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UPDATION AND POSITIONAL ACCURACY IMPROVEMENT OF
GEO SPATIAL DATA-INNOVATIONS AT KAMPSAX INDIA PRIVATE LIMITED
S N Mahapatra* *, V K Mahindru? *, A K Swain* *, Alok Upadhyaya? *
* KIL, R&D Division, 813, Phase-V, Udyog Vihar, Gurgaon, Haryana, India - (SNM, AKS)@kampsax.co.in
® KIL, Mapping Division, 809, Phase-V, Udyog Vihar, Gurgaon, Haryana, India-
(VKM,AKU)@kampsax.co.in
PS ICWG IL/IV: Automated Geo-Spatial Data Production and Updating
KEY WORDS: PAI, New mapping, Updation, Transformations, Geometric fidelity
ABSTRACT:
Kampsax India Private Limited (KIL) is engaged in the production of very large mapping projects from all over the world though
mainly from Europe and Latin America with over 35 digital Photogrammetric instruments working round the clock. There is always
endeavour for finding new technical solutions for large volume production with high quality. KIL mainly undertakes
photogrammetric projects involving Aerial Triangulation (AT), Digital Terrain Model (DTM), Orthophoto Production, 3D Vector
Mapping (New Mapping/updation) and 2D Mapping (based on Orthophoto for updation and positional accuracy improvement). Two
of the projects involved the use of old data sets for new mapping/updation and positional accuracy improvement (PAI), where the
old vector data required to be updated and positional accuracy improved using latest Orthophoto. Another project required 3
dimensional new vector mapping with tiff raster files of old maps only as a guide. The accuracy requirement for these projects is of
the order of about 1.25mt in planimetry and height. The projects required establishment of new database while maintaining absolute
accuracy, relative accuracy and geometric fidelity. This paper demonstrates the development of semi-automatic method to improve
the positional accuracy of old vector data maintaining the absolute and relative accuracy as well as geometric fidelity. The PAI
(Positional Accuracy Improvement) apply special transformation to match with the raster image. PAI makes use of special
transformation on old data with a constrained situation in order to achieve perfect matching of vector data with raster image.
Geometric contraction, expansion, dilation, similarity transformations, spiral similarities, rotation and translation all affine
transformations or their combinations are included in this process. The production workflow involves the tiff files of old maps
digitized in 2D, locally transformed and merged with TIN data of automatically generated DTM (Digital Terrain Model) to create
3D vector data. The 3D vector data thus generated is made use for preparing updated new map database. The concept of positional
accuracy improvement is further developed for use in 3 dimensions. These methods have changed the notion that old vector data
cannot be used for new mapping/updation. This potential application makes use of any existing maps digital/paper for subsequent
new mapping and updation.
Mapping, Orthophoto, production using Analogue/Digital Aerial
Images, Satellite Images and Laser Scanned data.
1. INTRODUCTION
1.1 General Introduction
Decision-making demands timely up-to-date information. All
over the world the maintenance of Geo-spatial data
infrastructure is gaining attention and significant proportion of
annual running costs of the organizations responsible is used for
maintaining such data. Whatever the methodology to be adopted
for maintenance for such data, it is always desirable to make use
of the existing data sets. The available data sets may be in the
form of existing digital vector database or the paper maps.
Kampsax India Private Ltd is actively engaged in the production
and maintenance of such geo-spatial databases for different
organizations world over. With 35 Digital Photogrammetric
Workstations in production round the clock, it is one of the
largest photogrammetric production organization offering large
volume production with high quality for Aerial Triangulation,
Digital Terrain Modelling, Digital and Analytical Vector
1.2 Detail Introduction
The paper deals with generation of updated and more accurate
digital vector database starting from the existing data source.
The updation of database can be considered for generation of
2/3 Dimensional vector data. In case of 2D vector data the
updation and positional accuracy improvement may be carried
out using latest orthophoto while for creation of updated 3D
vector data latest stereo aerial photographs are used.
In one of the project handled at Kampsax India (P) Limited, the
existing vector data required positional accuracy improvement
and updation. The fresh aerial photographs are obtained. The
required ground control for carrying out Aerial Triangulation
(AT) is provided as field input. The digital terrain models are
produced for obtaining orthophotos. The orthophotos thus
*
The authors are presently working with Kampsax India Private Limited, Gurgaon, Haryana, India and are engaged in
Photogrammetric Mapping of International Projects at one of the biggest Photogrammetric Production Centre of India. Use
appropriate person in cases with more than one author.
n
