What is the KML file extension? How to open a KMZ file Kml file.

The most common problem that prevents users from opening this file is an incorrectly assigned program. To fix this in Windows OS you need to right-click on the file, in context menu Hover your mouse over the "Open with" item and select "Select a program..." from the drop-down menu. As a result you will see a list installed programs on your computer, and you can choose the appropriate one. We also recommend checking the box next to “Use this application for all KML files.”

Another problem that our users also encounter quite often is that the KML file is corrupted. This situation can arise in many cases. For example: the file was downloaded incompletely as a result server errors, the file was damaged initially, etc. To fix this problem, use one of the recommendations:

• Try to find required file in another source on the Internet. You may have luck finding a more suitable version. Example Google search: "File filetype:KML" . Just replace the word "file" with the name you want;
• Ask them to send you original file again, it may have been damaged in transit;

Tip: To see the KML "code" for a feature in Google Earth, you can simply right-click the feature in the 3D Viewer of Google Earth and select Copy. Then Paste the contents of the clipboard into any text editor. The visual feature displayed in Google Earth is converted into its KML text equivalent. Be sure to experiment with this feature.

For a discussion of how to use some of the key features in KML, see the Developer's Guide.

Table of Contents

Basic KML Documents

The simplest kind of KML documents are those that can be authored directly in Google Earth—that is, you don"t need to edit or create any KML in a text editor. Placemarks, ground overlays, paths, and polygons can all be authored directly in Google Earth.

Placemarks

A Placemark is one of the most commonly used features in Google Earth. It marks a position on the Earth's surface, using a yellow pushpin as the icon. The simplest Placemark includes only a Element, which specifies the location of the Placemark. You can specify a name and a custom icon for the Placemark, and you can also add other geometry elements to it.

As an example, enable the "Absolute Positioning: Top left" folder in the KML Samples file and you will see a screen overlay at the top left of the view window. This was created with the following KML code:

Absolute Positioning: Top left

http://site/kml/documentation/images/top_left.jpg

Positioning is controlled by mapping a point in the image specified by to a point on the screen specified by . In this case, the top-left corner of the image (0,1) has been made coincident with the same point on the screen.

Check the other examples in the folder to see how it is possible to obtain other fixed positions, and to create images that size dynamically with screen size. (Note that xunits and units can also be specified as "pixels" for precision control.) For further detail, see the KML 2.2 Reference .

Network Links

A network link contains a element with an (a hypertext reference) that loads a file. The can be a local file specification or an absolute URL. Despite the name, a does not necessarily load files from the network.

The in a link specifies the location of any of the following:

• An image file used by icons in icon styles, ground overlays, and screen overlays
• A model file used in the element
• A KML or KMZ file loaded by a Network Link

The specified file can be either a local file or a file on a remote server. In their simplest form, network links are a useful way to split one large KML file into smaller, more manageable files on the same computer.

So far, all of our examples have required that the KML code be delivered to Google Earth from the local machine. Network links give you the power to serve content from a remote location and are commonly used to distribute data to large numbers of users. In this way, if the data needs to be amended, it has to be changed only at the source location, and all users receive the updated data automatically.

CGI Scripting for KML

In addition to pointing to files containing static data, a network link"s can point to data that is dynamically generated—for example, by a CGI script located on a network server. With some knowledge of a scripting language such as PHP, Python, or Perl, you can create a script that delivers a stream (or file) of KML data to each network link.

Two things are necessary for delivering KML through a network CGI:

When a call is made from the client (Google Earth) to the server, the server must (1) return a response code of HTTP 200 and (2) set the response"s content type to text/plain or application/vnd.google -earth.kml+xml.

The response must be valid KML. For complex applications, proper error handling is very important.

Tip: A simple way to handle errors is to parse the server"s error as the text for a folder name. For example, you could have the server return database inaccessible as a string. This is more informative (and more user-friendly) than letting the connection drop.

The following examples use Python, but they are equally valid in any other scripting language.

