Program FAQs." United States Forest Service. Retrieved: 30 September 2014.
  3. ↑ "Shrinking Aral Sea."NASA Earth Observatory. Retrieved: 30 September 2014.
  4. ↑ "MODIS Products Table". Retrieved 2011-06-12.
  5. ↑ "Direct Broadcast at MODIS Website". Retrieved 2009-06-02.
  6. ↑ "About Reverb". Retrieved 2011-11-07.
  7. ↑ "LANCE-MODIS". NASA Goddard Space Flight Center. Retrieved 2014-09-15.
  8. ↑ "HDF-EOS Tools and Information Center". Retrieved 2009-06-02.

External links

Wikimedia Commons has media related to NASA MODIS images.