MODIS Moderate Resolution Imaging Spectroradiometer

Despite popular belief that MODIS is a satellite, it’s actually an instrument onboard a satellite.

MODIS stands for Moderate Resolution Imaging Spectroradiometer. It has 36 spectral bands, 250-1000 meter resolution, and averages a 2-day revisit period.

Because of this versatility, MODIS has changed how we understand our land, ocean, and atmosphere. And due to its enormous coverage, it enables us to monitor activities such as active fires, land use change, and volcanic activity.

Let’s dive right in and explore MODIS bands, resolution, and temporal frequency.

MODIS Uses and Applications

Since its launch, MODIS had been referred to as the quintessential instrument of Earth Observation. This is because it covers more ground, and captures more spectral bands with higher temporal frequency.

For example, it collects essential data about land, ocean, and atmosphere about every 2 days. In these 3 examples below, we just barely scratch the surface of the applications and uses of MODIS imagery.

Fire and Hot Spot Detection
Active Forest Fires

The fire detection algorithm uses MODIS to detect active fires. Comparing temperature to neighboring pixels determines the severity and extent of the fire. If the difference is over a given threshold, it confirms the “hot spot” as an active wildfire. But if the fire is too small to detect due to the spatial resolution of the sensor, the satellite cannot detect it.

Land Cover

The MODIS instrument tracks land use change by examining its spectral properties over the land. For example, the 500-meter MODIS Land Cover Maps (17 land cover classes) describe the dominant class based on a 10-year span (2001-2010). Additionally, there is a 23-class ESA global land cover product available at 1km resolution.

Cloud Properties

Clouds are fundamentally important in weather and climate. Before MODIS, it was common to believe that clouds covered about 50% of Earth at any given time. But after examining MODIS imagery, it showed that cloud cover was closer to 70%. Also, MODIS accounts for the temperature and height of clouds as well as the composition of ice or water.

READ MORE: 100 Earth Shattering Remote Sensing Applications & Uses

MODIS Imagery and Resolution

Spectral Resolution

MODIS is one of the most versatile sensors with its 36-channel imaging spectrometer. For the first 20 bands, it captures reflected solar radiation. From these bands, we can better understand the physical properties of the environment. For example, we use its 16 thermal bands to measure surface and ocean temperature.

Spatial Resolution

MODIS has a pixel resolution of 250m, 500m to 1 km. Starting with its finest spatial resolution, it can make out features about the size of 3 football fields. But its most important asset is its enormous swath covering a width of 2,330 km at 12-bit radiometric sensitivity.

Temporal Resolution
NASA Worldview

On board NASA’s flagship satellites Terra and Aqua (A-Train), MODIS has a 2-day repeat coverage of the entire planet. Depending on cloud coverage, its temporal frequency makes this sensor a perfect candidate for monitoring any activity on land. MODIS sensors only capture data on the dayside portion because it measures reflected light from the sun. In a polar orbit, the Aqua satellite circles the Earth every 99 minutes.

Reflective Bands

Here is a list of all bands for the MODIS sensor including ground sampling distance and spectral bands.

BandBandwidth (µm)Resolution (m)
10.620-0.670250
20.841-0.876250
30.459-0.479500
40.545-0.565500
51.230-1.250500
61.628-1.652500
72.105-2.155500
80.405-0.4201000
90.438-0.4481000
100.483-0.4931000
110.526-0.5361000
120.546-0.5561000
130.662-0.6721000
140.673-0.6831000
150.743-0.7531000
160.862-0.8771000
170.890-0.9201000
180.931-0.9411000
190.915-0.9651000

Thermal Bands

BandBandwidth (µm)Resolution (m)
203.660-3.8401000
213.929-3.9891000
223.929-3.9891000
234.020-4.0801000
244.433-4.4981000
254.482-4.5491000
261.360-1.3901000
276.538-6.8951000
287.175-7.4751000
298.400-8.7001000
309.580-9.8801000
3110.780-11.2801000
3211.770-12.2701000
3313.185-13.4851000
3413.485-13.7581000
3513.785-14.0851000
3614.085-14.3851000

Conclusion

Today you’ve learned that MODIS is an instrument on board both the Terra and Aqua satellites. Over time, it has become pivotal in improving our understanding of our land, ocean, and atmosphere.

For example, it gives us a peek inside the ocean and broadens our understanding of its biology and food cycle.

In the atmosphere, it helps us get the whole picture of cloud properties and what percent they cover Earth. Lastly, it assists us in monitoring active wildfires, land-use change, and volcanic activity.

Can you think of any other applications on how scientists are using the MODIS instrument? Please let us know with a comment below.

MODIS Bands
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