Last Week’s Column and a New GPS Constellation

First off, let me offer my prayers for those who were affected by the powerful earthquake that occurred in Haiti yesterday (Tuesday). You can view USGS maps of the area here. ESRI is offering Disaster Response and Assistance. God Speed.

I received some feedback from last week’s column “PDA vs. Tablet: Is the War Over or Just Starting?” and also some additional comments.

While I focused on the tablet side of the equation last week, it’s prudent to make mention of the PDA side of the equation.

But first, one reader pointed out that they use “convertible” tablet computers for GIS data collection. The reader comments…

“I think it would have been at least worth a mention to bring up the convertible notebooks that operate as tablets in your article.  Now that we do all of our inspections electronically, our field inspectors use Panasonic Toughbooks w/the screen rolled around, in the field.  Everything they do is w/the pen since the keyboard ends up underneath, so technically, they are using it as a pen based tablet.  Also, we are using the handwriting part and it works pretty good, not great – the one place we do use it every time is to capture the signature of the person we inspected (as an image, not to recognize the characters).  Finally, they all have and use a Pentax bluetooth printer to leave a paper inspection record at the site when they are done.  A pdf copy of the document that prints out is kept in the system as the official record.”

There is a pretty significant manufacturing base of convertible tablet computers. For example, Fujitsu used to have a multi-model line-up of slate tablet computers; now they just have one. But, they have a multi-model line-up of convertible tablets. It didn’t used to be that way. I think the reason is somewhat obvious. The convertible can easily be used as the user’s default notebook computer. Although you can use a slate tablet in the same manner (as your default notebook computer), it just doesn’t work out that way. For me, it was due to the smaller screen size and slower processor that I didn’t use my slate tablet as my default notebook computer.

PDA Side of the Equation

As much as tablet computers have hit a number of speed bumps, the PDA (personal digital assistant) has taken a similar path. They weren’t always popular. Remember the Apple Newton?

Not until the Palm V was introduced in 1999 did the PDA really gain mass popularity. At nearly the same time, Microsoft introduced a Windows Operating System for handhelds called Pocket PC 2000.

Since that time, PDAs have skyrocketed to the point of smartphones such as the BlackBerry, iPhone, Nokia N-Series, HTCs, Palm Treo Pre/Pro, and now the Google Nexus One.

From a handheld GIS data collector point of view, mass acceptance of handheld computers has helped pave the way for improved “industrial-strength” handhelds. Whereas there used to be a myriad of industrial handhelds based on proprietary operating systems in the 1990s used for applications such as meter reading, barcode scanning, surveying, and GIS data collection, they have become somewhat standardized on the Windows Mobile operating system and borrowed many developments from their consumer brethren.

However, the handheld GIS data collector business is still fuzzy. Do I use a dedicated industrial handheld (somewhat expensive)? Do I use a consumer PDA (cheaper but more fragile)? Do I use a smartphone (I already have one, so really cheap)?

I’ve used the first two extensively. I’ve never tried using a smartphone to run ArcPad or other GIS data collection program. I’ve known some people who have tried and the problem usually ends up being the lack of system resources to run the phone and a GIS data-collection program at the same time or Bluetooth connectivity problems when using an external GPS receiver.

With a consumer PDA (such as the IPaq), my experiences were so-so. They are small and convenient, but the ruggedness factor always worried me, and I usually had trouble reading the screen in bright sunlight. Battery life was always an issue, and working in the rain was not possible. There are ruggedized cases available for consumer PDAs, but I never purchased one because I have several PDAs and the ruggedized cases are model-specific for the most part.

With industrial PDAs, my experience has been pretty good. The only data I ever lost was when I left the handheld on the roof of my rental car and drove back to the hotel. I found the heldheld, but unfortunately, so had the tires of a half-dozen cars.

Increased competition in the industrial handheld market has brought prices down. TDS/Trimble just reduced the price of its Nomad 800B to $1,449 to compete with Swedish newcomer Handheld. Juniper Systems and Getac/MiTAC are also gaining market share. This is good news for the user community as more competition usually results in better and cheaper products.

A Quick Note on the New 24+3 GPS Constellation

Earlier this week, the US Air Force announced they will be transitioning the GPS constellation to a new configuration. The new constellation will have three new slots for satellites and will improve the quality of GPS coverage worldwide. While there is already 24/7 GPS coverage all over the world, the new configuration will result in more satellites in view at a given time as well as a reduced PDOP. PDOP is a measure of the quality of the GPS constellation being tracking by a GPS receiver at a given time and has a direct affect on GPS accuracy.

For the mapping and surveying community, this is probably the most significant announcement since Selective Availability was turned off nearly 10 years ago.

Stay tuned for a detailed article in my GPS World Survey Scene column in the next week or so.

Thanks, and see you next week.