A GLOBE Guide to MODIS Rapid Response

The NASA Earth Observing System Data and Information System (EOSDIS) Website offers several options to view, monitor, and assess MODIS imagery! In many cases, images are available within a few hours after they are made, so you can get a jump start on comparing your observation to the satellite. We will highlight those that are simple to use.

MODIS scans back and forth as it takes an image. The edges of the image are distorted. The Real-Time images are displayed as they are scanned by MODIS, without correction for geometric distortion. Since the observed pixels at the edge of the swath are bigger than they are in the center, they appear to be scrunched into a too-small grid box when displayed "as-is" in the Real-Time imagery. The distortion is more obvious in the higher resolution images (i.e., 250 m pixels). The images in the Gallery have been corrected for distortion.

For more details see Near Real-Time vs Science Quality.

• Worldview: Provides a "live" look at the entire Earth. Imagery is available from May 2012 to current and can be seen as soon as three hours after being scanned by MODIS. For simple navigation tips visit the GLOBE Worldview Tutorial.
  
  
• MODIS Near Real Time (Orbit Swath) Images:
  
  If you know the Universal Time (UTC) of the satellite overpass (such as from your S'COOL overpass schedule):
  1. Click on the MODIS Near Real Time (Orbit Swath) Images link. Images posted for today will be shown. You can also choose other dates by clicking on the calendar.
     Note: Terra appears first on this page, with Aqua below.
  2. You can find imagery corresponding to your observations using the Universal Time (UTC) stamp on the MODIS images (posted at 5 minute intervals) and the S'COOL overpass schedule.
  3. Click on the thumbnail to see the image in multiple resolutions and band combinations.
  
  If you do not know the UTC:
  
  1. Click on either the Terra or Aqua "Orbit Tracks" hyperlink at the top of each box containing the satellite images.
  2. Find the area you want to see on the map.
     • On the Terra Orbit Track map, the lines that run from the top right to the lower left show where it was during the day when MODIS can take true-color images. The lines running top left to lower right show Terra's night-time orbit tracks. Since only day-time images are posted on the site, find the day time line that runs closest to the area you want to see.
       Note the time stamp to the north of the area you want to see. The time stamps mark the northern and southern edges of the images.
     • On the Aqua Orbit Track map, locate the nearest line running from the bottom right to the top left. This traces Aqua's daytime orbit.
       Note the time to the south of the area you want to see.
  3. Close the orbit map, and scroll to the right time - remembering that Terra appears first on the page, followed by Aqua.
  4. Click on the thumbnail to see the image in multiple resolutions and band combinations.
• Gallery: The Gallery contains images (corrected for distortion) of important events or that the MODIS team has selected to highlight.
  
  To find MODIS images in the Gallery:
  1. The most recent images appear on the page (to confirm click the "Display most recent images" hyperlink at the top of the page), OR
  2. Enter the date and/or keyword (name of the country or state) in the search boxes.