SVG MAP Lab

Base map of japan with 1:25000 resolution

This page is English Version of the Japanese article of this blog.

We open a base map of Japan that uses Digital Map 25000(Spatial Data Framework).
This map is tiled maps divided equally based on "Grid Square of Third Area Partition". The tiling is achieved by the hierarchical SVG Map container data with three hierarchies.

Amount of files: About 350,000 tiles
Total data size: About 1.2GB (They are totally static data.)

Please access following URL by using PC in which SVG Map Toolkit is installed.
URL: http://www.svg-map.org/svg/basemaps/worldNm25k.svg

The high-resolution map will be displayed if expanded to some degree.
#Note: A part of data of Ishikawa Prefecture is missing.

Base map with auxiliary-line of Secondary Area Partition is also opened.
URL: http://www.svg-map.org/svg/basemaps/worldNm25kmesh2.svg

「この地図の作成に当たっては、国土地理院長の承認を得て、同院発行の数値地図25000(空間データ基盤)を使用したものである。(承認番号 平成15総使、第229号)」

数値地図25000ベースのSVGベースマップ

数値地図25000(空間データ基盤)を使ったSVG Map形式の日本の基盤地図を公開します。
3次メッシュ単位に等分割した地図を3段階の階層的なコンテナによりタイリングしています。

総ファイル数　約35万個、合計ファイルサイズ　約1.2GB、完全に静的なデータです。

ＵＲＬ：http://www.svg-map.org/svg/basemaps/worldNm25k.svg

SVG Map ToolkitがインストールされたPCでお試しください。ある程度拡大すると、数値地図25000レベルの地図が表示されます。
＃注：石川県の一部にデータ欠落があります。

2次メッシュの補助線入りの地図も公開します。
ＵＲＬ：http://www.svg-map.org/svg/basemaps/worldNm25kmesh2.svg

「この地図の作成に当たっては、国土地理院長の承認を得て、同院発行の数値地図25000(空間データ基盤)を使用したものである。(承認番号 平成15総使、第229号)」

The system which performs hyper-layering of a landslide map and a 1:25000 topographical map

This page is English Version of the Japanese article of this blog.

We release the SVG Map based web map mashupping system which performs a composite view (Hyper-Layering) of landslide map data base which National Research Institute for Earth Science and Disaster Prevention releases and 1:25000"DENSHI-KOKUDO" topographical SVG map which released Geographical Survey Institute.

Please access the following URL with PC in which SVG Map Toolkit was installed.
http://www.svg-map.org/svg/wmsGw/CJ_BOSAI.svg

Supplement :
In this system, the SVG-ize server which enables it to treat the map services provided by the WMS specifications of OGC as SVG Map is used.
# The server of an original landslide map has a WMS interface.

The SVG-ize server is only a server which generates the container SVG data which refers to a WMS server instead of a gateway which performs the reworking of the data of a WMS server. Therefore, the processing is light and constructing as a static data is also easy.  (See Also: Relationship between WMS and SVG Map )

Although some characteristic mechanisms are further included in this server, I would like to explain in full detail separately about those mechanisms.

Rendering performance of SVG Map

This page is English Version of the Japanese article of this blog.

We achieved the rendering performance comparison of the mapping platform following the article on the storage efficiency. The data used for it are as follows.

1. The coastlines in Japan which makes the GLOBAL MAP an origin
   SVG:0.9MB, GeoJSON: 1.6MB, KML: 2.3MB
2. The roads in Japan which makes the GLOBAL MAP an origin
   SVG: 10MB, KML: 29MB
3. The river lines in Australia which makes the GLOBAL MAP an origin
   SVG: 54MB

Among these, the data of 1 and 2 is the one having used it in the article before.

The environments used are as follows.

SMT	SVG Map Toolkit 0.6
FFX	FireFox3.0.1
OPR	Opera9.5
ASV	Adobe SVG Viewer 3.0
REN	Renesis Player 1.0
OLI	OpenLayers 2.6 / Internet Explorer6
OLO	OpenLayers 2.6 / Opera9.5
OLF	OpenLayers 2.6 / FireFox3.0.1
GMI	Google Maps / Internet Explorer6
GEO	Google Earth 4.3

Everythings are operated on Pentium M 1.1GHz 768MB WindowsXP(JP).

Performance measurement results concerning data "1" (unt:[seconds])

SVG					GeoJSON			KML
SMT	FFX	OPR	ASV	REN	OLI	OLO	OLF	OLI	GMI	GEO
0.6	1.5	1.2	1.7	0.7	Hang up	9	11	Hang up	Stall	2.5

Performance measurement results concerning data "2"
(OpenLayers and GoogleMaps dropped out. )

SVG					KML
SMT	FFX	OPR	ASV	REN	GEO
2	19	11	17	6	43

Performance measurement results concerning data "3"
(KML dropped out. )

SVG
SMT	FFX	OPR	ASV	REN
11	51	34	48	17

Processing speed of SVG Map Toolkit was the highest among these. It is because it is tuned by paying attention to the rendering performance of map data.

On the other hand, though this was expected, viewers coded with javascript (OpenLayers and Google Maps) seems to be far behind native code viewers, in the point of the performance. It seems that a lot of various resources were consumed, and operation was also unstable.

The display of the vector data may be very important for the map services. And, we are considering that drawing of the vector data at "1" level should be able to be executed easily. (If it is a compressed format (.svgz), such data is a suitable size for today's WWW.) However, it might be considerably difficult for today's ordinary PC as long as it depends on javascript viewers.