Frequent commenter Boyd Ostroff, who keeps cranking out amazing Garmin-compatible maps, has just published a LIDAR-based map of a portion of southern New Jersey. I’m hoping we’ll see more of these for other areas, as the elevation detail is amazing.

I’m putting this under the handheld category but want readers to be aware that such maps should work fine on a nuvi. Boyd was kind enough to answer a couple of quick questions I posed, giving our readers some insights into LIDAR-based cartography:

Is the LIDAR elevation data more accurate?

See: http://stephencreek.com/gpstl/elevation.png

I think the LIDAR elevation data is highly accurate. Look at this example where the original full resolution data is shown at 24k scale on the left. On the right you see my conversion to polygons. While I could come very close to the original, and it works well in Basecamp, the gps devices just choke when the polygon count gets too high.

The current version shows approximate elevations when you mouse over the map, but they aren’t very accurate. For the next version, I’ve come up with a system of very accurate data for every polygon on the map. The spreadsheet below the map shows the data available for every polygon, and the map above shows average elevation. On the actual map, I won’t do this because it’s too cluttered, but when you mouse across or click, it will be displayed. I’m thinking to only display the average elevation… or do you think there would be value to also showing the minimum, maximum and slope?

Why did you choose color gradation over contour lines?

Well, for one thing, I’ve already used the same LIDAR data to generate the contour lines on my recent NJ 2012 map

see: http://stephencreek.com/gpstl/PinesLE_vs_NJ2012.png

Aside from that, the Pines LE map really serves a different purpose. Compare the two in that image; right away you get a feeling for the terrain. And it also starts you thinking about what created it – you can see how the streams etched their way into the landscape, and imagine how water once covered the low elevations.

You need to know a bit about the area I have mapped; the full range of elevations goes from sea level to only 74 meters. So I show the full range of colors through this small range. That exaggerates the terrain quite a bit – you might not even notice the things that looks like “mountains” here while driving around. Ed Campbell, a member of a local forum (njpinebarrens.com) summed it up very nicely: “I know the contrast is way up but the topography has my imagination in overdrive. I was half blind before. I have lots of geology questions.”

Look at this comparison with Garmin’s 24k topo. It has shaded terrain but it’s barely perceptible here, because the range of elevations isn’t enough to register on a map that also contains 3000 foot mountains. Of course, that also forces this to be a regional map with nothing higher than 74 meters. BTW – the gold triangle you see in this image is McGuire Air Force Base.

see: http://stephencreek.com/gpstl/boyd_vs_garmin.png

Aside from creating this particular map, one of my goals was to convert raster imagery to Garmin’s vector format on a large scale. The map covers about 5,000 square miles (87 quads) at 24k resolution (arguably better)…I don’t recall seeing a comparable project before. And I also wanted it to perform well on the gps through a wide range of zoom levels – even in track-up mode at highway speed while overlaid on Garmin City Navigator.

See image at right.

It took awhile to figure out, but my secret sauce is a FileMaker Pro relational database I wrote to analyze the polygons, associate them with the map colors and optimize/compress the terrain data. There are a couple programs – MOAGU and Mapwel – that also turn raster images into vector maps, but they really aren’t conceived for large projects and wouldn’t have given me as much control. Typically, the maps people make with these produce large files, don’t cover a very large area and only work through limited zoom ranges. I used Globalmapper for the “heavy lifting” and my database to put it all together.

Here’s an image showing the map looks through a wide zoom range. I didn’t want to see “pixels”, so I developed a technique to create smooth polygons for the little details. When you zoom in close, it looks more like abstract art, but it isn’t blocky. Zoom in farther and the polygons start to look jaggy – this is a combination of the fact that Garmin’s format only uses 32 bit coordinates plus my simplifying the polygons to keep file size down.

see: http://stephencreek.com/gpstl/zoom.png

I think I can use the same techniques to turn other forms of raster imagery into Garmin’s vector format, on as large a scale as needed. This map has tiles that correspond with the boundaries of USGS 24k quads. The majority of the individual .img files are in the 1.0 – 1.5 MB size range. Only 11 of the 87 tiles in the map are larger than 2 MB.

