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Archive for the 'GIS' Category

The Intel Classmate Convertible: A Cheap GeoPad?

A few years ago, the One Laptop Per Child initiative (OLPC) created what some consider to be the original netbook concept: a small, light-weight, rugged low-power inexpensive laptop, with a target price of $100. It had its own custom operating system, Sugar, designed to be easy to use for its target audience of young children. Perhaps because they felt a bit threatened by the OLPC concept, Intel came up with a competing line of small laptops that ran Windows XP, the Intel Classmate line. Earlier models were strictly standard clamshell laptops, but early in 2009 Intel introduced the Classmate Convertible, a touch-tablet model that seemed to me to meet at least some of my requirements for a GeoPad, a portable GIS workstation:

  • Long battery life (Intel specs it at 6 hours with the WiFi and webcam off)
  • Lightweight (about 3 pounds with the 6-cell battery)
  • 8.9” diagonal LCD display, 1024 x 600 (standard netbook resolution)
  • Rugged. Designed to take the abuse that young children can dish out, it can survive a 0.5-meter drop on a concrete floor on all edges (non-operating), and a 0.4-meter drop onto plywood while on but not doing disk operations. It’s also described as “splash-resistant”, which means that some water splashed onto it shouldn’t cause a problem, but it’s not waterproof.
  • Impact-resistant plastic shell, with rounded corners to reduce impact effects.
  • A 60 GB shock-mounted PATA hard drive.
  • Windows XP OS, allowing for good application choice; you can now get it with the Windows 7 Starter edition.
  • Atom 1.6 GHz processor (standard for netbooks); 1 GB RAM, expandable to a maximum of 2 GB.
  • Touchscreen –convertible; you can use it in standard clamshell mode, or flip the screen around and down to use it in tablet mode. While it doesn’t come with a touch stylus, it has “palm rejection” technology, so that touching it with your palm or wrist accidentally, or even resting your hand on it, won’t register as a touch; only the stylus or hard presses with your finger will register.
  • Full network capability, with wireless 802.11g and an Ethernet port.
  • Two USB ports, VGA external monitor port, SD card slot, headphone/microphone jack, full keyboard and touchpad input.
  • A built-in 1.3-megapixel webcam that can be rotated to face towards you, away from you, and at 90 degrees so that it can be used in tablet mode. So you could use it in the field to snap a photo in tablet mode, then draw directly on the captured image. Also has a built-in microphone for use in VOIP or in-field recording.
  • Finally, reasonably priced; you can find it online for about $450.

Although Intel designed the system, they don’t actually manufacture or sell it; they released the reference design and specifications to OEMs. The OEMs in turn wholesale it to individual retailers, who sell it under a wide variety of names. While retailer software configurations can vary significantly, the basic hardware is the same from all of them, as is the basic software toolkit. So unless you’re looking for a specific set of additional software (like MS Office), the cheapest model may well be the best choice. Here are some links to vendors of the Classmate Convertible:

This was the only inexpensive touchscreen computer I could find whose specs came close to meeting my requirements for a GeoPad. But the only way to find out if would prove useful in the field was to order it, configure it with software and additional hardware, then use it for an extended period. I got approval for the purchase, and have used it now for about half a year. How well does it work hardware-wise as a GeoPad? That’s tomorrow’s post …

… But here’s a preview: it’s pretty good, but it’s not perfect. It has one major drawback that makes using it in the field less than ideal. But I still find it a useful field companion.




Choosing A Laptop For A Cheap GeoPad

A GeoPad is a field-capable portable PC workstation configured for use with geographic applications (GPS/GIS); see yesterday’s post for more details. The GeoPad website has a full page on what to consider when selecting hardware, and is definitely worth a look. Much of that site is oriented around the purchase of standard field-ready laptops, none of which you could really call cheap. To put together a budget GeoPad, I concentrated on finding one that would meet as many of the following requirements as possible:

1. Relatively inexpensive; less than  $1000, preferably much less.

2. Durable. For standard laptops, 1-year laptop failure rates due to manufacturing defects run at about 10-15%, and 3-year at 15-25% under normal use (up to 31% overall after you factor in “user clumsiness”).  It’s likely that these failure rates would be greater for a laptop that gets jostled in a backpack, or used on a bumpy road. A mil-spec “rugged” PC would be the optimal choice, as it meets US military requirements for shock resistance, temperature, dust, etc.., but these are way too expensive.  A Panasonic Toughbook would be a great choice, but it’s $3000+ for even the most basic configuration. And you have to be careful about the word “rugged”, as there’s no standard definition. For example, the HP Elite 2730P calls itself rugged because it passes the military tests for temperature, dust and altitude, but not the impact/drop tests that reflect the kind of abuse it could see in the field.

