Posts Tagged ‘usgs’

Review of Avenza’s PDF Maps app for iPhone and iPad

Tuesday, October 12th, 2010

openwith processing maptools

This app gets the job done: PDF Maps introduces a strongly played set of basic features and later versions promise to add more advanced features like layer visibility and feature attribute query. Professional cartographers can use the app to deliver custom cartography maps that leverage GPS to locate the map-reading customer with the magic blue dot. It’s certainly not an ArcPad, but it works on the iPad and you’ll find it fun to use (and the app price is right).

I quite enjoy Avenza’s new free PDF Maps iOS app, free and available now on the iTunes App Store for iPhone and iPad. I’ve been testing it for several months using both the beta and  final release versions. I’ve used the app in my neighborhood, on a cross country road trip, and we’ve been using it to ground truth maps at at my day job. I’ve created my own GeoPDFs and used those from USGS and Avenza.

Besides myself, I setup two non-cartographers with an iPad (3g  with gps) and several GeoPDFs depicting neighborhood-level street maps to field check in the Washington DC metro area. They were amazed at how easy it was to locate themselves on the map and make notes by dropping markers they bring back to the office for me to review. Because these particular maps include street labels, they don’t need to switch back and forth to Apple’s provided Google Maps app as they navigate.

The inaugural version is iOS only but the company has had requests for Android, Symbian, Blackberry and even Windows 7 Mobile. Expect an Android version next. Future iterations of the app may introduce a two-tiered, free-basic feature and pay advanced feature parellel versions, which seems reasonable to me. I’m also excited to see if a white-label version becomes available (much like the Flash SWF export out of Avenza’s MaPublisher plugin for Illustrator) that cartographers can use to brand the experience and pre-bundle their maps.

PDF Maps offers the following capabilities:
  • View and load your own custom cartography maps and view them with GPS location
  • Supports both Adobe/ESRI geospatial PDF maps and TerraGo/USGS GeoPDF® files.
  • Access and interact with saved maps without the need for a live network connection
  • Standard GSP app features: Plot way-points, enter attribute data and notes, measure distances and areas
  • Standard iOS interface: Quickly view, zoom and pan maps using gestures (pinch, drag and flick, double tap)
  • HD version for iPad same app as the basic version for iPhone, slightly reworked interface
  • Does not currently support waypoint export, a key feature
  • Does not currently support import of KML and GPX files

To create a GeoPDF, you’ll need ArcGIS 9.3.1+ to export from ArcMap with preserve coordinate system checked. Or use Avenza’s MaPublisher plugin for Illustrator (version 8.2+). You can also download thousands of GeoPDFs from USGS. Even though the USGS files use the TerraGo GeoPDF format specification (versus Adobe + ESRI’s), it will open and render in PDF Maps.app. Avenza also offers dozens of sample GeoPDFs linked from within the app to get you started (click Maps, then +, then From Avenza PDF Maps Library and browse the list).

Adding maps is as simple as dragging them to iTunes or attaching to an email (making it easy to send map updates to your field checker). Clicking on a PDF link on the iPhone or iPad now prompts to open in the app, as seen in the first screenshot above . Once opened in the PDF Maps app, it will take a few seconds to minutes to render, second screenshot above. Once open, several tools are available, the most important of which is simply the “locate me” triangle button on the map map view.

Even though it’s all about the PDF map you’re looking at, the app makes it convenient to open the same view in Maps.app to see Google’s version of reality for cross checking, especially using the satellite map tiles there. This is possible for both the current map view using the tools menu, and to open a specific waypoint marker after clicking it’s location field.

I’ve loaded PDFs with the app that are more than 10 mb of vectors and performance has been good. When the map first loads it will process and prepare several zoom levels of precached tiles. This will make panning and zooming faster during actual map use and is worth the wait.

During precache rendering, you can still use the map, but the parts that will still be loading will be fuzzy for a while. Very large maps (larger than 20 mb, or more than 2000 sq. inches) are slower to render in this version (hey, it’s a mobile phone). For larger areas, I’ve been splitting the exported map into separate files. When multiple maps loaded in, there is a Maps table of contents listing.

