THE SURVEY BY GOOGLE MAPS/EARTH

Thanks also to the revolutionary technology for survey from the Google Maps/Earth on-line service, available within the program, you can perform the topographic survey of the area where you implement the system without moving from your PC: You will get 3D model of the land: this feature is used to perform the topographic plano-altimetric survey of the area where will be designed and built the irrigation system.

	Through this console you can make a topographical survey of land simply by identifying the area to be detected . The user can use this feature to: Surf in 2D or 3D, as in Google Maps by entering coordinates or name of the place. Develop the satellite imagery identified by choosing the precision level of survey from 25 to 2500 points collected from a processing time of up to ten minutes.
	IrriPro matter the satellite imagery and GIS data (DEM as ASC file) to calculate coordinates and dimensions of each object that will be included in the workspace of the software. The DEM (Digital Elevation Model) product is a raster data model, in the case of 2500 detected points, it consists of a matrix square mesh of 50 rows and 50 columns. The characteristics listed in the plano-altimetric DEM are georeferenced to the UTM-WGS84.
Knowing the plano-altimetric trend of the land, slopes and elevations will be allocated to the elements (such as pipelines and regulators) according to their position. Throughout the work area, the elevations (listed next to the mouse cursor) were obtained through a SPLINES-type interpolation procedure of DEM data. Intercepting points of equal altitude with lines you get the various contour lines.

RELIABILITY OF THE GIS DATA IN GOOGLE MAPS/EARTH

From studies carried out by the company Irriworks, it appears that the quality of data extracted from GIS service Google Maps is comparable to the same level of a technical mapping on a scale of 1:10,000 and then sufficiently reliable for the design of irrigation systems. In addition, you should not underestimate the great difference of time, resources and equipment to be used for the construction of a detailed survey: For the areas under study, this has required a time of 3 months compared to the few minutes used to extract data through the GE service, whereby it is possible in real time and in the areas where you do not have a traditional cartographic support, to obtain a reliable representation of the difference plot.
Following3documentsofdifferent sourceson the precisionandaccuracy of theplanimetricandelevation datareturned from the serviceGoogleEarth / Maps:

• AN ASSESSMENT OF DIGITAL ELEVATION MODELS (DEMs) FROM DIFFERENT SPATIAL DATA SOURCES (Nigeria).pdf
• L’accuratezza dei dati di Google Earth (Pavia).pdf
• Affidabilità dati GIS DA Google Earth(Sicilia).pdf

GOOGLE MAPS GIS DATA AVAIBILITY

Map data are available all over the world but some areas. Click here to check the coverage table.