3. Touch screen convertible PC. The GeoPad website emphasizes the utility of a touch screen interface for use in the field, and I totally agree. I’ve tried using my Acer Aspire One netbook in the field, with a clamshell configuration, and it just doesn’t cut it. To use it, you have to open it up, and enter data with the keyboard and mouse, something you can’t do standing up unless you have 3+ hands. A touch screen allows two-handed use at a minimum; combine it with a good working tablet case, and you can easily use it without dropping it.

Convertible means that you can use it either in standard clamshell mode, or rotate the screen and fold it down to use it in tablet mode. I wanted the option to use it in standard mode as well as tablet for added flexibility in data entry. You can get “slates”, tablets with no built-in keyboard, and then attach a keyboard via the USB connector; IMO, too clumsy and inconvenient in the field.

4. Good screen visibility in outdoor conditions. Most laptop screens don’t do well in outdoor conditions, especially in direct sunlight; the contrast gets washed out. Some rugged PCs come with special transmissive or transflective screens that will work well in outdoor conditions, but they can be very expensive. To reach my price range, I expected to have to compromise somewhat on this, but still wanted to find one that could be used under some outdoor lighting conditions.

5. Windows OS, because of the larger selection of free software available under this platform.

6. Respectable battery life; at least 4 hours under normal use.

7. Decent memory; 1 GB RAM, plus at least 30 GB storage space for software and data.

8. Light weight and compact size.

9. Plus as many typical notebook features as possible (USB ports, VGA output, wireless, Bluetooth, webcam, memory card slot, etc.)

The cost restriction narrowed down the field immediately; I couldn’t find a single “rugged” laptop available below $1000. Some standard touch screen laptops are available in that price range, in particular some of  the HP tx2 models which are just under $1000. But HP has the worst record for 1-year and 3-year failure rates in the industry (15% and 25%), and reviews have complained about the mediocre battery life. I was hopeful that some netbook touch screen convertibles might do the job, like the Asus T91 or Gigabyte 1028 series. While not “rugged” laptops, they offer a touch screen, 5-hour battery life, low weight, and fairly low cost ($500-700). But while they’re “touch screen” PCs, they have a drawback that would make them hard to work with in the field. A touch anywhere on the screen of these netbooks, even if it’s an accidental brush by your finger or palm, is registered as an input; if you’re trying to enter data on-screen, this can result in a lot of mistakes and frustration. More advanced tablet PCs get around this problem in one of two ways:

- A “digitizer” mode, where the only input recognized is that from a special stylus pen.

- “Palm rejection”, where the touch screen driver can recognize and reject minor contact from your palm or finger touches, but recognize firm contact.

So these cheap netbooks might not be a good choice because of this touch screen issue. The Hp tx2 models offer the option of being used in either basic touch screen or digitizer mode, but are much more expensive and might not be durable enough; at $1000, it seemed risky to go for this model. I almost gave up on the idea of a cheap GeoPad until, by accident, I found a fairly inexpensive laptop that seemed to meet most of my requirements. But that’s the next post in this series  …




A Cheap “GeoPad” – Putting Together An Affordable Field-Capable GIS/GPS Workstation

Last week, I posted my feature “wish list” for a handheld GPS unit designed for advanced fieldwork by scientists, mappers, technicians, etc.. One step up from that “dream” GPS unit are the mini PDA-like GPS devices / handheld computers already on the market from companies like Trimble, Ashtech, Leica Geosystems and many others. These typically have somewhat larger display screens, usually touch-enabled, and often run Windows Mobile. These can be a good choice for field data acquisition, but also have some drawbacks:

  • The screen size is fine for data acquisition, but can be too small for actual mapping work (both viewing and creating maps)
  • Even the cheapest units will start at over $600; more expensive units can easily run into thousands of dollars
  • The software for data acquisition and mapping is limited by the OS; there’s a lot less available for Windows Mobile than for standard versions of Windows (XP/Vista/7)
  • Windows Mobile isn’t the greatest OS in the world, and development of it has been very slow
  • The software that is available is often expensive
  • Processor speeds tend to be slow
  • Input is often by stylus only, which can be slow
  • Storage space for datasets can be severely limited

One step up (or maybe sideways) from these PDA devices is the concept of a GeoPad, a field-capable full PC running a desktop operating system like Windows XP. I’ve been keeping my eye on these for a while now, as this isn’t a new concept. The University of Michigan’s GeoPad website talks about developing the concept since 2003; they define a GeoPad as:

a rugged Tablet PC equipped with wireless networking, a portable GPS receiver, digital camera, microphone-headset, voice-recognition software, GIS software, and supporting, digital, geo-referenced data-sets.

