These accuracy standards can be con-
veniently achieved by employing numerical
methods of stereophotogrammetry. Even
precision analog instruments, coupled with auto-
matic data recording device can be used. How-
ever, work-stations with PC- based digital systems,
which are capable of processing numerical data,
extracted from sterco models, will be a better
configuration as this could dispense with manual
drills of absolute orientation, thereby eliminating
residual errors on account of sources like projec-
tion and plotting of control points, scaling error
due to bias or personal judgement. The
photogrammetric data could be captured either
from a relatively-oriented model or from an
analytically-absolutely oriented model. In the
former case, the model co-ordinates could be
transformed to terrain terms using sophisticated
software, and inthe latter case, after achieving
numerical absolute orientation, the model points
also could be got transformed to terrain terms
using the transformation parameters. From these
ground co- ordinates of all corners and turning
points ol the holdings, a blue-print for the village
map could be prepared through computer design
files, which could conveniently be used for ground
verification, in case the photographic products are
not preferred. From the ground verified informa-
tion, the extraneous bunds, not forming boundary
limits of any holdings, could be eliminated and the
data in the computer could be edited and updated.
Using the above and various attributes collected,
the individual plot map could be plotted giving all
desired dimensions, area of the plot and land-use
data, a specimen copy of which has been given as
Appendix II. By consolidating all these plot maps
pertaining to one village, a village map and com-
bining the constituent villages, a mandal map, on
a convenient smaller scale, can be produced as
computer outputs. The advantages of this modern
technique will be that the data could be stored in
digital form on floppies, facilitating easy peri-
odical updating by the Cadastral Survey Organiza-
tion, after acquiring necessary technical
know-how through interaction with the survey
department. This technique can supply the end-
products in the form of soft and hard copies of
computer output. Other advantages are storage-
convenience, easy retrieval, editing facilities, and
scope for supplementing it with multi-cadastre
data for other user-organizations, as and when
required.
318
GOA CADASTRAL SURVEYS
This project was undertaken during 1971
covering an area of 8,000 hectares consisting of 16
villages. The aerial photography was taken in
January, 1970 with RC 5a camera, 11.5 cm focal
length on 1:6,700 scale approximately. Enlarge-
ments on the scale of 1:3,000 were also used.
Before the aerial photography, demarcation and
pre-marking was carried out. In view of the prac-
tical problems involved in pre-marking every
property holding, it was decided to do the pre-
marking only for survey number boundaries i.e., a
group of holdings. Most of these boundaries fol-
lowed field bunds making identification easy. The
pattern of pre-marking consisting the trenches in
the shape of a cross, the legs being 50 cms x 15 cms
with a gap of 75 cms square in the middle. Sub-
sequently, model control was provided using
electronic distance measuring (EDM ) instru-
ments for planimetric points and spirit-levelling
for heights. Pre- marked points, clearly identifi-
able on the photography, were included as control
points. Photogrammetric processing was carried
out on the basis of photographs verified on the
ground for fixing of individual land holdings. Plot-
ting was done on wild A7 and A8 stereo plotters.
Co-ordinates were read for all the pre-marked
points, besides some other sharp points. This
material was used for field completion. Plotting
was carried out village-wise on 1:1,000 scale. Vil-
lage maps on 1:5,000 scale were also produced.
Record of Rights (ROR) was also generated. Out
of 8,000 hectares of the area attempted 4,000 hec-
tares consisted of built-up and covered areas in-
volving extensive ground work. The cost per
hectare by photogrammetric method worked out
to Rs.64/- as against Rs.72/- by conventional
method. Though this project was a technological
success, the introduction of modern methods suf-
fered set back due to other factors.
ANGUL-NALCO CADASTRAL SURVEY
PROJECT IN THE STATE OF ORISSA
This is a collaborative project between Sur-
vey of India and Department of Land Records and
Surveys, Govt. of Orissa, funded by Ministry of
Rural Development, Government of India. The
objective is to survey 400 villages. Aerial
photographs on 1:10,000 scale have been used.
Ground control has been provided using EDM
instrum
results
compa
ments
approa
stereo
and otl
admini
speed
to cost
GPS F
provid
signals
techno
also. |
replace
using |
Were m
ferenti
observ
the tr:
CGITOFPb-V
well in!
buildir
and sp
ards. |
nology
and 11
very
using t
CONC
ning aj
lated t
where
ture ar
tively.
dimen:
on gen
digital
ves hu;
and ti
Got. |