Satellite

Surface Topography Analysis for Feasibility
Assessment Using Satellite Imagery


SMWaypoint’s satellite image analysis specialists located in Phnom Penh.  Some images were acquired from archives and some were acquired by custom order. In the case of the custom orders contained , satellite companies located in the United States positioned their satellites over our client’s specific area of interest.  The images used were both multispectral and panchromatic. A multispectral image is one that captures image data within specific wavelength ranges across the electromagnetic spectrum. Some of the images capture light from frequencies beyond the visible light range, i.e. infrared and ultra-violet.  All are useful in identifying various aspects of the land’s features. The multispectral image contained Red, Green, Blue, Red Edge, Coastal, Yellow, 2NIR and Short-Wave Infrared (SWIR) bands. 

 

 

WE PROVIDING MANY
DIFFERENT TYPES OF SATELLITE IMAGES


ORTHOMOSAIC

This image was captured by satellite with resolution is 30cm per pixel. By using this (in the soft version), you can zoom and see the objects that are equal or higher than 30 cm. Therefore, it can be a valuable aid in project planning.

 
 
CONTOUR LINE

Contour lines are used to determine elevations and are lines on a map that are produced from connecting points of equal elevation (elevation refers to height in meters, above sea level in this map). Contour intervals of both 30m and 10m are provided. When finer resolution is needed the 10m can be used. These can be used in making basic initial decisions on land requiring the least amount of leveling. Areas where the contour lines (isoclines) are close together indicate areas of rapid change in elevation (incline or decline) probably indicating the presence of a hill.

 
 

 
 
Digital Elevation Model Interpretation

DEM gives the overall topography, which depicts the various elevations. With this product, the contours found within the AOI can be easily visualized. This DEM is done in 30m Ground Sampling Distance. A GSD of 30 meters allows you to see objects on the earth’s surface which are => 30 meters.

 
 
 
Flow Direction

Flow direction calculates the direction water will flow using slope from neighboring cells. This is usually determined by the direction of the steepest descent in each cell so that we can understand where water might flow and where water will possibly come from. The arrow points indicate the characteristic of flow direction where water might flow from high into low land area. This map is created using 30-meter resolution.

 
 
 
 
STREAM

These streams could indicate the presence of relatively fresh water which is a valuable resource. However, available water in these streams could be predicated on seasonal rainfall. According to the map below, it appears that the main stream runs through the middle of the area. In addition, there are many small streams, which connect to the main stream as indicated below. Any deforestation in the upper elevations could affect the present water flow.

 
 
 
 
STREAM

These streams could indicate the presence of relatively fresh water which is a valuable resource. However, available water in these streams could be predicated on seasonal rainfall. According to the map below, it appears that the main stream runs through the middle of the area. In addition, there are many small streams, which connect to the main stream as indicated below. Any deforestation in the upper elevations could affect the present water flow.