6,526 reputation
1235
bio website
location Redlands, CA
age
visits member for 3 years, 6 months
seen 10 hours ago

I've been working with map projections and datum transformations for years, including in ArcView GIS, ArcInfo 7 and up, MapObjects, and ArcGIS.


13h
reviewed Close How to convert a National Bridge Inventory(NBI) ASCII file to a shapefile
1d
comment Why is POINT type layer not displayed correctly in my mapserver map?
I'm not familiar with QGIS, but similar questions have been asked before. Try searching with the terms, QGIS and projections. I wish I could help more.
1d
comment Convert coordinates
It's NAD83 (or later) State Plane New York Long Island, in US feet. EPSG:2263, NAD83; EPSG:2908, HARN; 6539, 2011; 3628, NSRS2007.
1d
comment Why is POINT type layer not displayed correctly in my mapserver map?
My guess is that the polygon data is using a projected coordinate reference system (CRS) while the point data is using a geographic CRS, aka latitude-longitude, but is defined or assumed to be in the same CRS as the polygon data. That fits with smaller lat-lon values showing up southwest of the other data.
Apr
13
comment Myanmar Datum 2000 information
I managed to track down the Survey Dept website, but it had no information. It did say that you have to have military approval to buy topo maps...that implies to me that this type of info is not going to be available.
Apr
13
comment LIDAR Dataset displaying 500,000 meters to the East of correct position
EPSG:2881 is in US feet, not meters, which matches the proj defn too. Does the cty layer have a defined crs?
Apr
8
reviewed Leave Open When is an address in a new subdivision available for mail delivery?
Apr
8
reviewed Close Issue with KML over Openlayers Basemap
Apr
7
comment Question about BNG coordinate systems
The FME/MapInfo one is OSGB 1936 to WGS 84 (1), defined by US military (DMA now NGA), EPSG:1195, roughly 21 m accuracy. The QGIS one is EPSG:1314, OSGB 1936 to WGS 84 (6), defined by UKOOA, around 2-4 m accuracy.
Apr
7
comment Question about BNG coordinate systems
The correct EPSG code is 27700.
Apr
5
comment map composer grid annotation in DMS format
@ndawson Thank you!
Apr
4
reviewed Leave Open List of Offensive Symbols/ Colours for Cartography
Apr
4
reviewed Leave Open How to set input parameters for geoprocessing task that uses Intersect tool?
Apr
4
reviewed Approve suggested edit on How to filter the graph on which I want to find the shortest path
Apr
4
revised Ogr2Ogr exported this boundary 90 degrees incorrectly
added 42 characters in body
Apr
4
revised How does Arc projecting data without spatial reference?
added explicit text that data is not reprojected when missing coordsys.
Apr
4
answered How does Arc projecting data without spatial reference?
Apr
4
comment map composer grid annotation in DMS format
Voted to leave open because possible duplicate just says functionality has been added, not how to do it.
Apr
4
reviewed Leave Open map composer grid annotation in DMS format
Apr
4
revised map composer grid annotation in DMS format
changed from almost all caps, slight rewording, added qgis tag.