I found a couple continuing quirks with the app and one major missing feature. The app really needs to export the map’s waypoints as CSV, KML, and GPX as an email attachment. I wish repositioning an existing pin was easier. The hit areas on some buttons is small, making it hard to use in a moving car. Sometimes it’s nice to have multiple marker icon labels open, but sometimes that is odd. At any rate, there’s no way to close them all en mass.

Quick and dirty test GeoPDF files:
(using Natural Earth, US Census, and other draft data)

Note: Because of USGS website quirks, it is not possible to directly download a USGS GeoPDF onto your iPhone/iPad in the field. The website doesn’t render properly (something about IE and cookies), and the resulting download file is ZIP format rather than PDF. Not sure why, since the PDF should already be optimized for file size (there’s only a 1.5% file size savings between ZIP and PDF in the Washington D.C. West quad sheet).

Check out more screenshots:

You’ve seen one block, you’ve seen them all

Tuesday, July 6th, 2010

beach

Ever look close, I mean real close at the imagery you seen in Google Earth and other online map providers? You’ll notice most of it, in the United States at least, comes from the USGS or USDA Farm Service Agency. But have you noticed they sometimes doctor the imagery to remove clouds or other collection artifacts? Well, look at the above image again ;) Here’s the Gmaps view in Tybee Island, GA. Thanks Andrew and Geoff!

Volunteered Geographic Information Workshop Notes

Tuesday, February 9th, 2010

This conference, organized by the USGS, happened last month here in DC, thanks Martin! Special import for crises like Haiti.

Also check out: O’Reilly’s Rethinking Open Data: Lessons learned from the Open Data front lines. Read more »

Lots of online presentations and notes, some listed here:

The main site has full listing and notes from breakout sessions . . .

Adding new rivers and lakes to 10m Natural Earth in North America

Tuesday, January 19th, 2010

Tom and I have been busy adding 4 times the rivers and 3 times the lakes we had for North America. This adds in many “missing” hydro features that one might normally find on a 1:10,000,000 hydrologic reference map.

Why were they missing from the first version of Natural Earth? It’s hard to wade thru 1:1,000,000 features to figure which to add and an even tougher job to attribute them with the correct name and scale ranks. There’s another factor: these extra features are great if you’re making a watershed map, but can be a little noisy when used as a background layer in say a political reference map.

Cody Rice, now of the EPA but formerly of the Commission for Environmental Cooperation (CEC) send along an amazing link last week. The CEC is a joint agency between the United States, Canada, and Mexico. Specifically: USGS, Natural Resources Canada, INEGI-Mexico. Each country contributed base data for a 1:10,000,000 digital atlas. The data is available in many popular formats and is in the public domain. Better yet, it includes GIS data attributes like river name!

We’ve compared with our existing Natural Earth linework and identified which features were missing. For those we’re adding, we’ve adjusted the new linework a nudge here and there so it lines up with SRTM relief and our existing linework. We’ve also gone thru and created lake centerlines and applied scale ranks to all in three new steps (10, 11, and 12). We have some final polishing but will be releasing, along with some slight adjustments to the original data, by the end of January.

Do you have time to donate? Unlike ranks 0 to 9 (the original data), this new data will NOT come tapered. We’d like it to be and can show you how.

Know of a similar, attributed with name, 1:10,000,000 regional dataset we could adapt into Natural Earth to build out our coverage? Please let me know at nathaniel@kelsocartography.com.

Preview images below:

Red = new at rank 10. Blue = new at rank 11. Black = new at rank 12. Grey = old at ranks 0 to 9.

Click images to view larger sizes.

hydro_west_coast

hydro_mid_west

hydro_east

hydro_mexico

hydro_alaska

hydro_yukon

hydro_quebec

Google Massively Automates Tropical Deforestation Detection (HughStimson.org)

Friday, December 18th, 2009

[Editor's note: Perhaps Wired magazine's Google evil-meter just tipped a bit less negative? In all seriousness, this sounds like a great project!]

Republished from HughStimson.org. Dec. 11, 2009.

