Survey and Mapping Office (SMO)
Lands Department
The Government of the Hong Kong Special Administrative Region
23/F, North Point Government Offices, 333 Java Road, North Point, Hong Kong
Technical Specifications for Ordering Seamless i-Series Digital Map
Introduction
The mode of ordering i-Series Digital Maps available to users is classified into two types, (1) order
of discrete tile Digital Map and (2) order of seamless Digital Map. For discrete tile Digital Map, the
deliverable is sheet-based according to the user-selected sheet number(s). For seamless Digital
Map, the deliverable is one single file of Digital Map in seamless nature. This paper provides the
list of Digital Maps available for seamless map order and the technical specifications for ordering
seamless i-Series Digital Maps.
Type of Digital Maps supporting Seamless Map Order
In general, all the vector-based Digital Maps support seamless map order. For i-Series Digital Maps
in text file, DGN v8 and DWG v2000 data formats, the seamless map order is supported with
deliverable file size smaller than 300MB. The Digital Maps, with seamless map order available, are
listed in the table below:-
Data Format
Product
Type of Product
FGDB
GML
DGN
DWG
Name
Text File
v9.3.1
v3.1.1
v8
v2000
iB1000
*
*
Digital
iB5000
*
*
Topographic Map
iB10000
*
*
iB20000
*
*
Digital Land
iC1000
*
*
Boundary Map
Geo-reference
iG1000
*
*
Database
* Total file size of each seamless map should not exceed 300MB.
Approaches in ordering Seamless Digital Maps Users may order seamless i-Series Digital Maps by providing either a list of sheet numbers or a
user-defined extent for each product. The following specifications for each approach should be
followed for processing the order by SMO:-
1. Submission of Sheet Number List in Text File Format
The submitted text file should include the product name and sheet
iB1000maporder.txt (Example)
numbers. The text file for seamless map order should be named as
11-SE-11C
“
(ProductName)maporder.txt” with its product name as prefix (e.g. 11-SE-16A
iB1000maporder.txt). Each of the sheet numbers should be kept in
11-SW-15D
(Sheet Numbers)
different lines and to the left edge, as shown in the figure. Each
11-SW-20B
submitted text file is considered as a single request for seamless
map order. The deliverable of seamless i-Series Digital Map shall be in rectangular shape.
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Last updated 2 October 2015
2. Submission of User-defined Extent in Text File Format, Shapefile, DGN or DWG Formats
Apart from the submission of sheet number list, the users can order seamless i-Series Digital Maps
by submitting the user-defined extent in four different data formats. By using this approach, the
users should use
standard frame (e.g. 750m x 600m for iB1000 Digital Map) or
multiple of
standard frame(s) (e.g. 3000m x 600m for iB1000 Digital Map) for defining the required extent.
The deliverable of seamless i-Series Digital Map shall be in rectangular shape. The details and
specifications of the standard frame(s) and data formats are listed below:-
Size of Standard Frames for Seamless Digital Maps
Product Name
iB1000
iC1000
iB5000
iB10000
iB20000
iG1000
Size of Standard Frame
750 x 600
750 x 600
3750 x 3000
7500 x 6000
15000 x 12000
7500 x 6000
(ground distance in meters)
Specifications for defining Standard Frames for Seamless Digital Maps
Data Format
Text File
Shapefile
DGN v8
DWG v2000
(ProductName)maporder
(ProductName)maporder.
(ProductName)maporder
(ProductName)maporder
File Name
.txt
zip^
.dgn
.dwg
File / Layer /
maporder
maporder
maporder
Level Name
Geometry
Polygon
Shape
Closed Polyline
Type
Grid System
HK1980 Grid
HK1980 Grid
HK1980 Grid
HK1980 Grid
i) The Northing and
i) Only the vertices of the
i) Only the vertices of the
i) Only the vertices of the
Easting values of each
outer boundary of the
outer boundary of the
outer boundary of the
vertex should be
user-defined extent
user-defined extent
user-defined extent
delimited by space.
should be inputted into
should be inputted into
should be inputted into
For the same group of
the Shapefile.
the DGN file.
the DWG file.
vertices, each vertex
should be delimited by
space and placed in
the same line of the
text file.
ii) The last Northing and
Easting values of the
vertex of the standard
Remarks
frame should be the
same as its starting
vertex indicating that
the submitted
standard frame is a
closed geometry.
iii) Only the vertices of
the
outer boundary of
the user-defined
extent should be
inputted into the text
file.
^The mandatory files of shapefile, i.e. shape (.shp), shape index (.shx) and attribute (.dbf) formats, should be put in a zipped file.
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The Digital Maps’ users can refer to the following template and examples for realizing the
specifications for the submission of user-defined extent.
Template and Example of .txt File
Template
Example
(ProductName)maporder.txt
iB5000maporder.txt
E1 N1 E2 N2 E3 N3 E4 N4 E1 N1
(1st User-defined Extent)
834038 816465 837788 816465 837788 813465 834038 813465 834038 816465
Reference User-defined Extent using standard frames
Example
1
2
Coverage of User Extents
4 Nos. of iB1000 standard
4 Nos. of iG1000 standard
frames
frames
Images
(2 x 7500 m)
(4 x 750 m)
15000 m
(Ground Distance in meters)
3000 m
600 m
(2 x 6000 m)
12000 m
Enquiries on the Purchase of Digital Maps For any enquiry on the purchase of Digital Maps, please contact us through the following
channels:-
Address:
Map Publications Centre, Hong Kong
Survey and Mapping Office, Lands Department, 23/F North Point Government Offices
333 Java Road, North Point, Hong Kong
Telephone:
(852) 2231 3187
Fax:
(852) 2116 0774
Email:
[email protected]
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Last updated 2 October 2015
