Draft operational guidelines of digital india land records modernization programme (dilrmp) introduction

Mouza Code	Sheet no.	L or R for LR / RS	First plot no.
Last plot no.
1	2	3	4	5

Table no. 4 - This table will keep track of missing plots and missing plot numbers within the 1^st and last plot numbers in a particular sheet of a mouza.

Mouza Code	Sheet no.	L or R for LR / RS	Missing plots.
1	2	3	4

5. Stringent accuracy requirement:
The digitized map should exactly match the original map, like a contact print, since the dimensions and area of plots, or the whole village, are to be extracted from the map itself. As such, a difference of 0.25 mm of sheet measurement in 1:3960 scale between the original map and its copy, whether conventional or digitized, gives rise to a difference of about 1 metre on the ground. So, an accuracy of 0.25 mm or higher is desirable and tolerance may be treated as nil to 0.25 mm per metre.
6. Outputs of digitization:
6.1 Vectorised map can be stored in any open GIS format without any loss of freedom, as the conversion from one format to another is built into the software for raster to vector conversion. One of the popular open formats is SHP format, which is essentially a bundle of three formats to store spatial objects in .shp, text data attached to spatial objects in .dbf, and the format for linkage of .dbf and .shp, i.e., .shx. Many popular raster to vector digitization software are available, which can be used, such as R2V or AutoCAD map. These GIS files are to be provided by the digitizing agency/vendor to the Revenue Department in CD media along with a printout of the digitized map.

6.2 About 35 files are generated for a typical GIS-ready mouza map, namely:

Serial No.	File Name	Description
1.	JlNo.shp	Shape file for Mouza Map Sheet
2.	JlNo.shx	Shx file for Mouza Map Sheet
3.	JlNo.dbf	Dbf file for Mouza Map Sheet
4.	Alml. shp	Shape for Alamat in line layer
5.	Alml. shx	Shx file for Alamat in line layer
6.	Alml.dbf	Dbf file for Alamat in line layer
7.	Almp.shp	Shape file for Alamat in Point layer
8.	Almp.shx	Shx file for Alamat in Point layer
9.	Almp.dbf	Dbf file for Alamat in Point layer
10.	Bnd.shp	Shape file for Sheet Boundary, it denotes the extent of the sheet.
11.	Bnd.shx	Shx file for Sheet Boundary
12.	Bnd.dbf	Dbf file for Sheet Boundary
13.	Centroid.shp	Shape file for the points where to place the Plot Numbers
14.	Centroid.shx	Shx file for the points where to place the Plot Numbers
15.	Centroid.dbf	Dbf file for the points where to place the Plot Numbers
16.	Img.shp	Shape file for the points where to insert the GIF files
17.	Img.shx	Shx file for the points where to insert the GIF files
18.	Img.dbf	Dbf file for the points where to insert the GIF files
19.	Mbnd.shp	Shape file for Mouza Boundary
20.	Mbnd.shx	Shx file for Mouza Boundary
21.	Mbnd.dbf	Dbf file for Mouza Boundary
22.	Scale.shp	Shape file for Scale of the Mouza Sheet
23.	Scale.shx	Shx file for Scale of the Mouza Sheet
24.	Scale.dbf	Dbf file for Scale of the Mouza Sheet
25.	Text.shp	Shape file for Texts of the Mouza Sheet
26.	Text.shx	Shx file for Texts of the Mouza Sheet
27.	Text.dbf	Dbf file for Texts of the Mouza Sheet
28.	sign.gif	Gif file for Certificate book
29.	alm_bata.dbf	Dbf file for conventional signs or alamats along with the reference of bata plot no.
30.	missp.dbf	Dbf file for Missing Plots in Mouza Sheet
31.	first_last.dbf	Dbf file for First & Last Plot Number for Mouza Sheet
32.	lege.gif	Gif file for legends
33.	name.gif	Gif file for Map Heading, i.e. it contains the District name, Mouza name, Idn etc.
34.	bata.gif	Gif file for list of bata
35.	Idn.tif	TIF image file for Mouza Map Sheet (raster image)

Sometimes, the legend is broken into more than one file. These files are named lege1.gif, lege2.gif, lege3.gif and lege4.gif. Accordingly, the total number of files varies from 35 to 38.

7. Methodology for digitization:
7.1 The Directorate of Land Records and Survey is the nodal organization under the Govt. of West Bengal. Currently, the organization is involved in digitization of mouza maps from existing manually-prepared maps. The process involves (i) scanning of maps to produce raster data, (ii) checking the dimensional accuracy of the raster data, (iii) garbage cleaning in the raster data, (iv) vectorising the raster data, (v) cleaning the vector data, (vi) topology building, i.e., building each plot polygon as a totally connected entity, to ensure that all the polygons are closed and connected; (vii) data integration, (viii) map composition from different layers, and (ix) integration of regional language script as label.