AURORAL FRIENDS
Live Data
Polar VIS (website)
A complete list of real-time data links is located in the Space Weather Resources section.
From Satellites: Polar VIS Images
By clicking on the Polar VIS live data link you will be able to access VIS images directly from the Polar VIS site. This will allow you access to archives of images for more in-depth research. When you click on the live data Polar VIS link, you will see the following page.
This shows the Current Image. The left menu bar of this page provides a wealth of additional images. The top 7 buttons will be especially useful. The seventh button, Previous Images, provides an archive of images from 1996. When you pick the year of interest (for example 2003), the next page groups the images by Day Of the Year (DOY)
The link 001_007 will provide the images from Jan. 1 to Jan. 7, and 092_098 provides images from April 2 to April 8.
Let's see what part of the page for 092_098 looks like.
This will take some explanation. Don't rely on the dates printed on the right! The correct dates for the images are imbedded in the file name. Examine the second file name as an example; 30920711_MAP.GIF + the first number (3) means the year (2003), the next three numbers (092) gives the day of the year as the 92nd day (April 2), the next four numbers (0711) tells the time of day in Universal Time. The MAP tells you there is a map of the globe superimposed on the image.
Now if you wanted to see if there was a strong aurora that extended into the northern United States on April 2, 2003. If you go to the VIS site and get the image for April 2, 2003 at 7:11 UT, you should see the image below.
Is this a nighttime or daytime view (above)? What part of the Earth is featured? (hint: the South Pole is on top) Click on the image above to get answers to these questions.
Notice that the image you just retrieved will not tell you about auroras at night over the United States. The VIS images are several minutes apart and the Polar space craft orbits the Earth once every 17 hours. The image you looked at was at 7:11 UT. You wouldn't expect the satellite to have images of North America for several hours. In fact, there are no images between 9:48 UT (30920948) and 19:25 UT (30921925). By 19:25UT the satellite is observing the South Pole and Antarctica. There won't always be missing data. However, the 17-hour orbit could mean that Polar wasn't observing North America for 8 or more hours that are very important to you. Another satellite, TIMED, can be used to provide images of auroras that Polar might not be able to.
- NASA Official: Dr. James Thieman
- Project Manager: Don Robinson-Boonstra
- Website Manager: Bryan Stephenson