NYPL has a new toy tool for rectifying digitized historic maps from their collection called the NYPL Map Rectifier.
After creating an account, browse through the various maps and collections, choose a map to rectify, clip or mask the image, and finally export out to either a KML (for Google Earth) or a WMS base URL for use in a GIS software. Some maps have the option to export into either PNG or TIF formats as well.
There is also a vectorize option for a few of the rectified maps (I didn’t see this option on most maps, I’m guessing because it’s still in beta). For these, the vector layers can be downloaded in several formats including shapefile.
NYPL has also created a site called Relief Map Warper and has uploaded maps for Haiti which after georeferencing, the maps will become available in Open Street Map for tracing, and also made available for use on the ground by relief workers. I highly recommend joining and helping out if you can.
A spatial join is a method for combining information between GIS layers. Performing a spatial join results in the attribute information from one layer being combined with the attribute table of another layer based on their relative location. This then makes further analysis possible.
This two hour workshop aims to demonstrate the powerful spatial analysis capabilities of spatial joins and how they can be used to examine the spatial relationships between different data layers. Objectives of the workshop include:
Learning the purpose and capabilities of spatial joins
Correctly setting up spatial joins based on cardinality and feature type.
Learning to solve problems with spatial joins.
The lecture will be followed by a hands-on exercise. An introductory level knowledge of ArcMap is required to attend.
Thought we would mention a few new spatial datasets in our collection. We now have updated Transportation layers for New York city including routes and lines for subways, buses, freight and commuter rail as well as updated truck routes and zones.