Garmin

• Remember that nuvi recall? I wonder if this was one of those units: GPS explodes inside truck
• Video of Garmin sticky problem that bedevils their newest handhelds at low speed; via Garmin GPSMAP 62/78 wiki
• Very cool: Southern NJ LIDAR-based map
• Garmin Internal Memory Sizes; via GPS Review forum
• A GizzMoVest case for the Garmin GPSMAP 60 series and a special RAM-Mount Montana case
• Garmin Edge 900 GPS Cycle Computer: Things We’d Like To See
• GIS with the Garmin Etrex 20
• Using a Garmin nuvi in Europe: A positive experience

Speed cameras

• Funny video of fake speed camera; via @PocketGPSWorld
• I’m hoping this kind of mobile speed camera doesn’t make it to the US

GPS tracking

• Teens send GPS-tracked Lego man into space
• Ron Wyden Suggests Secret PATRIOT GPS Tracking May Be Illegal Under Jones
• Model boat found with GPS tracker
• A better picture of that huge GPS tracking bracelet I mentioned a couple of weeks ago
• Man with machete, wearing GPS monitor, carjacks woman
• GPS devices could help stop golf club thefts

• TomTom GPS devices now available at Chevrolet dealerships across US
• TomTom’s Fleet Management Service Now Oversees 180,000 Vehicles
• More Simpsons characters come to TomTom

Geotagging and cameras

• Not sure about the market for an anti-spoofing geotagging camera add-on
• Two new Nikons with built-in GPS

The business of GPS

• DeLorme hires a new VP/GM for Connected Solutions (inReach) from Iridium
• MapQuest Integrates Traffic and Road Condition Cameras Into Maps & Directions
• More on the Mio Cyclo
• The TomTom PartnerLink web page
• TomTom Opens Map Making Facility In Pune, India

Updates

• TopoFusion Basic version 4.4 released – major update
• New Garmin software this week: nuvi 35xx, POI Loader for Windows
• ExpertGPS 4.42 and 4.43

LightSquared

• A very cool geographic feature; worth a look - The Richat Structure: Eye of the Sahara
• France convicts Google Maps for unfair competition; ordered to pay fine; via @ogleearth
• The city lights of Earth

All the news that doesn’t fit

• Gmap4 has new high-res topos; some background info on them
• Want National Geographic TOPO? Might want to grab it while you can
• Nice Magellan eXplorist 710 waterproof test video
• ShouldBeBack.com Helps You Be A Responsible Hiker
• Does GPS need replacing?

GPS deals

These are some bargains we’re currently tracking at our GPS deals site:

• NEW: TomTom VIA 1505TM 5″ GPS with Lifetime Traffic & Maps for $109 shipped
• 5″ Garmin nuvi 1450LMT with lifetime maps and traffic for $129.98 shipped
• Connected Garmin nuLink 1695 for $149.99 shipped
• Price drop on Garmin nuvi 3400 series
• $50 Garmin Forerunner rebate for student athletes
• Garmin Oregon 550 with camera for $339.95
• Garmin eTrex 30 for $249.99 with free shipping
• Garmin dezl 560LMT truck/RV GPS for $349.99 shipped

Updated GPS reviews

I’ve updated these review and resource pages with the following links:

• Garmin nuvi 1350LMT – A brief review from thejerryfink.com
• Garmin nuvi 3490LMT - Stuff magazine reviews this high-end model
• Garmin Forerunner 405 - The Runner’s Plate looks at its pros and cons

A couple of days ago, Panasonic unveiled some new cameras with GPS for geotagging photos. Nothing surprising there. What did get my attention was this footnote:

GPS may not work in China or in the border regions of countries neighboring China. Depending on the locations, it may not be possible to correctly receive the signals from GPS satellites. In such cases, positioning may not be possible, or a significant positioning discrepancy may occur. Information measured on this unit is only a rough indication. Do not use it for technical purposes.

Now I’ve been scratching my head ever since trying to figure out why this is. GPS works in China; after all, it is a GLOBAL positioning system. I haven’t heard anything leading me to believe that there is country-wide jamming. And as far as I know, the Chinese haven’t started levying tariffs on non-Beidou compatible products, like the Russians did to jumpstart the GLONASS market. Maps often have huge errors in China, but that wouldn’t give you imprecise coordinates. In a back and forth conversation on Twitter yesterday, Stefan Geens suggested that they may just be trying to get around the fact that mapping requires a license, and that perhaps the Chinese equate geotagging to mapping. This is the most plausible explanation I’ve heard, although at least one other brand does seem to work in China…

The GPS in my Lumix camera is disabled when in China. The camera gives an information message that it disables the GPS while in China. i was pleasantly surprised that Nikon does not disable the GPS in China but places some limitations on its use. The locations using the GPS in China seem to be off by about 500 ft to the west. In addition, the map function does not work in China and there are not location points for China in the database. (Via NikonUSA)

It turns out that geotagging is indeed illegal in China, and Nikon either isn’t in compliance or has found another way to deal with the situation (perhaps by generating an offset error). Clearly though, the Chinese haven’t banned the use of cell phones with GPS, which are quite capable of geotagging, though you may want to be careful where you go with them.

Finally, despite reaching out to Panasonic, I still don’t have a definitive answer on all this. It does seem clear that they are intentionally disabling the GPS in their cameras to satisfy the Chinese, but what’s posted on their website is deceptive and dumbed down:

Image via @ogleearth