GPS Tracklog

Tech talk - raster vs. vector, or why has it taken so long to get aerial photos and USGS topos?

What makes aerial photos and USGS topo maps so different that we've been waiting years to get them on our GPS screens? A few companies have started offering these images in the past year. But so far, Garmin, the king of GPS receivers, has not had this capability (with the exception of limited aerial imagery of ports on some marine units).

To address this, we first need to define two types of imagery and the problems they can cause. I'll close with what's coming from Garmin and Magellan in this regard.

Switching between highway and topo maps on Garmin handhelds

Oftentimes, handheld users will load both highway and topo maps to their unit.  Garmin handhelds will show the highway maps by default. The highway map (City Navigator or City Select) for an area must be turned off before you can see the topo map. This is especially problematic when you have a lot of maps loaded and you don't know the name of the map for your current location.

In the past, I've laboriously scrolled through long lists of highway maps, deselecting each one until contour lines appeared on the map. But there is a simple solution. The instructions below are for the Garmin 60CSx, but I'm hoping this works for the eTrex series too. Perhaps someone can verify that and comment below.

From the map screen, press Menu, then Setup Map, and scroll over to Map Setup - Information. You'll see your list of loaded maps with a check mark next to each one. But rather than de-selecting them one by one, press Menu again and you'll see two choices - Hide City Select (or Navigator) and Hide US Topo, as shown in the image. Pretty cool, huh?

Thanks to Hogrod on Groundspeak for this tip.

What's a GPS mouse?

A post about a GPS mouse on Slippery Brick caught my attention this morning. To quote:

This is an interesting combination of peripherals if nothing else. A company called Navilock out of Germany who specializes in GPS products has produced a Bluetooth enabled mouse that also acts as a GPS receiver. This is convenient in that if you are looking for a powerful GPS antenna and you are going to be using a mouse anyway, you can now just get them both in one device adding less clutter to your workspace.

Sorry guys, but you're wrong. This thing ain't no mouse. The term "GPS mouse" refers to the shape and size of the device, and has come to mean any wired or wireless GPS receiver that doesn't come with any sort of interface. It merely outputs position data to a laptop, cell phone, etc.

Top posts of 2006: The year in review

While blogs like this have a lot going for them, one of their weaknesses is that old posts quickly get lost, so I like to do an annual review, and highlight more recent popular posts in the sidebar. With that introduction, here are the top 20 most popular posts from 2006, and a few others to boot:

1. SiRFstar III - Why it's a big deal - The chipset of choice. It is so cool to get a signal lock indoors!
2. Custom POI's - 6 million POIs not enough for you? Maybe the NAVTEQ or Teleatlas database doesn't have your favorite fast food chain. Check out these resources. Someone else may have already done the hard work for you.
3. Handheld GPS recommendations - 'Nuff said.
4. Consumer Reports rates GPS receivers - People value these independent reviews.
5. Garmin City Select vs. City Navigator - This has got to be one of the most common questions out there for owners of Garmin handhelds wishing to use them for auto navigation.
6. Automotive GPS recommendations - 'Nuff said.
7. Hacking eXplorist 100, 200 and 300 GPS receivers - Now you can get a PC interface cable for these Magellan units.
   
8. Why have a barometric altimeter? - The joys of knowing your elevation and elevation gain.
9. How to create custom POIs for your Garmin GPS - If you looked at item number two, but couldn't find what you were looking for, here is a DIY resource.
   
10. Why have an electronic compass? - Didn't REM do some songs about this (Standing Still, Stand)? How to tell which way you're facing while standing still.
    
11. GPS rebates and deals - Everybody loves a deal.
    
12. Does the nuvi have a weak feature set and interface? - Maybe, but much depends on what you are looking for. The nuvi is still the best at lots of things.
    
13. Garmin nuvi compared to Mobile XT - More on that last one.
    
14. Garmin to focus more on pre-programmed SD cards? - Can you say "planned obsolescence?" How about "legacy product?"
    
15. Free maps of Japan for Garmin GPS receivers - Everybody loves getting something for free.
    
16. GPS for your car: Factory-installed or aftermarket unit? - Puh-lease. This is a no brainer!
    
17. Can my GPS be used to track me? - The short answer? Not unless it has a transmitter.
    
18. Pros and cons of PDA-based GPS receivers - They do it all, but they sure are fragile. Now where did I put my stylus?
    
19. Convert National Geographic TOPO (.tpo) files - GPS lovers that use TOPO should send Robert Lipe a thank you!
    
20. DesktopEarth - Eye candy for your desktop.

50 GPS message boards

Call them message boards, discussion groups, online forums, or some other combination of those terms -- Connecting with other folks on the web, who are using your particular brand of GPS can be one of the quickest ways to get an answer on anything from basic noobie queries to perplexing technical questions. Especially helpful are groups that focus on particular brands and models of GPS.

A few caveats before the list of message boards…I've tried to screen out those groups dominated by spam. Also, some of these groups overlap, and they vary greatly in posting volume. Speaking of which, I have one tip for the many Yahoo groups below -- you may want to choose to view messages on the web only, rather than by email, lest your inbox quickly become clogged. Finally, be sure to drill up and down through these websites. There were just too many forums to list them all, and there are other great message boards out there.

Converting GPS file formats

What to do? You've got a .tpo track file from TOPO! that you want to put on your GPS. or you're dying to see how a .gpx file looks in Google Earth. Well, you're not alone. Thousands of others GPS aficianados struggle with the same alphabet soup, and concommitant translation problems. Fortunately, solutions are at hand. Let's look at some file converters.

GPSBabel

Developed by Robert Lipe, GPSBabel is my new favorite in this category, thanks to its newfound ability to convert .tpo files used in National Geographic TOPO! Heck, just take a look at this file compatibility list to get an idea of its utility. Most people will feel quite comfortable using their GUI interface.

How to load Garmin TOPO maps to your hard drive

Last month my wife and I took a mountain biking vacation in the Lake Tahoe area and, of course, we took our GPS receivers along for the ride! While I posted a trip report, complete with GPS tracklogs,  I haven't quite fessed up to one thing.

You see, I took my laptop along for managing waypoints, tracks and maps, but forgot to take my Garmin U.S. TOPO CD. I was incredibly disappointed, since my wife and I were both sporting handlebar GPS mounts so we could keep an eye on our progress and to help us keep on track. But I'm posting today to keep you from suffering a similar fate. And if nothing else, the method described below keeps you from having to load the CD every time you want to put a new topo map on your GPS.

Putting Garmin TOPO maps on your hard drive is incredibly simple, and it has to do with the installation. Create a folder on your hard drive and copy the contents of the CD's to it, including the setup disc. Then navigate to that folder and run setup from your hard drive, and not the CD. That's it!

Best GPS traffic service: XM or FM/TMC?

Reader Martin L. emailed me the other day, asking about GPS traffic services, among other things. I couldn't really tell him which service,  XM NavTraffic or TMC - the Traffic Message Channel (FM) was better, so I suggested he check out the GpsPasSion traffic forum. Martin came across this thread, comparing XM vs. FM traffic services for GPS receivers. Though the sample is small, it seems pretty clear that XM NavTraffic is the hands-down winner.

But this led to another issue. Martin lives in NYC - urban canyon land, so he wants a GPS with the SiRFstar III chipset. Well, here's the weird part. Garmin hasn't paired these technologies yet. SiRFstar III receivers use FM/TMC, while XM receivers use the older chipsets. But that is about to change.

GPS myths

GPSReview.net lists 10 myths about GPS. I've covered a number of these in detail in the following posts:

• Can my GPS be used to track me?
• GPS for your car: Factory-installed or aftermarket?
• SiRFstar III - Why it's a big deal
• Does heavy cloud cover affect GPS reception?
• Flying with GPS on commercial airliners

Why have a barometric altimeter?

Quite simply, the primary reason you would want a barometric altimeter in a handheld GPS is for more accurate elevation readings. This is especially useful for bikers, hikers and atheletes in training. You can use the resulting data to track your progress and maintain an accurate record of your trips. A barometric altimeter can also help you accurately place your location on a topo map.

Furthermore, you can use the altimeter to forecast weather trends. A falling barometer can indicate worsening weather. See the barometer section of this review for some really cool things you can do with your GPS!

GPS-based altitude error is generally worse than latitude/longitude error. A good explanation of why barometric altimeters are better than GPS-based elevation data comes from GPSInformation.net. Here is another good resource -- an electronic compass and barometric altimeter FAQ from Garmin.

Finally, a barometric altimeter is often paired with an electronic compass in higher end handheld GPS receivers.