Explore the Web map from a quiz

Topic cut

A bit of time in the afternoon, in the knowledge of the topic of GIS, in the essence of the question and Answer section found an article titled "Google Maps originally did not use vector map rendering, but download rasterized image and then render." "Article, by looking at replies to know about the 2012 article. Although it has been a few years, this problem is still very classic in the Web map field. But probably not the GIS industry people do not understand what the title means, simply say: In fact, the title should be "Google Basemap" rather than "Google Maps", the map includes a basemap and other layers and symbol tags. This title means that the Google Basemap does not vector-draw on the client side (usually the browser), but instead generates a map tile at each zoom level on the server, and the client requests the map image via Ajax technology and renders the presentation on the client. This article's several answers basically has explained the reason, here is not to repeat, the concrete can see the original text. on the present situation of Web map vector rendering application

About 3 years have not touched the GIS, after seeing this topic, suddenly want to see the current web map using a client-side vector rendering or raster map. So I looked at the following several maps on the PC side of the situation (mobile may be different, only know that the latest SDK is vector data, note that this does not refer to the mobile browser, but the mobile side native vector rendering): Google Maps Baidu map of the German map Tencent map OpenStreetMap

in writing this article came to the conclusion that this (be sure to note that today's situation is this, does not mean that forever, the future technology will certainly change):

The basemap uses vector rendering with Google Maps, a German map.
The BASEMAP uses a raster map with Baidu Maps, Tencent maps, and OpenStreetMap.

As a result, Google Maps did not use the client-side vector rendering technology in the 2012, and now it is used. At home, the German map is a more forward-looking way. The main reason for the widespread use of pyramid-based raster data was the lack of browser vector rendering capabilities and the compatibility and diversity of browsers, and the use of raster mapping techniques in order to achieve a consistent cross-browser experience. With the maturity of HTML5 technology and the better support of browser to HTML5, the performance of client vector rendering is not a bottleneck, so more and more web maps are used in the way of browser-side vector rendering technology or vector-grid combination.

Vector rendering contrasts the benefits of raster maps in the following ways: Data updates are faster and more timely-because geographic data is a massive level, making map slices can take hours, days, or longer, while client-side vector rendering can theoretically support real-time updates. Free up the client's cache space, save traffic-the original client needs to cache a large number of map tiles, while vector rendering only needs to transmit Geojson string, greatly saving traffic, which is particularly important on the mobile side. The client supports vector editing-in the past, it is not possible to edit the data at the client only for picture presentation.

Of course, there is no denying that client-side vector rendering brings some security risks, and it is easy to get map data by grabbing packets, which is a problem to consider. on the problem of remote sensing imagery

First of all the remote sensing image data are raster technology, generated by the server slice, the client asynchronous request load.

By testing the above several maps, found that the domestic remote sensing data are done in the post-processing, some important areas of data (such as military bases) are not found in remote sensing images, and Google's remote sensing images can even clearly see warships, want to experience a way to visit Google. In addition, Google's remote sensing imagery and map overlay is biased, this is because Google Maps in China is partly using the high-gold data (already the national Mars coordinate system, for reasons you understand), Baidu map and the high-gold map is not biased because they have been corrected bias. about indoor positioning

When opening the high-D map open platform, we found the indoor positioning technology solution provided by http://lbs.amap.com/getting-started/indoorlocation/, the document address is.

Today, indoor map and indoor positioning of the demand for more and more, because the interior map requires more precision, there are some professional production of indoor map of the company. Indoor positioning technology is mainly based on wifi and Bluetooth, so the indoor hardware conditions and mobile device version requirements are relatively high, such as the need for on-site indoor WiFi or ibeacon information, and even how to lay out WiFi or ibeacon equipment on site have stringent requirements; for mobile phones, Bluetooth enabled versions , the system version is required. In this way, the cost and complexity of indoor positioning is still relatively high, more relevant information can be seen in the German indoor positioning scheme. other

Several browser-side vector rendering examples and renderings on the GIS Cloud are very good http://www.giscloud.com/map/16671/a-world-of-a-million-points/HTTP/ Www.giscloud.com/map/12584/sarasota-parcels Http://www.giscloud.com/map/16594/germany-6000000-features

leaflet An open source JavaScript map library that supports drawing vector layers GitHub Address: Https://github.com/Leaflet/Leaflet

GeoJson JSON format specification for map data, such as how dots, lines, and polygons are represented by JSON: http://geojson.org/

MapBox An open source mapping platform for custom designed maps. Website address: https://www.mapbox.com/

Global Top ten Map API Google maps API Bing Maps API Openlayers API Foursquare API OpenStreetMap API MapQuest API M Apbox API Cartodb API Esri ArcGIS API Yahoo BOSS Placefinder API