MAP TRANSFORMATION METHOD FROM ANALOG TO DIGITAL FORMAT

1 Beniamin MIRZA, 2 Ciprian Florin ISPAS, 3 Ionut Constantin BARBULESCU

University of Agronomic Sciences and Veterinary Medicine of Bucharest, 59 Mărăşti

Telefon: +40 (21) 318 22 66, Fax: +40 (21) 318 28 88, Email: post@info.usamv.ro

Corresponding authors email:i_like_surf@yahoo.com,cc.ispas@yahoo.com,barbulescu.c.ionut@gmail.com, prof.

Coordinator:radu.mudura@gmail.com

Abstract

This article is aimed to present a map transformation from analog format into digital format, with ArcGis 10.1 software , the latest version..To reach digital format, certain steps must be completed that are mentioned in the paper. All topo-geodezic works are executated in the Stereographic Projection 1970 wich is used in our country today.The proces begins by scanning map using a high precision scanner.After that, the map is inserted into the ArcGis 10.1 program,is georeferenced and finaly we digitize it using elements such as: point (fountains, elevation terrain etc), lines (roads, electrical network, rivers etc) or polyline (villages, forrests, orchards etc).

Key words: analog, digital, stereographic, transformation.

INTRODUCTION

The easiest way to work with a map is digital mode, but for this,the map should be transformed from analog format to digital format

through the process of scanning and georeferencing.The map in digital format has a greater applicability,because you can work with it in different software and different tools

for high precision.With the new version of ArcGis and more exactly ArcGis10.1,we made a complete and high quality georeference.

MATERIALS AND METHODS

To transform the map in digital format we had to scan the map with Canon scanner from GIS laboratory with a 300 dpi (dots per inch) precision. The result was a JPG imagine wich we entered in ArcGis software 10.1 where we georeferenced and digitizated the map.

RESULTS AND DISCUSSIONS

Transformation of a map from analog to digital format begins with scanning process. For scanning, we used a 1:25000 scale map as it is observed in this imagine:

For the beginning we have to transform the corners of the trapeze from geographic coordinate in Stereographic Projection 1970.We can use several conversion software: TransDatRo, TopoSys, Geotools, PlanServMDI, Total Transform,Nego . These software are able to transform corners of the trapeze from geografic coordinate to stereographic coordinate, or points and points files.For example with Nego software it is possible to introduce the trapeze nomenclature and rezults the corners of the trapeze in stereographic 1970 coordinate.

We introduce the map nomenclature and select „Calcuate” to obtain the corners coordinates in Stereographic 1970 Sistem.

We save the resultated coordinates to use them in georeferencing process.

For georeferencing we follow this steps:

1) We launch ArcMap 10.1,select ,,Blank Map” and press OK.

2) We bring the map like this:1)Add Data

2)Select map 3) Add4)Rezult our map.

3) We save the project: 1)File 2)Save As Save in: C:/ArcGis 3)File name:Gis4) Save

4) Now we go to: 1)View 2)Data Frame Properties/General/ 3) Units la Map si Display and select 4)Meters. 5)Apply 6) OK . For control we visualize the bottom right corner of ArcMap window where it must appear meters.

5) If Georeferencing is not in the main bar we go to:1)Customize 2)Toolbar s3)Georeferencing, then we drag it into the menu bar.

6) We zoom trapezez corner where we want to introduce coordinates by using the Zoom application from the main menu bar.

7) We zoom in to the corner we want to introduce the coordinate using the button from the main bar.Now we select: Georeferencing Add

Control Points and go to the first corner we want to georeferentiate.We zoom in with” +” button from menu bar,then click with the right mouse button when we are located at the intersection of the trapeze’s corner. (the trapeze corner is given by the geographic coordinate intersection)and without moving the mouse we press left click,and then right click on Input X and Y, then passing to the coordinate introduction (remember that they are reversed).We do the same thing with the other 3 corners in clockwise 1,2,3,4.

We introduce now one by one the coordinate X and Y

of the trapeze corners. This is the result of georeferencing.

9)Now we press Full extend from the menu bar or right click on Table Of Contents/Layers /L-34-107- D-c ( the trapeze nomenclature),to get the full view of the trapeze.

10) In order to check if georeferencing was done correctly,we press left click View Link Table and examine pairs X and Y coordinates of the four corners of the trapeze. We check if we entered correctly the 4 pairs of coordonate in the corners;if not we select the mistake and press Delete

11) For saving georeferencing we follow this steps GeoreferencingRectify, choose a name and Output Location :we choose the place where we want to save, and then click Save.

12) Now we go to the directory where we saved our geo-referenced trapeze and we bring it with Add Data command

13) Now we need initial trapeze us Trap25miii.JPG name and we position the mouse on its name in the Layers palette and then press the right click and select Remove.

14) Our georeferenciated trapezoid it is a little bet rotated and is a file with extension .tif. We can recognize that is correctly georeferenciated by reading every trapeze corner and confronting coordinates of

the four corners of the trapezoid in Stereo 1970. After that go to menu bar and press Save to end the georeferencing project.

B) We create shapefiles following this steps:

1) From menu bar we select with left click mouse Windowsn application and select catalog option ,wich we introduce it in the right part of our window.Then we press right clik on HomeNewShapefile.

After selecting Shapefile we create themes used to digitize map.The first theme that we want to create is called Localitati.-Name: we write Localitati, the we choose Feature Type Polygon. Before pressing OK we click Edit and select Project Coordinate SystemNational GridEuropeStereo 1970 OK and then click OK to Create New Shapefile.

This theme created is in the left side in Table of Contents with the name we gave it. We press right click of the mouse on LocalitatiOpen Attribute TableTable Options Add Field on Name we write name, on Type we select Text after that we press OK and the same to the next ones until we introduce all the fields we need.

After all filed are created,Attribute Table looks in this way:

This is the process of creating all the shapefiles.For this shapefiles are choosen Future Types such as: polygon, poliline and point.Exemple of shapfile and Future Types used:-rivers ( polilines )-lakes ( poligon)-orchards ( poligon )-leveling ( polyline )-roads (polyline )-shares ( point )-forrests ( poligon)In the following images we will present digitization of one village from our map wich finaly we should to digitize all of it to be called map in digital format.

1)

2)

This is the digitization process.

3)

In this way is transformed a map from analog to digital format.

Bibliography:Lucrari practice-Doru Mihai 2013