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

2. Field Measurement Book (FMB)
FMB is a sketch showing measurement boundaries of the survey number. It is a rough sketch and not to scale. It provides a record of measurement and boundaries. Field Measurement Book contains several field measurement sheets covering measurements of all lands in a village. In some cases it is drawn to a scale of 1:1000 or 1:2000 showing all field and subdivision boundaries and their measurements. It is also called the atlas of field maps. A record of measurement of individual fields and subdivisions is thus provided, which will enable any inspecting officer to identify the boundaries, and whatever is required for investigation of boundary disputes, detection of encroachments, and for the measurement of further sub-divisions, etc.

2.1 Various components of the Field Measurement Book are discussed below:
2.1.1 G-line
This is an imaginary line (Guess Line) which converts the map into various sizes of triangles in order to accurately fix the boundary lines and the various points in the map. This line is the foundation on which the entire map is built. Any error in a G-line will affect all calculations based on that G-line.

2.1.2 F-line
It is the outer boundary line in a sketch, which signifies the actual field boundaries of the outer lines of the sketch. The F-line points are fixed with reference to its offset distance from the G-line.

2.1.3 Subdivision lines
These lines demarcate a small parcel of land within a survey number. A sub-divisional polygon’s extent is directly correlated to the extent found for the particular sub division. The sub-division lines are generally defined through a ladder, except for the graphical representation in the FMB.

2.1.4 Ladder
As mentioned earlier, the field line points are defined with reference to an offset distance from the G-line. The offset distance may be to the left or right side of the G-line. This left or right angle deviation (offset) is depicted by the ladder. By converting the ladder details into electronic data, once can produce the outline of the FMB sketch. The ladder details get attracted whenever there is a change in the field line, involving a bend.

2.1.5 Extension lines
Each survey number field is an integral part of the village map and hence other fields surround each sketch. The exact direction in which the subject field joins the neighboring field is shown on the FMB as an extension line.

2.1.6 Neighboring field survey numbers
As mentioned earlier, each survey sketch is surrounded by other fields. These surrounding field numbers are marked around each FMB. This enables mosaicing of FMBs into D-sketches and village maps and so on.

3. In FMB, the traverse coordinates are provided in five columns. The FMBs also depict the dimensions of each field boundaries and the sub-divisions. As mentioned earlier, the field line points are defined with reference to an offset distance from the G-line. The offset distance may be to the left or right side of the G-line. This left or right angle deviation (offset) is depicted by Ladder. By converting the ladder details into electronic data, once can produce the outline of the FMB sketch. The ladder details get attracted whenever there is a change in the field line, involving a bent.
4. At present, Field Measurement Books are drawn and maintained manually. Digitisation of Field Measurement Books will result in faster processing of the FMB sketches including creation of new sub-divisions, modification of existing sketches, portability of data, facility to draw the FMB sketches to different scales leading to higher clarity, and quicker delivery of copies of FMBs to land-owners.