Can be displayed on the sphere. An example of this is a global image of the Age
of the Seafloor. It’s a static image that can be manipulated and rotated in
real time from the user interface or remote control.
Animates through time. An example of this would be a loop of satellite data.
For an image sequence, SOSx will display the images in sequence and play them
like a movie across the entire sphere surface at a pre-determined fps (frames
per second). Image sequences can be of any arbitrary length, limited mainly by
disk space and can be animated at frame rates up to 60 frames per second.
MPEG4’s save disk space but do not show time on SOSx. This means that we cannot
display the date and time for data using an MP4. We suggest using Time Series
for datasets where date and time are needed. Transitions, audio, special
effects, and other computer graphics techniques can be added to a sequence
through the use of off the shelf software like Final Cut Pro.
Use the equatorial cylindrical equidistant projection. This is a simple
latitude/longitude grid with the lines evenly spaced where the image is twice
as wide as it is tall. To be consistent with the SOS Data Catalog, it is
recommended that the 0° line go through the middle of the map, with the +/-180°
lines at the edges.
The software also has the ability to display KML (Keyhole Markup Language) and
the compressed KMZ files on SOSx. KML is a popular specification and actively
used with Google Earth for displaying data on a sphere.
4096×2048 for animations, 8192×4096 for single images (textures).
Those are the recommended resolutions, though other 2x1 resolutions, such as
3000x1500 will work. We recommend a minimum of 2K for any dataset. Datasets
with very high resolution and progressive disclosure tiles can also be added.
Email firstname.lastname@example.org for more
The data should take up the whole image, with no borders or extra space around
the edges. Even a pixel border will show up as a seam! In most cases, a
simple 1% stretch in the horizontal will fix the problem. The data should
match up at the edges of the image. If it doesn’t, a seam will appear where
the mismatch happens and it won’t look seamless on the sphere. Examples of
seams problems are shown below.
In addition to making sure that the data fills the entire frame, from 180° West
to 180° East, also make sure that the data fills the entire frame from 90°
South to 90° North. If there is missing data at the poles, fill in the area
with a solid color or a basic land/ocean background to ensure that the dataset
wraps properly around the sphere without stretching vertically.
A color scale can dramatically change the emphasis and message of a dataset.
Because of this, the Science On a Sphere Users Collaborative Network has had
many discussions on the color scales that are used for SOSx datasets. The goal
is to create datasets with well-chosen color scales that are meaningful,
intuitive, and scientifically accurate. Several conclusions are the result of
It can be confusing to users when the same color scheme and their associated
color bars are used for two completely unrelated datasets
The same color should not be used to represent more than one thing,
i.e. if ice is shaded white, then white should not also be used for
areas of missing data
Using rainbow-colored legends and color schemes is often confusing to the
audience and hard to parse. Instead, consider using shades of green to
represent phytoplankton, and blue and red gradations to represent temperature
anomalies, i.e. use “meaningful” colors
Avoid using full sphere backgrounds that are completely or pre-dominantly
white. The seams between projectors become more apparent when using solid
white/bright backgrounds. If using bright background colors, consider adding
some noise/texture to them. Same goes for PIPs, especially those displayed at
the seams between projectors
Single images are typically named for their resolution, such as
Image sequences are kept in folders that are named for their resolution,
and the images themselves should be named to sort in ascending order from
earliest to latest. This can either be done with a time stamp in the file name,
or a frame number in the file name with a sufficient number of leading zeros to
ensure time compatibility, shown in the examples below. If your data is
time-matched, the images should be named accordingly. See Filename
Mask examples in Establishing Time for Image
Videos should be named based on content and resolution, such as
hurricanes_2048.mp4. Do not use spaces and special characters in
In order for SOSx to display time and date for your image sequence dataset, you
need to be able to establish a Period, Start & End Time and a Filename Mask.
These are added in the Tour Builder when adding a new dataset. This is also
dependent on an indicative filename sequence.
In this “named by frame number” example, you would also enter File Sequence
Start and File Sequence Increment: File Sequence Start is 1 and File Sequence
Increment is 1. See Time Sequence in the Using Tour Builder
section for the interface in Tour Builder where these are entered.
Colorbars and legends can (and should) be used when applicable as they provide
context and units for the data. These should be standalone image files (.png or
.jpg) and not burned into the global images. 500 pixels is our standard size.
Never burn images into the data itself as warping can happen when wrapping
around a sphere.