on September 28, 2022

Public sources of topographical data of Earth?

Earth science

Asked by: Steve Hlavaty

Where can I get topography data?

Topographic data are information about the elevation of the surface of the Earth.



Digital Raster Graphics

  • USGS Earth Explorer.
  • USGS Seamless Server.
  • USDA Geospatial Gateway (more info)


What is the source of the elevation data?

Ground survey is the oldest source of elevation data, traditionally undertaken by leveling and triangulation (see below). A ground survey allows the area of interest to be observed at close range, and the survey tailored to record the most relevant information, such as ridges, peaks and troughs.

Which data are shown on topographic maps?

Topographic maps show contours, elevation, forest cover, marsh, pipelines, power transmission lines, buildings and various types of boundary lines such as international, provincial and administrative, and many others.

What do topographic maps use as their main source of information?

The distinctive characteristic of a topographic map is the use of elevation contour lines to show the shape of the Earth’s surface. Elevation contours are imaginary lines connecting points having the same elevation on the surface of the land above or below a reference surface, which is usually mean sea level.

How is topography data collected?

The collection of the digital information about a contour lines and topographic objects is carried out by DWS-stereo, analytical plotters Stereoanagraph or SD-20 in DWS (Win- dows and DOS) 3D-format. The data can be transferred (if necessary) to other widespread formats (DXF/DBF, MID/MIF).

How do you check topography?

Quote from video: I mean really you can pick any pinpoint on the globe and zoom in on that and see exactly what the elevations look like so obviously. This is pretty helpful if you're trying to figure out.

What kind of data type is elevation?

Solution: Elevation is in meters and is therefore a numeric data type.



What type of data is elevation?

Continuous data



Examples of continuous surfaces are elevation, aspect, slope, the radiation levels from a nuclear plant, and the salt concentration from a salt marsh as it moves inland.

What type of data is elevation in GIS?

Digital elevation data are sets of elevation measurements for locations distributed over the land surface. Elevation data have many practical uses ranging from environmental to urban. Slope and aspect can be directly derived from elevation. Stream delineation and subsequently watershed boundaries can also be derived.

What are the types of topography?

Topography Types

  • Karst Topography. Karst topography describes the distinct landscape that is made when underlying rocks dissolve or change shape. …
  • Mountain Topography. Topographical maps show landforms such as hills and mountains. …
  • Vegetation, Elevation and Glaciers.


What are the different types of topographic maps?

What are the Different Classes of Topographic Maps ?



  • Large scale: larger than 1:25 000.
  • Medium scale: 1:25 000 to approximately 1:250 000.
  • Small scale: smaller than 1:250 000 to approximately 1:2 500 000.
  • Very small scale: smaller than 1:2 500 000, usually atlas-maps.


What are the two types of scales found on topographical maps?

There are two main types of map scales: bar and lexical.

How do you conduct a topographic survey?

A typical topographic plan includes the following steps:



Establishing horizontal and vertical control that will serve as the framework of the survey. Determining enough horizontal location and elevation (usually called side shots) of ground points to provide enough data for plotting when the map is prepared.

What is a topographic survey?

A topographical survey is broadly defined as recording the coordinates and elevation (height) data of natural and artificial features within a designated survey area. An elaboration of this definition includes: The surveyed points are mapped in three dimensions related to the national grid system and datum information.



What are topographic surveys used for?

Topographic land survey measures and identifies accurate locations and specifications of natural and human characteristics within a territory. The survey is then compiled into a suitable and detailed schedule which includes human-made features such as borders, neighboring buildings, footbridges, etc.

Where can I download GIS data?

10 Free GIS Data Sources: Best Global Raster and Vector Datasets

  • 10 Free GIS Data Sources. We live in the information age. …
  • Esri Open Data Hub. …
  • Natural Earth Data. …
  • USGS Earth Explorer. …
  • OpenStreetMap. …
  • NASA’s Socioeconomic Data and Applications Center (SEDAC) …
  • Open Topography. …
  • UNEP Environmental Data Explorer.

How do I extract terrain from Google Earth?

About This Article

  1. Install Google Earth Pro.
  2. Download a topographical map in the KML or KMZ format.
  3. Open Google Earth Pro.
  4. Click the File menu and select Open.
  5. Select the KML or KMZ file and click Open.
  6. Zoom in to see the contour lines.


How do I download data from OpenTopography?

To access bulk data download, log into OpenTopography and navigate to your dataset of interest. A “bulk download” link is visible on the dataset metadata landing page and above the point cloud and raster data download and processing maps.



What is digital topographic map?

Digital topographic maps (DTK) offer geo-topographical base information in the form of digital raster data. They are updated and provided by the survey agencies of the states and the Federal Agency for Cartography and Geodesy (BKG) at scales 1 : 25,000 to 1 : 1,000,000.

Can Google maps show topography?

Google Maps now has Terrain View, which enables users to see terrain maps for an area. Terrain view shows the 3D elevation of natural geographic features, such as mountains and canyons. Topographic contour lines are overlaid on the map to show elevation levels with altitude information displayed in gray numbers.

What three factors are shown on a topographic map?

Topographic maps identify numerous ground features, which can be grouped into the following categories: Relief: mountains, valleys, slopes, depressions as defined by contours. Hydrography: lakes, rivers, streams, swamps, rapids, falls. Vegetation: wooded areas.