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TomTom hacks - aerial photos and more

I came across some great TomTom hacks this weekend, including one for aerial photos (or any kind of raster imagery). I haven't tried any of these out, so you're kind of on your own here. As always, I'd do a full backup of the unit before trying them. Regardless, these look like some great resources for the TomTom enthusiast:

TopoFusion gets color imagery

TopoFusion Pro 3.60 has been released, adding color aerial imagery for most of the U.S. Previously, color imagery has been restricted to the beautiful high resolution (0.25 meters/pixel) imagery available for urban areas. This new imagery is lower resolution (1 meter/pixel), but it has most of the country's national forests, national parks, BLM lands, etc. The only weird thing is, Pennsylvania and Texas are red! I've included a coverage map and a YouTube demo of TopoFusion, after the jump.

First looks at DeLorme PN-40

UPDATE: Check out my hands-on review of the DeLorme PN-40.

I'm fortunate to have a DeLorme Earthmate PN-40 in for testing, and I thought I'd share some initial impressions since this unit is due to become available in the next week or two.

Like the PN-20, this new model lets you view your position on aerial imagery. But a number of upgrades promise to make this an even more popular handheld than the original:

• A dual-core processor makes map redraws and menu navigation very fast, and I can already attest to this; even at 60 MPH, map redraws were nearly instantaneous -- I saw only brief flashes of blank areas on the screen
• Tri-axial compass (meaning there is no need to hold it dead level)
• Barometric altimeter
• SDHC high-capacity SD card support
• A more detailed base map

DeLorme PN-40 and new low cost plan for aerial imagery

UPDATE: Check out my hands-on review of the DeLorme PN-40.

We heard about the DeLorme PN-40 earlier this summer, so today's announcement of its pending release this fall comes as no surprise. One new piece of info though -- they've scheduled a September shipping date.

Low cost aerial imagery and USGS quads

The other new piece of information is that you'll be able to download all the aerial imagery, USGS topo quads and NOAA charts that you want for an annual fee of $29.95. I've been merciless in my criticism of DeLorme pricing; prior to this thirty bucks would have only bought you two 7.5' quads worth of imagery. So here's a big thank you to DeLorme for giving us this deal. I can't imagine owning a DeLorme handheld and not ponying up the extra bucks for imagery.

Aerial imagery on a Magellan Triton

It's now possible to add aerial imagery to most of the Magellan Triton line, thanks to National Geographic's new TOPO! Explorer application. You can download a "SuperQuad" that includes aerial imagery and a 1:24,000 scale USGS topo map for a dollar at their Map Store.

Satellite photos to be censored by U.S.?

Vice Adm. Robert Murrett, the Director of the National Geospatial-Intelligence Agency (NGA) says that the U.S. government may need to restrict future access to certain aerial imagery. In the 2001 invasion of Afghanistan, the agency acquired all rights to images of Afghanistan, making relief efforts difficult. The NGA has said in the past that it doesn't plan to take such steps again, but Murrett is new, having been in the position only since last summer, and his comments seem to indicate a change in direction.

This is all complicated by a somewhat incestuous relationship between NGA and two commercial satellite imagery firms, Digital Globe and Geoeye, which will launch new satellites with higher resolution capabilities this year -- with the help of $1 billion in funding from NGA. Government regulations will require that the firms  degrade the imagery to 0.5 meters per pixel.

Amazingly detailed aerial photos on a GPS

I've been playing with a DeLorme Earthmate GPS PN-20 for the past few weeks, and have been pretty impressed with it overall. I've updated my PN-20 review, adding lots of screenshots and observations, so I wanted to point that out.  But one thing just blew my mind yesterday.

The image on the left below shows the PN-20 on a very faint grass path. You can actually see the trail on the aerial photo on the GPS screen. I had just arrived there when I took the screen capture below on the right. The trail is just to the left of the position indicator. It's faint enough that I might not have even seen it had it not been for the GPS.

Wow. That's really impressive. Now the trail could have been bigger when the one meter/pixel aerial photo was shot. In general though, it's not that unusual to be able to pick out things like desert tracks or anything  that changes the light reflectivity of the earth's surface. The PN-20 isn't the be all and end all, but the aerial photos are a very cool feature.  For the rest of the story, read my full DeLorme Earthmate GPS PN-20 review.

Lowrance iWAY 600C review

The Lowrance iWAY 600C is the new top of the line automotive and marine GPS navigator from Lowrance that, in addition to displaying maps, has aerial imagery of hundreds of U.S. and Canadian cities.

The iWAY 600C has a large 5" touch-screen, pre-loaded maps of the continental U.S. and Canada, plus electronic charts with depth contours for U.S. inland lakes, the Great lakes and coastal waters. It also has an MP3 player, built-in FM transmitter and 5.5 million points of interest (POIs).

25 GB of its 30GB hard drive is dedicated to maps and aerial photos. The remaining 5 GB is available to store MP3s.

DeLorme Earthmate GPS PN-20 review

UPDATE: Check out my hands-on review of the DeLorme PN-40, an updated unit that improves on the PN-20.

Finally, a GPS that displays aerial photos. The DeLorme Earthmate GPS PN-20 does just that, and displays USGS topo maps too. It is incredibly cool to be carrying a GPS that shows your position on an aerial photo. Having said that, DeLorme clearly has some improvements they need to make, and I hope they do, because this is one nifty device. Before we get into the details, let’s get up to speed on aerial photos, and why other GPS receivers lack this capability.

Aerial photos on the DeLorme Earthmate PN-20

Most GPS receivers utilize vector files — basically data files consisting of lines and points. The DeLorme PN-20 differs in that it can also accommodate images, such as aerial photos and USGS topo maps. The technical term is raster imagery, and they eat up much more memory than vector files. For a more detailed explanation of raster versus vector imagery, see What kind of maps can I put on my GPS (and what do you mean by raster and vector)?

Vector lines are redrawn, and therefore appear sharp, at every zoom level. Aerial photos and USGS topo maps, on the other hand, will only appear clear at one zoom level. DeLorme probably uses aerial photos supplied by USGS which are available at multiple resolutions – 1 meter/pixel, 4 meters/pixel, 16 meters/pixel and 64 meters/pixel. DeLorme appears to be utilizing the one meter/pixel imagery.