The MODIS program consists of two satellites, Aqua and Terra, that pass around the Earth, covering the entire Earth at least once every 24hrs. As you zoom in on maps additional information is revealed. Each option provides a slightly different dataset or view. There is a drop down menu for the Current Fire Activity overlay that allows selection from MODIS and VIIRS, GOES Heat and GOES Detections, All Satellites, VIIRS 375m, VIIRS Progression, and Perimeters. However, a lot of smart people have worked on this and have developed algorithms to mitigate this known potential for error, so the data is still remarkably accurate.ĬalTopo’s Fire Activity overlay combines data from 4 main sources: three satellite platforms, MODIS, VIIRS, and GOES, and the National Interagency Fire Center. This can result in fire detection being perceived in a different place than it actually is at, show the wrong intensity, or just miss a spot because it's hidden by a steep mountain. For all of the satellites, the angle from which they are viewing the earth ranges from straight above to somewhat oblique (off to the side.)įor example, if the satellite passes straight over San Francisco, but is recording data from 150 miles to the east and west of its location, then data it is picking up from Lake Tahoe is at an oblique angle. Some satellites stay in the same place above the earth at all times (geostationary), while others orbit the earth continuously. Some things to keep in mind when looking at this satellite data: These features have been added over the years, unfortunately usually as a result of fire activity.īelow we’ll take a look at the different types of fire data available in CalTopo, and pluses and minuses are inherent in each. Introduction to CalTopo Fire Dataįire Activity is a checkbox in the Map Overlays section.ĬalTopo aggregates data from a large number of sources that provide insights for fire fighters, fire managers, and the general public. To say that again - the more often the data updates, the less reliable it is as to where that fire is at on the ground. The more "real time" that the data is, the less accurate it is.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |