Archive for June, 2015

The National Geodetic Survey Data Explorer and Citizen Science

June 29, 2015 1 comment

The National Geodetic Survey (NGS) Data Explorer is a web mapping application, launched by the Survey in 2012, allowing users to view geodetic control data across the USA and its territories.  To use, zoom in on the map on a location of interest, and select “plot marks”.  You will see all of the control marks in that vicinity, including CORS, GPS sites, horizonal control markers, and vertical control markers.  Furthermore, the NGS datasheet documentation for each control mark is accessible from the same mapping interface, including the latitude, longitude, elevation, position source, complete description of the physical marker, the history of the marker, the condition of the marker, and other information.

The mapping site was launched in 2012 and has seen improvements since then.  I found it easy to use, and very useful. The only thing I could not find that would be extremely helpful is the ability to export from the map and data set to a variety of formats–a geodatabase would be nice, or at the very least, a spreadsheet.  I also could not find how I could “select” points that I was interested in, aside from clicking on each one on the map.

Our book discusses the impact of citizen science efforts on geospatial data.  On this note, the NGS also runs a “GPS on Bench Marks” effort, a citizen science program for finding and reporting on the conditions of NGS benchmarks.  By providing GPS on bench marks today, people can help NGS improve the next hybrid geoid model, increasing access to the North American Vertical Datum of 1988, and enabling conversions to the new vertical datum in 2022.  Participating could also help the local surveying community know about nearby marks by improving scaled horizontal positions and updating the mark condition or description by submitting a mark recovery.  A web map in ArcGIS Online is here.

If you are interested in other activities and services from the National Geodetic Survey, see the recent excellent summary in The American Surveyor.  This includes guidelines for using post-processing GPS technology to establish accurate ellipsoid heights and orthometric heights, the new North American Vertical Datum that will be released in 2022, and updates on the GEOCON datum transformation tools.

National Geodetic Survey Data Explorer

National Geodetic Survey Data Explorer.

Georeferencer Project: Crowdsourcing location data for historic maps

June 22, 2015 1 comment

In 2011 the British Library set up the Georeferencer project to crowdsource the georeferencing of its collections of scanned historic maps. By adding georeference (coordinate) data to the old maps, they can be viewed alongside modern maps via the Old Maps Online data portal and the catalog of georeferenced maps.

Georeferencer Project

Georeferencer Project

Using illustrations extracted from digital books and public domain images posted on Flickr, many of the maps were identified and geo-tagged by a team of volunteers as part of a Maps Tag-a-thon event that ran from Nov 2014 to January this year. Among the collections of maps released so far are the Ordnance Surveyors’ Drawings (one inch to a mile maps for England and Wales 1780 – 1840) and the Amercian Civil War collection.

American Civil War Maps

American Civil War Maps

To date, over 8000 maps have been successfully georeferenced and quality checked by a panel of reviewers.


Your Location History: Legitimate Concerns about Privacy or Not a Problem?

June 14, 2015 2 comments

If you are a frequent reader of this blog or of technology related news feeds, it should come as no surprise that location has rapidly become one of the basic means of communicating, marketing, and crowdsourcing in our modern world.  Is the data that you are inadvertently communicating through your mobile device that powers many web mapping services via crowdsourcing making our world more efficient and sustainable?  Take the common example of your position moving through traffic, communicated from location information on your smartphone, calculated using the miracle of web mapping technology into speed, and combined with others to create real-time information about which routes are currently running sluggishly and which are running quickly in your metropolitan area.  Most would argue that yes, this does make people’s commutes more efficient by saving time. Moreover, it saves fuel through a multiplier effect if even a fraction of the vast number of people commuting at any given time around the world adjust their behavior by avoiding traffic snarls and idling their engines.

Is that same data compromising your personal privacy? Most would probably argue that while each of us gives up a bit of location privacy for these real time traffic feeds, the resulting public benefit far outweighs the costs. An analogy from the 1990s might be the personal information that most of us shared with grocery businesses in order to obtain a ‘discount card’ from our local food store.

The “tipping point” of concern for some on the personal privacy seems to be where location services allow you, and by extension, depending on the application, anyone, to see your own personal location and movements over time.  For example, examine this page describing how location reporting from an iPhone and iPad allows Google to store a history of your location devices where you are logged into your Google account and have enabled location history, or related articles about Android devices.  There are ways to override this location history, but it takes just that–overriding the defaults, and–will this override be possible in the future?

I checked, and I don’t have any location history, at least in Google.  But would it matter if I did?  As a person who loves and works with maps on a daily basis, part of me was a little disappointed, actually, that I couldn’t see what I thought might be a fascinating set of maps showing some of my field work over the past few months, which included some brisk but pleasant walks along the lakefront in Chicago during the AAG annual meeting and a trek through a wetland in Wisconsin afterwards.

I frequently work with secondary and university students, and in my conversations with them, I’ve noticed that the younger generation generally doesn’t see a problem with sharing anything in the digital world, whether it is their location, photos, videos, links, whatever.  So, is it just my generation that is a wee bit nervous about the potential harm that could result from personal data being mined?  Should other generations be concerned?  Our goal in this blog and in our book is to raise awareness of the power and utility of geospatial information, and also to critically assess its quality,use, and implications.

You are here!  Reflections on location privacy.

You are here! And who else knows you are here? Reflections on location privacy.

ENERGIC OD – Virtual Hubs for Open Data

June 8, 2015 1 comment

Over the last three years we’ve written about a few of the problems associated with some data portals, which although well-intentioned, haven’t always provided the level of access to geospatial information that they promised. Interoperability issues, interface design and a lack of on-going support have contributed to many such initiatives failing to deliver. With the experience gained from those earlier efforts and perhaps the benefit of hind-sight, new initiatives are being developed to provide better access to the plethora of public domain and open data geospatial information that is available online.

Among those new initiatives is the ENERGIC OD project (European NEtwork for Redistributing Geospatial Information to user Communities – Open Data). Launched at the end of 2014, the project aims to address some of the problems that have resulted from the evolution of disparate and heterogeneous GI systems and technologies by providing what are referred to as Virtual Hubs. These hubs will provide a single point of access to geospatial datasets, including access to INSPIRE compliant systems and Copernicus satellite and sensor data (Copernicus was previously known as GMES). The brokering framework at the centre of the solution will allow the hubs to connect to a wide range of European data sources making it easier for end users, public authorities and private organisations, and developers alike to access the data without having to resolve the interoperability and standardisation issues themselves.

ENERGIS - OD - Virtual Hubs

ENERGIS  OD – Virtual Hubs

The ENERGIC OD project will run for three years and deploy five national virtual hubs in France, Germany, Italy, Poland and Spain.