Generating a Random Placemark

The following Python script generates random integer values ​​for latitude and longitude and then inserts those values ​​into the element of a Whenever the network link is refreshed, the Python script runs again and generates KML with new latitude and longitude values.

#!/usr/bin/python import random latitude = random.randrange(-90, 90) longitude = random.randrange(-180, 180) kml = ("\n" " \n" " \n" " Random Placemark\n" " \n" " %d,%d\n" "\n" "\n" "") %(longitude, latitude) print "Content-Type: application/vnd.google-earth.kml+xml\n" print kml

Here is an example of a KML file containing a Network Link that loads this Python script:

Network Links
0
0
Network link example 1

Random Placemark
0
0
A simple server-side script that generates a new random
placemark on each call
0
0

http:// yourserver.com/cgi-bin/randomPlacemark.py

View-Based Refresh Queries

A standard network link is a uni-directional link: data flows only from the server to Google Earth. The view-based refresh enables bi-directional communication. When the view-based refresh is active, Google Earth returns the view coordinates to the server at a specified time. This may be every n seconds, minutes, or hours, or once a certain amount of time has elapsed since the view stopped moving. See in the KML 2.2 Reference.

The coordinates are returned to the server by means of an HTTP GET that appends the coordinates as follows (this is the default bounding box information):

GET /path/to/sever/script/query?BBOX= HTTP/1.1

If the request were made while the user was looking down on San Francisco, the coordinates might look as follows:

GET /path/to/server/script/query?BBOX=-122.497790,37.730385,-122.380087,37.812331 HTTP/1.1

This feature can be used for some very creative applications, but to get you started, a simple example is presented below.

Tracking a Point Directly Under Your View

The following server-side Python script parses the return message sent by Google Earth and responds with a Placemark at the center of the screen. Each time the Network Link is refreshed, a new Placemark is generated.

#!/usr/bin/python import cgi url = cgi.FieldStorage() bbox = url["BBOX"].value bbox = bbox.split(",") west = float(bbox) south = float(bbox) east = float(bbox) north = float(bbox) center_lng = ((east - west) / 2) + west center_lat = ((north - south) / 2) + south kml = ("\n" " \n" " \n" " View-centered placemark\n" " \n" " %.6f,%.6f\n" "\n" "\n" "") %(center_lng, center_lat) print "Content-Type: application/vnd.google-earth.kml+xml\n" print kml

And here is the KML for the Network Link that loads the Python script:

Network Links
0
0
Network link example 2

View Centered Placemark
0
0
The view-based refresh allows the remote server to calculate
the center of your screen and return a placemark.
0
0

http:// yourserver.com/cgi-bin/viewCenteredPlacemark.py
2
onStop
1

The principle illustrated in this example can be used for some very complex applications. For example, if you have a database of geographic information, you can extract the coordinates of the viewer, make a call to the database for the data specific to the view, and return it to Google Earth as KML.

3 KML MIME Types

When responding to a request from Google Earth (or any Earth browser), a KML server must follow a certain set of rules so that Google Earth can correctly interpret its responses.

Upon success, the server must return a response code of HTTP 200 and set the response"s content-type to a suitable MIME type, as described here.

Google Earth reads KML and KMZ files. The MIME type for KML files is

• application/vnd.google-earth.kml+xml

The MIME type for KMZ files is

• application/vnd.google-earth.kmz

For Apache, add these lines to the httpd.conf file:

• AddType application/vnd.google-earth.kml+xml .kml
• AddType application/vnd.google-earth.kmz .kmz

See the Microsoft documentation for details on setting up MIME types on Microsoft's IIS.

The body of the response must contain valid KML data, including the XML declaration (). If the server returns invalid KML, the Network Link will stop, deactivate, and output an error message.

A KML file stores geomodeling data in XML format. It contains points, lines and images. Use XML to express geographic annotation and visualization by storing locations, image overlays, video links, and modeling information such as lines, shapes, 3D images, and points. Various geospatial software solutions use the KML format to put data into a format that other programs and web services can easily use.

