Posts Tagged ‘srtm’

German TanDEM-X satellite seeks 3D view of Earth (BBC)

Wednesday, June 23rd, 2010

_48126100_00_tandem-x_dem_h_henmodell

[Editor’s note: Second of a pair of new satellites, now operational, will build higher resolution (with more vertical precision) view of Earth than prior SRTM efforts (90m free, 30m restricted). Graphic shows the same area in different DEM (DTM) resolutions. The 12 meter pixel size of the new commercial project is global, but inconsistent with the 10 meter DEMs available in the United States. Thanks Thierry_G!]

Republished from the BBC.

The TanDEM-X satellite has blasted into orbit on a mission to acquire the most precise 3D map of the Earth’s surface. The German radar spacecraft will fly in formation with an identical platform called TerraSAR-X launched in 2007. Together, the pair will measure the variation in height across the globe to an accuracy of better than two metres. Their digital elevation model will have myriad uses, from helping military jets fly ultra low to showing relief workers where an earthquake’s damage is worst.

“Our aim is to generate a model at a resolution and a quality that doesn’t exist today,” explained Dr Vark Helfritz, from satellite image-processing company Infoterra GmbH. “This will be a truly seamless global product – not a patchwork of datasets that have been fitted together,” he told BBC News. TanDEM-X was carried into space atop a converted intercontinental ballistic missile from the Baikonur Cosmodrome in Kazakhstan.

Continue reading at the BBC . . .

Adding new rivers and lakes to 10m Natural Earth in North America

Tuesday, January 19th, 2010

Tom and I have been busy adding 4 times the rivers and 3 times the lakes we had for North America. This adds in many “missing” hydro features that one might normally find on a 1:10,000,000 hydrologic reference map.

Why were they missing from the first version of Natural Earth? It’s hard to wade thru 1:1,000,000 features to figure which to add and an even tougher job to attribute them with the correct name and scale ranks. There’s another factor: these extra features are great if you’re making a watershed map, but can be a little noisy when used as a background layer in say a political reference map.

Cody Rice, now of the EPA but formerly of the Commission for Environmental Cooperation (CEC) send along an amazing link last week. The CEC is a joint agency between the United States, Canada, and Mexico. Specifically: USGS, Natural Resources Canada, INEGI-Mexico. Each country contributed base data for a 1:10,000,000 digital atlas. The data is available in many popular formats and is in the public domain. Better yet, it includes GIS data attributes like river name!

We’ve compared with our existing Natural Earth linework and identified which features were missing. For those we’re adding, we’ve adjusted the new linework a nudge here and there so it lines up with SRTM relief and our existing linework. We’ve also gone thru and created lake centerlines and applied scale ranks to all in three new steps (10, 11, and 12). We have some final polishing but will be releasing, along with some slight adjustments to the original data, by the end of January.

Do you have time to donate? Unlike ranks 0 to 9 (the original data), this new data will NOT come tapered. We’d like it to be and can show you how.

Know of a similar, attributed with name, 1:10,000,000 regional dataset we could adapt into Natural Earth to build out our coverage? Please let me know at nathaniel@kelsocartography.com.

Preview images below:

Red = new at rank 10. Blue = new at rank 11. Black = new at rank 12. Grey = old at ranks 0 to 9.

Click images to view larger sizes.

hydro_west_coast

hydro_mid_west

hydro_east

hydro_mexico

hydro_alaska

hydro_yukon

hydro_quebec

New Global 30m DEM Topographic Data via ASTER (NASA)

Tuesday, June 30th, 2009

pia12090-browse

[Editor’s note: NASA and Japan’s Ministry of Economy, Trade and industry (METI) released new 30 meter resolution Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM) to the worldwide June 29, 2009. The new dataset covers the high latitudes with increased precision over SRTM, although the cloud cover problems that plauge ASTER can prove problematic. The servers were being hit heavy on Monday and data download is convoluted. The preview of the data uses a curious data exploration color ramp with inverted shading. Thanks Tom and Laris!]

Republished from NASA.

PASADENA, Calif. – NASA and Japan released a new digital topographic map of Earth Monday that covers more of our planet than ever before. The map was produced with detailed measurements from NASA’s Terra spacecraft.

The new global digital elevation model of Earth was created from nearly 1.3 million individual stereo-pair images collected by the Japanese Advanced Spaceborne Thermal Emission and Reflection Radiometer, or Aster, instrument aboard Terra. NASA and Japan’s Ministry of Economy, Trade and Industry, known as METI, developed the data set. It is available online to users everywhere at no cost.

