Satellite Image Interpretation

                                                   

Introduction:

Satellite Images are similar to that maps, these are essential and provide various range of information. Through Satellite Images changes on the earth is monitored like transformation of city, Land-use and Land cover region, Monitoring of crop health & growth and climate condition. To reveal the rich information in a satellite Image following steps are needed.   

1.      Identifying Scale of Image

2.      Identifying the pattern, shapes and textures

3.      Identifying the color

Identifying Scale of Image

People have trend to look at Satellite Imagery for identifying region or area which are familiar to them, these can be house, work place, nature feature. Identifying house or fine details in satellite image is possible, but the information are gather by commercial and military satellites which are costly to acquire or banned for public uses. The acquired information from the image are finer, capturing the houses and cars on the roads, but covers a lesser area.

Depending on the Image resolution, a full city can be captured in single image, an image can cover 1km or 100km based on the resolution. Each Scale have its own uses, for example analyzing flood requires high resolution imagery for identifying the affected areas, identifying flood prone region and tracking the accumulation excess water.    

Identifying the pattern, shapes and textures

Interpreting satellite imagery is better by understanding pattern or shapes on it, because distinctive pattern can be easily matched to external map for identifying important features. Waterbodies, River, Ocean are simplest feature for identify because of distinctive shape.

Pattern on the maps are derived based on Land-use, for example the farms land have geometric shapes like rectangle, circle which are not seen naturally. Square shapes are identified in forest region, Straight line are easily related to human activity like road, canal. 

Identifying the color

The various structures and land can be identified in the picture using its color scale in the map.

The Level I classification includes:

- Settlements – Light Blue based location

- Road – Black

- Forest – Dark Green

- Vegetation – Green 

- Waterbodies – Blue & Dark Blue

- Wasteland – Pink