April 16, 2012 5 comments

Welcome to the Spatial Reserves blog.

The GIS Guide to Public Domain Data was written to provide GIS practitioners and instructors with the essential skills to find, acquire, format, and analyze public domain spatial data. Some of the themes discussed in the book include open data access and spatial law, the importance of metadata, the fee vs. free debate, data and national security, the efficacy of spatial data infrastructures, the impact of cloud computing and the emergence of the GIS-as-a-Service (GaaS) business model. Recent technological innovations have radically altered how both data users and data providers work with spatial information to help address a diverse range of social, economic and environmental issues.

This blog was established to follow up on some of these themes, promote a discussion of the issues raised, and host a copy of the exercises that accompany the book.  This story map provides a brief description of the exercises.



A Review of the Geoportal

March 19, 2018 Leave a comment

The GEOSS is a portal run by the European Space Agency (ESA) Group and the Group on Earth Observations (GEO) that provides one way to access earth observation data from around the world.   The site focuses on satellite imagery–Sentinel and Landsat data.  One helpful feature about the site is the ability to send search results to social media or via email.  A list of Popular Searches is a good place to start with the site.  The site is definitely worth investigating as it features a wealth of data.  I found myself wishing that there were more predefined searches listed there (currently 4).  The site also offers a login option and the ability to save your “workspace” which is an intriguing idea; using this feature, you could come back to the site and continue searching and downloading with the knowledge of what you have done previously.  There are different formats available, although at many points in my work with the site, I was confused as to how to proceed, or what format my file would be in, and if I was truly downloading the extent shown in the interface.


Interface for the Geoportal.

Like other portals, this one allows search terms, but without knowing what is there, the user is left with some confusion knowing what search terms to use.  I found myself really wanting a tutorial and a list of data sets I could browse through.  Searching is good but the users also need to know what the possibilities are.  I am intrigued by the data offerings on the site but had trouble navigating and discovering resources; I frequently encountered this message below and even had trouble drawing the bounding box for my desired search area.


Given the data holdings that are available via this portal, I think it is worth investigating further.  The about page on Geoportal lists enhancements to the site that are continually being made, and the mission of the page states that one goal is to make the site intuitive and easy to use.  I therefore have high hopes that it will be moving in this direction.  Give it a try!

Reflections on the Effective Use of Geospatial Big Data article

Glyn Arthur, in a thought provoking article in GIM International, entitled “Effective Use of Geospatial Big Data“, raises several issues that have been running through the Spatial Reserves blog.  The first is to point out that the “heart of any geospatial analysis system is increasingly becoming the server.” Glyn, a GIS professional with over 25 years experience, then dives into one of the chief challenges that this environment brings, namely, to deal with the increasing quantity and variety of data that the world produces. Of particular importance is emerging sensor platforms which must be incorporated into future GIS applications. The second point is the need to embrace, and not avoid, the world of big data and its benefits–but also recognize the challenges it brings. The third point is to carefully consider the true costs of the data server and decision making solution when making a purchasing decision.

Frankly, I found the “don’t beat around the bush” theme of Glyn’s article refreshing. This is evident in such statements as, “for mission-critical systems, purposely designed software is required, tested in the most demanding environments. Try doing it cheaper and you only end up wasting money.”  Glyn also points out that the “maps gone digital” attitude “disables.” I think what Glyn means by this is that systems built around the view that GIS is just a digital means of doing what we used to do with paper maps will be unable to meet the needs of organizations in the future (or dare I say, even today). Server systems must move away from the “extract-transform-load” paradigm to meet the high speed and large data demands of users.  Indeed, in this blog we have praised those portals that allow for direct streaming into GIS packages from their sites, such as here in Utah and here in North Dakota.  The article also digs into the nuts-and-bolts of how to decide on what solution should be purchased–considering support, training, backwards compatibility, and the needs of the user and developer community. Glyn points out something that might not set well with some, but I think is relevant and needs to be grappled with by the GIS community, which is this:  A weakness of Open Source software is its sometimes lack of training from people with relevant qualifications and who have a direct relationship with the original coding team, particularly when lives and property are at stake.

Glyn cites some examples from work at Luciad with big data users such as NATO, EUROCONTROL, Oracle, and Engie Ineo. Geospatial server solutions should be able to connect to a multitude of geographic data formats. The solutions must be able to publish data with a few clicks. Their data must be able to be accessed and represented in any coordinate system, especially with temporal and 3D data that includes ground elevation data and moving objects.


Glyn Arthur’s article about effective use of geospatial big data is well-written and thought-provoking.

Categories: Public Domain Data Tags: ,

The Coastal Atlas from the Maryland Department of Natural Resources

February 5, 2018 Leave a comment

The Maryland Coastal Atlas serves up ocean use and resource data, coastal hazard and shoreline data, and near-shore and estuarine data.  The purpose of the atlas is to make coastal related geospatial datasets available to agencies, researchers, and the general public for viewing and for performing basic overlays.  Tools are being added to make the atlas more versatile for users to do analysis and to help simplify or select data important for different users’ needs. The list of layers is extensive; at least 100 items are included.  But equally impressive is its ability to add dozens more layers from the MDiMapD database on such themes as agriculture, housing, demographics, hydrology, and much more.

The Atlas uses the Esri Web App Builder for its interactive map capabilities.  One of my favorite things about the atlas is the user’s ability to add data to the web interface from ArcGIS Online, a URL, or a file of the user’s own creation.  The site features unexpected helpful touches such as palette of drawing tools that makes the atlas a rich teaching tool, and transects that can be drawn in the map to analyze such things as erosion rates.

