The survey

The first phase of each project involves the surveying. It 's the process that describes the size and geometry of the network (in addition to determining the slopes of the pipelines) and, absolutely, is the longest and delicate.


The longest because it can last from a few days to several months (In figure, a survey obtained after 3 months of work) depending on the size of the land and the required precision.

Once you have made the survey it will contain the planimetric information (such as shape and size of the sector) and altitude (the altitude at each point detected). Knowing the elevations you can calculate the slopes of the pipeline: at present no instrument except IrriPro, manages to consider the slopes for each part of pipe and the elevations of each emitter. The only information used by third-party software is slope value, which is considered constant for the entire length of the pipeline: this produces gross miscalculation and incorrect project. IrriPro, by contrast, allows you to take into account in hydraulic calculation all planimetric and elevation data that describe the terrain: each part of pipe will present the right slope, and each emitter will be placed at the correct altitude. Furthermore, in order to make it easier and fast as possible the acquisition of 3D terrain model, the software offers three different ways to enter data:

 

Extracting 3D model of the land through the service of Google MapsProcessing contour lines and known elevation point in scaleImporting CAD files with recognition of the contours and shape of the field
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The surveying service of Google Earth/Maps, included in IrriPro software, is also available on-line at this link.

Further on, are described in more detail, the technology and the method behind the survey through Google Maps.


 

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.

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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.
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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.
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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:

 

GOOGLE MAPS GIS DATA AVAIBILITY

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