Satellite Imagery Site Ratings
...a part of the International Weather Satellite Images.
I plan in the future to have ratings in stars(0-5) for each group
of satellite images to help people who are overwhelmed by the
number of images. I have started work on the ratings system, but
it has been postponed indefinitely since I have decided that
descriptions would be more useful. These ratings are a few
years out of date (I think they are from sometime in 1996).
The Ratings
About the Ratings
When I rate the image groups, I think about the following
questions and guidelines for each category:
- Usability (0 to 20)
- Is it easy to see what is occuring in the image? Are there
map lines to help? Does having only strong clouds only appear
interfere with the image severely? A raw image is worth 5
points. Be careful not to account for resolution unless very low
resolution interferes with usability.
- Regions (0 to 20)
- Is there a good selection of regions to choose from, or must
one retrieve the entire image to see one part? Are there high
resolution *and* low resolution versions? Are different areas
available? Are there zoomed images of specific regions? Are
there floater images? An image covering only one, well selected
area merits 5 points.
- Top Resolution (0 to 15)
- Does the highest resolution available show good detail? Does
being low resolution hurt the image quality, especially in a
Mercator Projection?
- Image Types (0 to 15)
- Are there many types of images are available -- Visible,
Infrared (how many channels?), Water Vapor. Are both normal and
enhanced infrared available?
Point guidelines:
- Only visible is 0 points.
- Only infrared is 3 points.
- Visible and infrared is 6 points.
- 3 channels is 9 points.
- 5 channels is 12 points.
- Having enhanced infrared and normal IR is worth 3 points
extra, while having only enhanced is worth 2 extra.
- Visual Presentation (0 to 10)
- Does the image look nice? An image good enough to appear on
television should generally get above 5 points. Poorly drawn lettering
or other such problems hurt in this category. Be careful not to
account for usability.
- Updating (-10 to 10)
- Are the images up to date? Are they updated frequently?
Guideline: updating every 3 hours with 1 hour delay is worth 0 points.
- Archiving (0 to 20)
- The type of archive is on the following scale:
- No archive of past images is 0 points.
- H-1, H-2, ... H-6 archive is 5 points.
- Last few days by time is 12 points.
- All of the site's history is 20 points.
How easy is the archive to access? - This can modify the score
- Status Information (-5 to 5)
- If one cannot determine the time that the image was taken in
any way, rating is -5. Otherwise, on a 0-5 scale, is the status
information given on the image, in the filename, or elsewhere
good. Is it easy to understand? Is it easily accessable?
- Access (-5 to 5)
- Are the images stored in a good file format? Are they easy
to access at the site (no special filename for the latest image
hurts)? Is the site quick and reliable?
Total to Stars Conversion (tentative)
| Total | Stars
|
| 90+ | 
|
| 65-89 |
|
| 47-64 |
|
| 27-46 |
|
| -26 |
|
(Back to
International Weather Satellite Images
David Baron)
LDB,
dbaron@dbaron.org