A few enhancements on the site could be done to make it more useful, such as an expansion of the fairly limited query tool and an explanation of how it can be used.  I was puzzled how to close the transect results once I had created one, but this and other user interface questions were small; overall, the interface was intuitive.  The Maryland Coastal Atlas provides an excellent addition to the other portals we have written about in this region, such as the Maryland iMap Data Catalog We wrote about the state of Maryland’s GIS portal in the past, and the selected other data portals for the Chesapeake Bay.

The atlas uses the map services available from the Maryland GIS Portal and the iMap Open Data Catalog that we reviewed above.  To obtain the data, go to the Maryland Data Catalog to download the data or get the API to use in an online mapping application.  All of the Maryland Coastal Hazard datasets on the atlas are available through the data catalog but not all are downloadable.  Here is an example of a dataset on the atlas shown in the iMap Data Catalog with the Download and API function available on the listing.  Every layer is a REST service hosted by Maryland iMap, managed by the Geographical Information Office (GIO) and the state IT group (DOIT).


The Coastal Atlas from the Maryland Department of Natural Resources.

Privacy concerns from fitness maps and apps

January 31, 2018 Leave a comment

We frequently write about the need to teach about and be aware of location privacy with the rapid advancement and web-enablement of GIS.  Thus it wasn’t a surprise when recent concerns arose over an amazing map from Strava Labs.  Maps generated from GPS-enabled fitness devices and other recreational uses of GPS such as GPS Drawing, as well as those from the fitness tracker market such as Fitbit and Garmin, have for several years been sharable and viewable.  Strava has been one of the leaders in helping people stay motivated to meet their fitness goals by providing tools such as apps and maps.  But perhaps the Strava map attracted more attention than others because it contains an amazing “over 1 billion activities and 13 trillion data points”, or perhaps because the map is so responsive and contains some stunning cartography that the web map user can customize.

Whatever the reason, as reported in USA TodayPopular MechanicsWired, and elsewhere, location privacy concerns have arisen recently over the new Strava map.  Specifically, “Security experts over the weekend questioned whether the user-generated map could not only show the locations of military bases, but specific routes most heavily traveled as military personnel unintentionally shared their jogging paths and other routes.”  Some of the posts have reported that it may even be possible to scrape the data to discover the person behind each of the tracks, and the Strava CEO has responded to these and other concerns.  Any GIS user knows that much can be discovered through mapped layers and satellite imagery these days, shedding new light on what is really “secret” in our 21st Century world, but maps aimed at the recreational user are bringing these discussions to the general public.  The particular concern with the Strava data is not so much just the location information, but the temporal data tied to the location, and potential identification of individuals.

Much of it comes down to what we have been saying in this blog–understand the defaults for whatever you are doing in GIS, whether it is the projection of your geospatial data or the location-based app on your phone.  Ask yourself, “What is the default–is my data public by default? Is my projection Web Mercator by default?  Can I override the default, and if so, how?  What is the best way to represent this spatial information?  Do I need to share this information?  If I need to share the information, how should I do it?”  and then act accordingly.   For more on this topic, I encourage you to read some of our short essays, such as Why Does a Calculator App need to know my location?, Making the Most of Our Personal Location Dataposting cat pictures and The Invasion of the Data Snatchers.


A section of the Strava heat map, showing the results of people who have recorded and shared their fitness walks and runs.  As one might expect, city park and a high school track stand out as places where more people conduct these activities.  As with other maps showing locations where people are now or where they have been, location privacy concerns have been raised. 

Planet’s Imagery Now Viewable by the Public

January 29, 2018 2 comments

Back in 2014, we wrote about inexpensive and the miniaturization of remote sensing, as exemplified in Planet Labs then-new small satellites.  A year later, we wrote about the company’s (now called “Planet”) Open Region initiative with the United Nation to share imagery under a Creative Commons license.  As described in this National Geographic post, Planet has now created a web mapping tool that allows users to examine two million images, updated monthly.  The tool, called Planet Explorer Beta, contains images dating back to 2016, at anywhere from 3 to 40 meters.  My favorite feature so far on the Explorer Beta is the ability to drag-and-drop two images to create a swipe map, to compare changes over time for any given area.  If you create an account and log in, you can explore daily, rather than just monthly, imagery.  Whether logged in or not, the tool is an excellent and amazing resource for teaching and research.  It could also serve as a great way to introduce students and faculty to imagery and encourage them to go further and deeper with remote sensing.

As most of the readers of this blog are work in the field of GIS, they will want to know how to use this imagery in a GIS.  The viewer described above is just that–a viewer.  You can only view the images online.  To actually access the data for use in your GIS or remote sensing work, begin with Planet’s Documentation.  As Planet is a professional satellite image company, it comes as no surprise that users have a multitude of options from which to choose–bands, date and time, cloud cover, sun elevation and azimuth, rectification, data format, and much more.  The imagery is available via a Planet Explorer interface and a Data API, which requires installing a Python client.


Comparing imagery from two time periods in Colorado, USA, using Planet’s Planet Explorer Beta.

New working lists of US Federal and State GIS portals

January 15, 2018 Leave a comment

Joseph Elfelt of MappingSupport.com has compiled a very helpful working list of addresses for over 40 federal ArcGIS servers with open MapServer and ImageServer data:


And a list of over 50 state server addresses:


The lists also contain some key caveats and tips for finding local GIS data as well.  Joseph is open to the community contacting him with additional federal or state servers to add them; his contact information is at the top of the lists.  That these already excellent resources will continue to be updated is very good news.


A section of the very helpful federal and state lists of servers with open MapServer or ImageServer data, compiled by Joseph Elfelt.