This will be a very quick post today. We wanted to use some historical USGS quads for analysis. We had a ready source, used ArcGIS to georeference them to a grid, but then wanted something approaching a seamless product. Enter gdal. First step, create an image to put the mosaic into: gdal_merge -o usgs_merge.tif -createonly input1.tif input2.tif … Then mosaic into that. Since we have … Continue reading Historical USGS Quads
The disk that held the personal geodatabases of our contour datasets died a while back, but not before I loaded the contours into PostGIS and started serving them up. Our new intern is working on putting together some shapefiles layer groups in ArcGIS for map production, and asked for a missing one… . I don’t have it, but in principle can always extract it from … Continue reading Geometry Collections and Small Headaches
As we move away from a simple stack of PostGIS/GeoServer/GeoWebCache/Openlayers to wrapping a MapFish print service into the stack, it’s time to think more seriously about optimizing and stabilizing GeoServer. In preparation for this step, I’ve been setting up a series of VMWare ESX-hosted Debian Linux VMs to function as the cluster of geospatial services. Fortunately for me, there’s plenty of great advice in Andre … Continue reading GeoServer Optimization
I promised pics from our labeled parcels: https://smathermather.wordpress.com/2011/02/01/parcel-annotations-in-geoserver-with-some-maplex-help/ https://smathermather.wordpress.com/2011/02/01/parcel-annotations-in-geoserver-with-some-maplex-help-cont-1/ Continue reading Parcel Annotations in GeoServer (with some Maplex help) (cont. 2)
In one and two previous posts, I talked about McNab indices and what they mean and how to compute them. This is a short post just showing another screenshot of a McNab mesoscale. The previous image was from a stream valley running through the glaciated Allegheny Plateau. This image is a stream cut through the soft shale of the Lake Plain of the Eastern Basin … Continue reading Landscape Position and McNab Indices (cont.2)
See the previous post for an explanation, but here’s the SLD we used for parcel labeling. Now remember– we got those rotation values from Maplex, so this isn’t a pure use of SLDs, but boy is it a long one anyway: <?xml version=”1.0″ encoding=”ISO-8859-1″?> <StyledLayerDescriptor version=”1.0.0″ xmlns=”http://www.opengis.net/sld” xmlns:ogc=”http://www.opengis.net/ogc” xmlns:xlink=”http://www.w3.org/1999/xlink” xmlns:xsi=”http://www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=”http://www.opengis.net/sld http://schemas.opengis.net/sld/1.0.0/StyledLayerDescriptor.xsd”> <NamedLayer> <Name>Parcels Annotation</Name> <UserStyle> <Title>Parcels Annotation</Title> <Abstract>Symbolization for labelling of parcels</Abstract> <FeatureTypeStyle> <Rule> … Continue reading Parcel Annotations in GeoServer (with some Maplex help) (cont. 1)
smathermather: We have a guest blogger today– Ramon, a bright and hard-working intern I’ve had the pleasure of working with for over a year. If you’re looking for someone versed in Postgre/PostGIS/GeoServer/OpenLayers, Ramon’s been my rock as we’ve been building our internal system, doing everything from basic grunt work to esoteric trouble-shooting. I’m trying hard not to fall on my face now that he’s moved … Continue reading Parcel Annotations in GeoServer (with some Maplex help)
I typed that last one too quickly– too many typos, but my wife says I’m not supposed to revise blogs, but move on… . So, for clarity, let’s talk a little more about McNab indices. Field-derived McNab indices are a measure of average angle from the observer to the horizon (mesoscale landform index), or from the observer to another field person a set distance away, … Continue reading Landscape Position and McNab Indices (cont.)
Just a quick teaser post for our forestry/ecology readers out there. I have a methodology developed for calculating McNab indices that directly corresponds with the field technique (unlike, as far as I know, any previous GIS-based techniques– which are probably adequate proxies). What is a McNab index? Well there are two kinds, the minor landforms and mesoscale landforms that are field-measured topographic position or terrain … Continue reading Landscape Position and McNab Indices
Smathermather's Weblog 