Why do we use remote sensing images to study earth? what do infrared pictures show us that visible light don't

Answer 1

Remote sensing satellites such as LANDSAT use different frequency bands for land use analysis.

The amount of each frequency that is absorbed is different for each material. For instance an Infrared picture of vegetation would show stark differences between Marajuana plants and the surrounding foliage. This might be useful.

Remote sensing gives us the ability to examine the Plant types and soil types of an area without visiting it. It's not foolproof so a process called "ground truthing" needs to be performed, you have to a visit a similar area and examine the materials that are present. The results of the ground truthing process are extremely valuable in the calibration of local images.

Gross structures can also be defined but resolution is relatively low, in the order of metres. Dome like deformities in rock strata indicate that hydrocarbons could be present in the subsurface. The next step would be to perform close in Geophysical surveys from an airbourne platform, LANDSAT type imaging at a high resolution, Gravity surveys and Magnetic surveys can be performed from a plane. This is also remote sensing.

The main contrast on Infrared images is Vegetation.

Answer 2

Light bulbs? Actually, very little infrared or visible light reaches the earth at night. However, the earth is warm, and radiates infrared at all times. At night the outgoing infrared energy is greater than the incoming infrared energy. On the average, the earth is close to balance on its energy in/out budget. Perhaps a small bit more is coming in than out, given evidence that the world is warming. We do not yet understand this effect well. There are those who tell us it is because of the effects of man's activities. Note that it appears that Mars is also warming (its polar icecaps seem smaller than they used to be). I doubt this is from human activity yet. We should, whether we directly contribute to global warming or not, be good stewards of our environment and should minimize waste of all kinds (energy especially) because we do live on a planet with only limited resources.

Answer 3

Clouds

Answer 4

Certain structures are best seen from space, while infra red is used mainly to determine temperature variations among other things.

Answer 5

You can see some structures that are under the ground (like roman roads), you can see temperature differences that could mean many different things.

Answer 6

I can't see through clouds, can you?

Answer 7

hotspots

Answer 8

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