“This is the most complete, consistent global digital elevation data yet made available to the world,” said Woody Turner, Aster program scientist at NASA Headquarters in Washington. “This unique global set of data will serve users and researchers from a wide array of disciplines that need elevation and terrain information.”

According to Mike Abrams, Aster science team leader at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., the new topographic information will be of value throughout the Earth sciences and has many practical applications. “Aster’s accurate topographic data will be used for engineering, energy exploration, conserving natural resources, environmental management, public works design, firefighting, recreation, geology and city planning, to name just a few areas,” Abrams said.

Previously, the most complete topographic set of data publicly available was from NASA’s Shuttle Radar Topography Mission. That mission mapped 80 percent of Earth’s landmass, between 60 degrees north latitude and 57 degrees south. The new Aster data expand coverage to 99 percent, from 83 degrees north latitude and 83 degrees south. Each elevation measurement point in the new data is 30 meters (98 feet) apart.

“The Aster data fill in many of the voids in the shuttle mission’s data, such as in very steep terrains and in some deserts,” said Michael Kobrick, Shuttle Radar Topography Mission project scientist at JPL. “NASA is working to combine the Aster data with that of the Shuttle Radar Topography Mission and other sources to produce an even better global topographic map.”

NASA and METI are jointly contributing the Aster topographic data to the Group on Earth Observations, an international partnership headquartered at the World Meteorological Organization in Geneva, Switzerland, for use in its Global Earth Observation System of Systems. This “system of systems” is a collaborative, international effort to share and integrate Earth observation data from many different instruments and systems to help monitor and forecast global environmental changes.

NASA, METI and the U.S. Geological Survey validated the data, with support from the U.S. National Geospatial-Intelligence Agency and other collaborators. The data will be distributed by NASA’s Land Processes Distributed Active Archive Center at the U.S. Geological Survey’s Earth Resources Observation and Science Data Center in Sioux Falls, S.D., and by METI’s Earth Remote Sensing Data Analysis Center in Tokyo.

Aster is one of five Earth-observing instruments launched on Terra in December 1999. Aster acquires images from the visible to the thermal infrared wavelength region, with spatial resolutions ranging from about 15 to 90 meters (50 to 300 feet). A joint science team from the U.S. and Japan validates and calibrates the instrument and data products. The U.S. science team is located at JPL.

For visualizations of the new Aster topographic data, visit: http://www.nasa.gov/topics/earth/features/20090629.html .

Data users can download the Aster global digital elevation model at: https://wist.echo.nasa.gov/~wist/api/imswelcome and http://www.gdem.aster.ersdac.or.jp .

For more information about NASA and agency programs, visit: http://www.nasa.gov .

JPL is managed for NASA by the California Institute of Technology in Pasadena.

ISO global road, rail shapefile (Kelso)

Monday, March 30th, 2009

I’m in search of a super generalized but comprehensive global coverage dataset or datasets that shows major highways and rail lines, even sea lanes. You can see an example of this on Plate 21 of the National Geographic 8th Edition Atlas of the World. Do you know of one? Please shoot me a note to nathaniel@kelsocartography.com or comment here if you have a tip.

Why do I want such? I am working with Tom Patterson (of Natural Earth fame) and Dick Furno (retired from The Washington Post) to release a comprehensive, attributed GIS base map dataset derived in part from the Natural Earth physical wall map at around 1:15,000,000 scale and two other consistent and self referential datasets at approx. scales of 1:50m and 1:110m. These datasets will provide coverage that perfectly registers with the modern satellite remote sensing imagery and SRTM derived topography. Yes there is 1:1m coverage around the world but it is often out of date and too detailed for doing global, continental, and regional mapping.

We hope these open source datasets will allow everyone in the cartographic community to focus on telling the best “why” and “how” visual story about their thematic data instead of spending 50 to 70% of project time looking for or creating the vector geometry that captures the basic “where” of their thematic data.

Release is expected Fall 2009 at the NACIS map conference in Sacramento. Please check back in this space for more details as they develop.

See SRTM Satelite at Smithsonian’s Udvar-Hazy Center!!! (Kelso)

Friday, February 27th, 2009

I went out to the Smithsonian’s Udvar-Hazy Air and Space museum annex at Dulles International Airport in Chantilly, Virginia last weekend and was pleasantly surprised to see one of the SRTM payloads hanging off the ceiling. The Shuttle Radar Telemetry Mapping program helped produce a significantly more accurate and detailed world-wide digital elevation model (DEM, DTM) in the early part of this decade and was a great leap forward for shaded relief generation. If you make the trip, you’ll find the SRTM between 22 and 23 on the map below in the “space shuttle” hanger. The map does a good job of indicating what altitude different aircraft can be found in the hanger.

Here’s a photo:

Cannister/Mast, Shuttle Radar Topography Mission Payload
(republished from the Smithsonian)
In 2000, the Shuttle Endeavor carried the Shuttle Radar Topography Mission (SRTM) payload into orbit. Shuttle astronauts used the payload, manufactured by the AEC-Able Engineering Co., to map in high detail and three dimensions more than 70 percent of the Earth’s surface–the most complete and accurate rendering of the planet’s land masses ever attempted. The Museum possesses two components–the mast canister (this artifact) and the outboard support structure with its antennas–crucial to that mission.

To acquire this data, the SRTM used a novel hardware system that featured a main antenna located in the Shuttle payload bay, a folding mast (in the mast canister) that extended 60 meters from the Shuttle, and then another antenna system that was positioned at the end of the mast (the outboard structure). It was this dual antenna system–the largest rigid structure then flown in space–that produced, through interferometry (a technique for combining the information obtained from the two, separate antennas), a three-dimensional mapping of the Earth.

The mission was a joint undertaking of NASA’s Jet Propulsion Laboratory and the Department of Defense’s National Imagery and Mapping Agency. The military will use the highest resolution data from SRTM for terrain navigation for planes and cruise missiles. A lower resolution data set will be made available to civilian scientists and other users.

NASA transferred these artifacts to the Museum in 2003.

Transferred from NASA
Manufacturer: AEC-Able Engineering Co.
Country of Origin: United States of America
Dimensions:
Overall: 292.1 length x 136cm diameter, 984.3kg weight (9ft 7in. x 4ft 5 9/16in., 2170lb.)
Materials:
Aluminum, steel, titanium, plastic, copper
Inventory Number: A20040261000

General layout of the museum:

Panorama, Peak Identification And Viewsheds In Google Earth (Free Geography Tools)

Wednesday, July 23rd, 2008

free geo tools logo[Editor’s note: This is the website for the “Hey, What’s That” tool featured in the Where iPod app reviewed in this blog last week.]

Reprinted from Free Geography Tools blog (posted there March 14, 2007).

OgleEarth posts about Hey, What’s That?, a website that lets you enter a location and then gives you:

  • A panorama of what’s visible from that location, marking the position of peak geographic landmarks
  • A list of the peaks, and the ability to show their position relative to your location on Google Maps
  • Terrain profiles (elevation versus distance from the location to any point on the map)
  • A plot all the areas visible from that location in red on Google Maps (aka the “viewshed” or “weapons fan”)
  • Contour lines (zoom in for these)
  • Google Earth export of position, viewshed, horizon line and horizon extent. If the viewshed area is large, this might strain the memory capacity of lesser systems.

It uses 30-meter SRTM version 1 data for its calculations, so there may be some quirks depending on whether there are holes in the SRTM coverage for your area. They’re switching over to SRTM version 2 soon, which is better but still not perfect. It only works in the US right now, but according to OgleEarth, they hope to expand coverage worldwide. A cool site! Check the OgleEarth posting for more info.

GISLook & GISMeta – Preview GIS Data Before Opening It

Thursday, June 26th, 2008

 gis quick look plugin bernie

Using Quick Look in Mac OS X 10.5, you can view the contents of a file without even opening it.

I am proud to announce today that Mr. Genius Bernhard Jenny of the Swiss Institute of Cartography at ETH Zurich has created Quick Look and Spotlight plugins for GIS data for Leopard. Download here.

Use GISLook to browse and preview GIS data in Finder window thumbnails, including Cover Flow and Quick Look windows. Use GISMeta to view the size of GIS raster grid files.

If you haven’t upgraded to 10.5 yet, this is good reason. If you don’t own a Mac, get one and run ArcMap  via Parallels Desktop.

This software is donationware. You can freely use them at no charge. If you use them regularly, it is suggested that you pay a donation of €5 or a more suitable amount.

Supported file types include: 

Vector data

  • ESRI Shape (.shp)
  • E00 ArcInfo Interchange (.e00)
  • ArcInfo Coverage (.adf)

Raster grids, such as digital elevation models or land cover data with a single band

  • BIL (.bil), BIP (.bip) and BSQ (.bsq) with .hdr file
  • ESRI ASCII Grid (.asc)
  • ESRI Binary Grid (.flt with .hdr file)
  • PGM (.pgm)
  • SRTM (.hgt and .dem)
  • Surfer Grid (.grd)
  • USGS DEM (.dem)