Spent the lunch hour here listening to a gentleman from Trimble discuss GPS, GPS myths etc… Some Common GPS myths:
WAAS will work everywhere
GPS will work everywhere
All GPS receivers are the same
You can use a rec. GPS for GIS data collection
US coast guard beacons are coastal
Selective Availability is still on or will be on again
You can get an accurate position with less than 4 satellites
Other people can track you if your GPS is on
All basedata is accurate
Aerial or satellite imagery will replace the need for GPS
Datums are not important when collecting GPS
WGS84 datum is the same as NAD83
Vert accuracy is the same as horizontal accuracy
See also http://www.trimble.com/gps/index.shtml
Archives for June 20, 2007
ArcGIS Image Server – Author, Serve, Use…
Random notes about ArcGIS Image Server – Released with ArcGIS 9.2 late last year. Recall, imagery is a natural background for many GIS apps. Useful for direct interpretation, statistics and analysis, used for vectorization (80% of vector data collected using imagery backdrop), data verification after GIS analysis. Diff. apps have diff demands on their imagery – time, quality, sun angle, etc…
Why Image Server??
Use of imagery growing exponentially
Available from many sources (aerial cameras, scanned maps, satellites)
Depth of imagery increasing, more bands of imagery, higher resolution, overlap in imagery (same image from multiple dates or diff. angles)
Imagery is often available but simply not accessible (obviously Google Earth has addressed this)
Fast access to imagery and metadata
Much more! See ArcGIS Image Server – Author, Serve, Use… Random Notes from the ESRI UC for more on this
Developing Web2.0 flash mapping apps with ArcWeb Services
Some random notes from the session on AWX 2 — Recall recently ArcWeb explorer 2 beta 1 released last week – See arcwebservices.com labs
ArcWeb Services AWX2 is built on Adobe Flex 2
2 APIs – javascript and Flex 2 ActrionScript API
Simple authoring where anyone with a notepad should be able to author an ArcMap web service (Source: AWX dev team)
New Features in AWX2
– more map types… tiled streets (ArcGIS online), topo, shaded relief. Streets, aerial and hybrid always been there
– support for 13 diff projections (repro on the fly)
– create your own widgets (think Apple)
– using Flex API the map can be completely customized (via style sheets)
See Developing Web2.0 flash mapping apps with ArcWeb Services – Random Notes from the ESRI UC for more on this topic