| Sl.no.
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| High Resolution Satellite Images
| Aerial photos
| Ground Survey (Total 100%)
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| 1.
| Preparatory work for Mapping
| Provision of Extents of the area for Satellite image to the agency (specifications – broad level needed)
| Provision of Extents of the area, to the agency, and finalisation of the frames required (area), (detailed specifications needed)
| Start from the scratch, extensive planning of the work, coordination with teams (whole to part method), need for proper base map
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| 2.
| Procurement and clearance ·
| Procurement from NRSA
no clearance required (restricted areas will be masked) ·
| Flying / Photography from NRSA
·
Defence clearance required
| From any registered surveying agency (survey work)
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| 3.
| Availability of data
| Available throughout the year
| Seasonal (Dec-April)
| Ground Survey work can be done any time (except summer season)
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| 4.
| Approval of competent authority
| NIL
| Ministry of Defence Approval takes minimum 3-4 months
| NIL
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| 5.
| Cost of data
| Quick bird – (35 $ per sqkm) Rs.1750/sqkm
| Photography, (flying) scanning, mosaicing – Rs. 6750 sq.km
| At the completion of the project – will get estimate.
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| 6.
| Establishment of Ground Control points
| Less GCPs required, 1-5 Nos. for every 10 sq.km. (50 primary (principal) control points, tie points, well distributed for inter- visibility and for Ground Survey
| Comparatively more GCPs required (min 4 per bundle)
| Depends on the area covered. (more numbers even at every street/road)
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| 7.
| Prepointing
| 5 to 10% of total control points, act as for prepointing
| Cost – 7000 Rs. Per Point ( Rs. 3,000 for monumentation and 4,000 Rs. For GPS observation)
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| 8.
| Rectification of Data
| Rectification of Satellite Images using GCPs, Rs. 1,750 / sq.km
| Part of Photogrammetry - Data capture process
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| 9.
| Data Capture
| For Feature extraction, Rs. 12,800 / sq.km
| For Photogrammetry / Data Capture Rs. 25,600 /sq.km
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|
| 10.
| Ground Survey / Field Verification ·
| Ground Survey work is needed, for property & utility details. (Property boundaries, building details and other utility details·
The details other than in from base map are needed ·
| Ground survey work is needed for property & utility details. ·
The details other than from the base map only needed
| 100% Ground Survey work, all the details – included details required for the base map apart from the property & utility details, property boundaries, building details & other utilities like drainage, electricity, water supply etc.
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| 11.
| Total Cost / Sq.km for Ground Survey Work
| Rs. 23,300 for Data Cost & data extraction, part Ground Survey Work Costs– 20,000 to 30,000 per sq.km depends on the amount of details needed for the project
| Rs. 39,300 for data & data extraction, partground Survey works 20 to 30,000 per sq.km, depends on the amount of details needed for the project.
| Total cost is (min) Rs. 80,000 to Rs.1,00,000 / sq.km, it will vary for high medium and low densely built up areas.
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| 12.
| Time
| Maximum 2 or 3 months for acquisition of data, data capture works and part Ground Survey Work, one or 2 months
| Maximum 2 or 3 months for acquisition of data (subjected to MOD Clearance ) and part Ground Survey works for one or 2 months
| Time required is minimum 3 to 5 months for one sq.km area, it will vary depends on the density of the area
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| 13.
| Area Coverage
| More area covered in a single scene (16.5 x 16.5 km )
| Less area covered per photo
| Less area covered (in order to maintain accuracy)
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| 14.
| Contour intervals
| 3 m Contour
| 1 m Contour
| Flat Terrain – 0.2 to 0.5 m
Hilly Terrain – 1.0 to 2.0 m
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| 15.
| Updation
| Repetitive coverage, available throughout the year
| Availability is based on request for flying (fresh data)
| Tedius to carry on updation, resurvey work and cost also increases by two fold.
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| 16.
| GIS Database development ·
| GIS ready format (Arc images coverages / shape files)·
No time required for GIS database development ·
| Data cleaning is required·
Topology building is to be done·
Bringing it to GIS compabile format·
30% total project of time required for this work ·
| Survey data has to be converted into drawings then clean up & topology, then GIS database to be developed·
50% of project time required for Database Development
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| 17
| Availability Control : Eror and verification ·
| Not much , except the system generated·
Cross verification is easier with the satellite image ·
| Error accumulated from the photogrammetryprocess and database.·
Cross verifications is possible with the help of photos ·
| Susceptible to lot of errors ( human involvement)Ground Survey, conversion of survey data & database developement·
100% cross verification is tedious and not able to verify all the areas.
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