GPS Tracklog

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

Most innovative handheld GPS of 2007

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.

DeLorme PN-20 with aerial photos and USGS topos

DeLorme has announced an anticipated ship date of the week of January 15 for its Earthmate GPS PN-20. The long-planned Earthmate PN-20 ships with the national edition of DeLorme's Topo USA 6.0 and is capable of accepting USGS topo maps and aerial imagery using DeLorme's proprietary Aerial Data Packets (ADP).

The PN-20 also comes with routable maps covering major highways and roads, and a world-wide base map. Here is a link for more information on ADP's and included maps.

I criticized the cost of ADP's in my book, GPS Mapping, which (at that time) averaged out to around $155 per USGS 7.5 minute quad). DeLorme appears to have dropped the price down to $0.25 per square kilometer, but by my calculations, that's still almost $40 per quad.

Regardless, I'm happy to see raster imagery on ruggedized handhelds. Bushnell is also introducing models with this capability. Over time, I hope we'll see some handhelds using non-proprietary formats for this sort of imagery, but I expect that will take a few years.

Bushnell GPS to feature aerial photos and satellite imagery

Bushnell has announced two new handheld GPS receivers that can accommodate aerial photos and satellite imagery (and apparently USGS topo maps). This comes hot on the heels of Lowrance announcing their iWAY 600C auto receiver. Assuming someone else doesn't beat them to the punch, Bushnell will have the first non-PDA, consumer handheld GPS with this capability. Outdoor enthusiasts have been waiting a long time for a ruggedized GPS with this capability.

There are two models -- the Onix200 and Onix200CR -- the only apparent difference being that the CR has a color screen with higher resolution. Amazon says that the Bushnell Onix200 will be available sometime after December 22. The Onix200CR is due in February 2007.

Bushnell is hyping a screen layering feature, but it appears to only layer a navigation compass on the screen, rather than allow you to blend topos and aerial imagery. I'm a little disappointed that you can't layer topo maps and aerial photos, but another concern is cost.

At first glance this doesn't look too bad -- $1 per map or photo, 25 for $20 or an unlimited annual subscription for $79. Which begs the question, after a year do I own the imagery or do I have to download it again every time I want to change images?

And consider this quote: "The ONIX200 series unit will store up to 12 photography (satellite or aerial) downloads at one time. Choose images of the same land at different levels of zoom, or broaden your coverage area by storing photos of separate areas."

With only 32 MB of user memory, the Onix200 series will accept only 12 images. And from that quote, and the layout of the download site, I assume that each time you change zoom level, it's a different image and therefore another map or photo you are charged for.

Sounds a bit limited to me. Maybe Garmin will bring this capability to CES.

Fast loading topos, aerial photos and weather radar on Google Maps

I've posted before about sites that mashed up Google maps with topo maps, and I haven't been all that impressed to date. Finally someone got it right though. Acme Mapper uses TerraServer imagery, providing access to topo maps and aerial photos (DOQs). And it loads fast. Now if it only had a GPS interface!

Via The Map Room

Related post:

• Convert Google Maps search results to GPS waypoints
• Get maps and aerial photos online: TopoFusion
• Free topos and aerial photos: USA PhotoMaps

Fun with aerial imagery

You can do this too, using GeoGreeting! Just spell out whatever you want (up to 40 characters). You can even email the link to someone, giving them a geo-message. My first one last night was "Hi Honey."

Here is the link to the GPS Tracklog image above. I found it to be a bit slow in loading, but it's still fun. Via OgleEarth.

Satellite imagery and aerial photos on your GPS

Earlier this week, Lowrance announced a new GPS receiver, the iWAY 600C. What makes this unit so special is that it can display satellite imagery. It looks like they will beat DeLorme, manufacturers of the fabled Earthmate PN-20, to the punch (though no release date has been set). Actually, Garmin already has marine units that can accommodate aerial photography.

This is a rare feature, and one reason is memory. The points and lines you see on your GPS screen come from data files, not images. It takes a lot more room to store the latter. 25 GB of the iWAYs's 30 GB hard drive is devoted to maps and satellite imagery. But hey, if they can make an 80 GB iPod, this stuff can't be to far away for GPS. Hopefully, the manufacturers will get it right, and not charge us extra for imagery that is available for free on line.

Get the Lowrance iWAY 600C at Amazon.