Introduction

Keyhole Markup Language - An XML notation for expressing geographic annotation and visualization in 2D maps and 3D browsers. KML was developed for use with Google Earth, which was originally called Keyhole Earth Viewer. It was created by Keyhole. Inc, which was acquired by Google in 2004. This format became international standard Open Geospatial Consortium in 2008.

Google Earth was the first program capable of viewing and graphically editing such files. Other projects, such as Marble, have also begun to develop KML support.

Application: How to create KML format?

You can open a file with this extension in Google Maps. To do this, you need to post its location online and then enter the URL into the Google Maps search box.

Google Earth was the first program that could view and edit these files, and it remains one of the most popular ways for working with geodata on the Internet. With a web page open, use the My Places menu item (bookmark icon) to upload a KML file from your computer or account Google Drive.

You can also open files using any text editor(eg Notepad++). This will allow you to see a text version that includes coordinates, image links, camera angles, and timestamps.

If you want to convert KML to XML, you don't need to do the conversion. Since the format is actually just using the KML format extension), you can rename .KML to .XML so that it will be opened in your XML viewer.

You can also import the file directly into Google Maps. This is done on Google page My maps when adding content to a new map layer. With the map open, select Import at any level to upload the file from your computer or Google Drive. You can create a new layer using the Add Layer button.

You can also create your own KML file and its URL in Google Maps by first linking your file's URL using http://maps.google.com/maps?q=. For example, to open the same address, you can use the following URL: http://maps.google.com/maps?q=http://mywebsite.com/myfile.kml.

This operation also works for Google Earth, a 3D plugin for viewing our planet that can be added to a web browser.

Structure

The KML file format specifies a set of functions (labels, images, polygons, 3D models, text descriptions) for display in Google Maps, Google Earth, Maps, on mobile devices or any other geospatial software, which implements the KML encoding. Each location has a longitude and latitude. This format shares some of the same structural grammars as GML. Some information cannot be viewed in Google Maps or on mobile devices.

Data is very often distributed in KMZ format, which are encrypted KML files with a .kmz extension. They must be compatible with legacy (ZIP 2.0) compression, otherwise the .kmz file may not decompress.

Geodetic reference systems in KML

For its reference frame, KML uses 3D geographic coordinates: longitude, latitude, and altitude. Longitude, latitude components (decimal degrees) are determined in accordance with the World Geodetic System 1984 (WGS84). The vertical component (height) is measured in meters from the vertical base of the WGS84 EGM96 Geoid. If the altitude is not specified in the coordinate string (for example, -77.03647, 38.89763), then the altitude component is assumed to have a default value of 0 (approximately sea level), that is, (-77.03647, 38.89763, 0).

The formal definition of the coordinate system (coded as GML) used in KML is contained in the OGC KML 2.2 specification. This definition refers to the components of the EPSG CRS.

Documentation

The KML 2.2 specification was submitted to the Open Geospatial Consortium to ensure its status as an open standard for all geospatial objects. In November 2007, a new OGC was created working group to formalize the standard. Comments on the proposed standard were solicited until January 4, 2008, and it became an official OGC standard on April 14, 2008.

The Standards Working Group has finalized the KML 2.2 change requests and included accepted changes. The official OGC KML 2.3 standard was published on August 4, 2015.

Announcement

KML Misc File Format

KML files are stored in XML format and were originally developed for the Keyhole mapping program. In 2004 Google company bought Keyhole Inc., and that is why KML files are now actively used Google services related to cartography - Google Maps and Google Earth.

Technical information about KML files

KML files contain information that is stored in XML format. This information includes both images and simpler data - lines, polygons and points. Such files are used to store information about a specific location on the map. The KML file allows the user not only to mark a location on the map, but also to add content (in HTML format), texture and appearance different angles. To open KML files in Google Maps, all that is required is the KML file itself, hosted on the Internet. Using a separate extension link in line Google search Maps will open it.

Additional information about the KML format

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