[talk-ph] Does WMS/Landsat have an offset?

[Ed Garcia]

Related my earlier reply post on coastlines, here is an example showing that
the landsat image is probably offset or "not calibrated"?

here is a screen capture of JOSM showing Aslom Island south of Mindoro:

http://www.waypoints.ph/images/aslomisland.jpg

The blue trace is what OSM/Mapnik is currently showing as Aslom Island
(quite a big error),  And, the green raster image is the landsat image
showing Aslom Island.  Now, the yellow trace is an actual GPS track on a
boat that was actually made to go around the island with its outrigger
(katig) just about 5 meters from the land edge to trace the shape of the
island.  The GPS has the 12 satellites in view (which means very very low
position error).

As can be seen, the offset is about 50 meters between the landsat image and
the GPS tracks.  This is about the same offset observed when we tracked the
mangrove river in Sariaya that I mentioned in my earlier post.

Does this indicate that the landsat image is generally offset or not
calibrated?

:>) ed

-- 
website administrator:
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