Land cover change analysis has been an active area of research in the remote sensing community for many years. The idea is to make computational protocols and algorithms that take a couple of digital images collected by satellites or airplanes, turn them into land­cover maps, layer them on top of each other, and pick out the places where the land cover type has changed. The best protocols are the most precise, the fastest, and which can chew on multiple images recorded under different conditions. One of the favorite applications of land cover change analysis has been deforestation detection. A particularly popular target for deforestation analysis is the tropical rain forests, which are being chain sawed down at rates which are almost as difficult to comprehend as it is to judge exactly how bad the effects of their removal will be on biological diversity, planetary ecosystem functioning and climate stability.

Google has now gotten itself into the environmental remote sensing game, but in a Google-esque way: massively, ubiquitously, computationally intensively, plausibly benignly, and with probable long-term financial benefits. They are now running a program to vacuum up satellite imagery and apply land cover change detection optomized for spotting deforestation, and for the time being targeted at the Amazon basin. The public doesn’t currently get access to the results, but presumably that access will be rolled out once Google et al are confident in the system. I have to hand it to Google: they are technically careful, but politically aggressive. Amazon deforestation is (or should still be) a very political topic.

Continue reading at HughStimson.org . . .

App: iTopoMap for iPhone

Thursday, April 2nd, 2009

[Editor’s note: Download free USGS topoquads and use the GPS and maps when you’re out hiking beyond cell reception and when Google Maps tiles don’t work (and don’t have good contour lines, creeks, or trails on them anyways). I’ve used the app and it works exactly as advertised. Thanks Martin!]

Republished in part from Martin’s posts at BackpackingLite.

Just downloaded and started using a new topo app for the iphone called iTopoMaps ($15) (web site). Looks like someone who backpacks and programs has gotten around to designing a topo map application. (There is another app called TopoPointUSA for $10 but I don’t like it as much.)

This app allows you to download and cache USGS topos on your phone freely downloadable through the phone in advance before your hike so that you can use the iPhone while in the wilderness, no need a 3G or cell phone signal. Turns the iPhone into probably the best mapping GPS with no fees to pay for maps.

I used this in Shenandoah today and it worked well. Still no route planning (track or GPX) functionality but apparently it’s coming. It does allow to create waypoints. This app may be what finally justifies my iPhone after 8 months of love/hate.

Feature list:

  • Full 1:24k USGS Quads that can be locally cached on your iPhone
  • Scrollable multi-zoom map interface (likeGoogleMaps!)
  • Full 50 states
  • Waypoints
  • Goto Waypoint – distance and bearing
  • Magnetic Declination Calculations
  • GNIS Database for looking up features and identifiying them on the map!

I think the app hits the USGS google topo map server and downloads the image pyramids there. But they are free and will likely remain free.

You acquire the topos by tapping the screen while connected to the internet. So it does require a signal initially while planning and also requires some advance planning. But I cached all of Shenandoah yesterday before leaving my house while connected to broadband without any problem ( I have about 12Gb of free space on my phone so that helps). Those quads are now stored on my phone and since I visit Shenandoah very frequemtly they will stay on my phone for my next trips. No memory cards to fiddle with, no extra fee to pay to TOPO or Delorme or Garmin. FREE USGS topo Maps.

Google Maps With A Topographic Overlay (Free Geog Tools)

Wednesday, July 23rd, 2008

free geo tools logo[Editor's note: An alternative to TopoZone.com. Their server can lag a bit.]

Reprinted from Free Geography Tools blog (posted there April 14, 2007).

In addition to the standard image overlays of Map, Satellite and Hybrid for Google Maps, the Active Trails website has an additional overlay button – Topo, for topographic maps. At lower zoom levels, the 1:100K scale USGS topo maps are visible, but if you zoom in close enough, the larger-scale 1:24K maps become visible. Comparing Map, Satellite and Topo overlays, there appears to be a good position match between the three. Active Trails also has placemarks for many kinds of outdoor trails across the country (hiking, biking, equestrian, etc.) entered by site users. You can also install a network link in Google Earth that will let you view the trails there, similar in nature to the new Google Earth layer from Trimble.

Addendum: Fixed the Active Trails links (sorry about that). In the comments, MH points out the ACME Mapper 2.0 site, which is a better choice. It displays black-and-white USGS aerial photos, and also lets you print out a copy of the on-screen map with the push of a button.