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Polar Satellite Captures Fire Spread

Published 2 days ago
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The above animation of VIIRS polar satellite imagery over interior Alaska south of the Brooks Range from the afternoon of 15 Jul 2016, shows how quickly fires can spread in less then 4 hours. The three images used for this animation were modified versions of the NaturalColor RGB, where the 2.3 um channel was assigned to the red color component (rather than 1.6 um), 0.86 um to green, and 0.64 um to blue. The 2.3 um has similar ice and snow absorption characteristics as the 1.6 um, but with more sensitivity to hot spots and fires. In this imagery the red pixels are the hottest and most active fires with bluish colored smoke blown eastward by strong west winds. 

GINA’s BDL in Mobile Mapping Apps

Published 5 days ago

We recently had a question about getting GINA’s Best Data Layer (BDL) into BackCountry Navigator TOPO GPS a navigation and topographic map viewing application for Android smart phones and tablets.  Since it is easy to do, and might be of interest to the wider community, here is how to do it:

First, hit the “Map Layers” button, then the “MORE MAP SOURCES”, followed by the “CUSTOM MAP SOURCE”, and finally the “NEW CUSTOM MAP SOURCE” menu items.

This could give you a dialog like this:

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Fill it out like above, hit “SAVE”, and it should now show up in the “Map Sources” list, and should be usable just like any other map source in Backcountry Navigator, including using its tools for building an offline cache.

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More detailed instructions can be found on Backcountry Navigator’s help site.

Other mapping applications that allow custom map sources work similarly, and this process will work for any of GINA’s other web mapping tile sets.

Happy mapping!

-Jay

PS: The “Max Zoom” setting affects resolution of the data - larger zoom levels mean more detail, but that comes at the cost of space.  A value of 16 works out to be about 2.4 meters per pixel, 19 to be 1/3 of a meter per pixel.  

New elevation color-relief hill shade layers.Over the past few...

Published about 1 month ago



New elevation color-relief hill shade layers.

Over the past few weeks, fellow GINA GIS analyst Mitch Slife and myself have been busy in the GIS lab cooking up something special.  We have been working on creating a new set of shaded color-relief images. Inspired by an old post by Tim Sutton on linfiniti.com, we focused on a fully command line workflow for generating geospatial masterpieces without  restrictive obstacles like graphical user interfaces.  This fully command line approach will allow us to scale this new hill shading to a variety of other elevation datasets in our archives.

 We will be following this post up with links to the new datasets in our Web Mapping Services (WMS) and catalog system so those interested can start using these hill shades in their day-to-day GIS visualization activities. 

~Andrew Herbst

A plane creates a neat artifact in statewide orthomosaic map.The...

Published about 1 month ago





A plane creates a neat artifact in statewide orthomosaic map.

The 2010-2015 statewide orthomosaic map was created using satellite imagery, SPOT5 satellite specifically.  The SPOT5 satellite has two imagery sensors, 10m resolution multispectral sensor that provides color information and a higher 2.5m panchromatic sensor that provides higher resolution detail in greyscale.  These two sets of sensor data are combined to create the SDMI orthomosaic map product.  Think of the two sensors as two different cameras taking pictures from the satellite in space.  The images are not captured close in time but not exactly the same time.  This creates a neat effect that can be seen in fast moving objects like airplanes.

The images here show the effect of having a plane being captured first by the high resolution, 2.5m, panchromatic sensor (greyscale) and then being captured by the lower resolution multispectral (color) camera.  The plane has flown forward and the spacecraft has orbited farther down it’s earth orbit changing the look angle of the camera.

More details about the statewide orthomosaic map and the Alaska mapping efforts can be found at the following websites:

http://agc.dnr.alaska.gov/imagery.cfm

http://alaskamapped.org/ortho

Browse the SDMI ortho map imagery at:

http://browse.alaskamapped.org/orthos

-dayne

We have recently added USGS Historical topographic maps for the...

Published about 1 month ago
Solomon, near Nome, circa 1950


Solomon, near Nome, circa 1907


Chena Hotsprings Road, circa 1949 according to the map. This is a case where the map date is probibly wrong.


Chena Hotsprings Road, circa 1950


Chicken, circa 1957


Chicken, circa 1951


Chicken, circa 1899

We have recently added USGS Historical topographic maps for the State of Alaska to our EPSCoR Web Mapping Service (WMS) at http://ogc.gina.alaska.edu/epscor .  These maps provide an interesting look at how Alaska has changed over time.  Questions or comments?  Email us at support@gina.alaska.edu .
 -Jay

Kageet Point, Icy Bay, Alaska (Natural Color Pléiades Composite - 50cm acquisition 5/12/2016) | GeoNorth

Published about 1 month ago Kageet Point, Icy Bay, Alaska (Natural Color Pléiades Composite - 50cm acquisition 5/12/2016) | GeoNorth:

Today’s Image of the Day from from GeoNorth was selected from an Alaska based scene near of Kageet Point, Icy Bay Alaska.

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I’m guessing the GeoNorth folks noticed this image because this is over an area they are helping us do cloud patching of the Statewide Orthomosaic.  This is from our Batch 2 delivery of cloud patching.

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Happy mapping

-dayne