Geoid Gallery

 

 

Entire planet

Geoid model: EIGEN6C, Gridstep: 0.1°
Filter type: Gaussian, halfresponse, Filter length: 5°
Projection: Geographic, Graticule interval: 12°

 

Entire planet

Geoid model: EIGEN6C, Gridstep: 0.1°
Filter type: Gaussian, halfresponse, Filter length: 0.1°
Projection: Geographic, Graticule interval: 12°

 

Indian and Pacific Oceans

Geoid model: EIGEN6C, Gridstep: 0.1°
Filter type: Gaussian, halfresponse, Filter length: 0.1°
Projection: Geographic, Graticule interval: 12°

 

The Americas

Geoid model: EIGEN6C, Gridstep: 0.1°
Filter type: Gaussian, halfresponse, Filter length: 0.1°
Projection: Geographic, Graticule interval: 12°

 

North America

Geoid model: EIGEN6C, Gridstep: 0.06°
Filter type: Gaussian, halfresponse, Filter length: 0.1°
Projection: Mercator, Graticule interval: 12°

 

The Gulf of Maine

Geoid model: EIGEN6C, Gridstep: 0.01°
Filter type: Gaussian, halfresponse, Filter length: 0.1°
Projection: Mercator, Graticule interval: 1°

 

Western North America

Geoid model: EIGEN6C, Gridstep: 0.1°
Filter type: Gaussian, halfresponse, Filter length: 0.1°
Projection: Albers Conic, Graticule interval: 12°

 

Africa to Australia

Geoid model: EIGEN6C, Gridstep: 0.1°
Filter type: Gaussian, halfresponse, Filter length: 0.1°
Projection: Mercator, Graticule interval: 12°

 

Aleutian Trench

Geoid model: EIGEN6C, Gridstep: 0.03°
Filter type: Gaussian, halfresponse, Filter length: 0.1°
Projection: Mercator, Graticule interval: 3°

 

Izu Bonin Mariana Arc

Geoid model: EIGEN6C, Gridstep: 0.02°
Filter type: Gaussian, halfresponse, Filter length: 0.1°
Projection: Geographic, Graticule interval: 3°

 

Equatorial Slice

Geoid model: EIGEN6C, Gridstep: 0.03°
Filter type: Gaussian, halfresponse, Filter length: 0.05°
Projection: Geographic, Graticule interval: 12°

 

Diving Laccadive Sea

Geoid model: EIGEN6C, Gridstep: 0.02°
Filter type: Gaussian, halfresponse, Filter length: 0.05°
Projection: Geographic, Graticule interval: 5°

 
All rendered images of the geoid shown in this gallery are predicated upon the data generated by GFZ Potsdam and in particular, the latest combined model EIGEN6C, using GFZ’s online calculation service. Additionally, all datasets have utilized a Gaussian filter to help smooth things out a bit. For a comparison, a single dataset used the filter length of 5° – you should be able to pick out it’s extra smooth surface from the line up of these illustrations. This particular model (EIGEN6C) combines the latest GOCE data plus other data from altimetry and terrestrial sources.

The geoid’s basic spherical shape was defined using a grid step interval of 0.1° in both latitude (φ, phi) and longitude (λ, lambda) resulting in 6,485,401 grid points for the entire surface. In other illustrations zoomed in at closer levels, the gridstep intervals were even closer, the values of which are indicated on each illustration.

Many thanks to the amazing online services provided by the GFZ German Research Centre for Geosciences at the Helmholtz Centre Potsdam and to Franz Barthelmes for his kind support.

All spatial content and its associated mapping (including these illustrations of the geoid!) was done using the software program Global Mapper. Many thanks go out to Mike Childs of Blue Marble Geographics for his tremendous support.

Because the surface of the geoid is fairly complex, no single light source satisfactorily illuminated the subject. To improve the overall illumination, multiple (varies between 3 and 5) renderings of the exact scene were done using different lighting azimuths and altitudes and then combined using Oloneo’s incredible Relight module in Photo Engine which allowed each lighted scene to be dimmed or brightened independently of each other to achieve the desired effect. Additional graphic embellishments (curves, toning, etc.) were done using Adobe’s Photoshop, CS6.

 Posted by on August 29, 2012 at 6:06 pm