The advantages of a GeoPad over a PDA-based solution (which the GeoPad site calls a GeoPocket) include:

  • Larger screen area, better suited for mapping, and easier for multiple people to view
  • Full Windows OS, which opens access to all Windows-compatible applications
  • Greater storage space (hard drive or SSD), for more datasets
  • More input options: full keyboard, stylus, mouse/trackpad

But it has disadvantages compared to PDA-based solutions as well:

  • Larger and heavier
  • Shorter battery life
  • Less rugged

But the biggest obstacle to GeoPad adoption might be cost. The GeoPad website lists a number of hardware/software combinations, with costs of about $4000-$5000; while the models are a bit out of data (circa 2007), costs of hardware and software comparable to the ones they list indicate that prices haven’t dropped as much as they have for other computer hardware.

About six months ago, I was asked to figure out whether it might be possible to find a combination of cheap hardware, and free/inexpensive GIS/GPS software, that would let you put together a GeoPad-type system for significantly less than the $4000-$5000 range without sacrificing too much in features. Over the next few months, I’ll be writing a series of posts on how I put together a usable GeoPad system for under $700 in hardware and software costs. It’s not a perfect system;  I’ll point out where it’s deficient, and how to work around some of those deficiencies. But you’ll find some of those deficiencies on expensive systems as well. Overall, my cheap GeoPad does most of what the more expensive systems do, at less than a fifth the cost. And even if you don’t go the cheapest route, hopefully you’ll find some of my experiences useful in putting together a GeoPad system of your own.

PS If you have no interest in this topic, don’t worry; I won’t be focusing exclusively on this. Posts on standard blog topics will continue.




Merging Raster Imagery With MicroDEM

I use to recommend the TatukGIS Viewer as a good free program for merging raster imagery and export it in georeferenced full resolution, but as last week’s post indicated, the latest version of it drops this functionality. Someone asked me for a recommended free alternative, and for now I’d pick MicroDEM for that. It does have some limitations:

Continue reading ‘Merging Raster Imagery With MicroDEM’




Humanitarian GIS Aid Through MapAction

The recent earthquake in Haiti reminds me to give a plug to MapAction, a non-profit, volunteer humanitarian organization that provides rapid mapping and GIS support to humanitarian relief efforts after major disasters. Less than 12 hours after the Haiti earthquake, they had a four-man team on the ground to provide mapping support to relief agencies and workers. Check out their 28 deployments to date on this page, and if you’d like to help, there’s a donations page here.

Addendum: James Fee has a long list of Haiti-related Geospatial Community Links, including data sources and relief agencies, plus a link to GISCorps, an organization similar to MapAction.




Watch Out If You Upgrade To TatukGIS Viewer 2.0

A few years ago, I had several posts on the TatukGIS Viewer, a free program for viewing vector and raster GIS data. IMO the most valuable feature of this program was the ability to export georeferenced raster imagery of the view, with a great deal of flexibility in the resolution of the final output. Recently, TatukGIS announced a major upgrade to version 2.0 of the Viewer, the main improvement being on-the-fly reprojection of raster/vector data; previously, all the data had to be in the same coordinate system. Unfortunately, after trying it out, I discovered that they have removed the raster export function completely; it’s only available in their GIS editor, which costs $350. It’s still not a bad GIS viewer, but with the loss of this export function, I’d have to say you’d be better off learning how to use one of the free GIS viewers/editors that offer either on-the-fly reprojection, raster export, or both (e.g. gvSIG, qGIS, MapWindow, and many more – check my Big List Of Free GIS Programs posts for more). Plus, with these free/open-source options, you won’t have to worry about features being removed arbitrarily.

If you still want to try the new version of TatukGIS Viewer, make sure not to select the option that uninstalls the old version, like I did. Fortunately I had an older installer archived, as TatukGIS has removed all links to older versions.




Check Out The GISVM Virtual Linux GIS Workstation With Your Browser

Over a year ago, I posted about GISVM, a Linux GIS workstation in a virtual package that could be run in free VM software like VMWare Player or Virtual Box. You can now try out a more recent release of this package (christened Arramagong, and distributed at the 2009 FOSS4G conference in Australia) in a Java-based virtual machine viewer at the click2try website. You need to register (for free) to save data and settings, but you can try it out without registration. You’ll definitely need a broadband connection to run it, and there’s a connection test to make sure your network link is up to it. Once running, display refresh speed is adequate enough to load up apps and try them out. Wouldn’t want to run the apps full-time on this service, but that’s certainly not the intention for this package  – it’s just to show off what’s available in the distribution. If you like it, you can always download the 1 GB+ full distribution and a free virtual machine environment, and run it at acceptable speed on your own computer.

arramagong

In addition to the apps you see listed above, it also has qGIS, uDig, RGeo, openJump,  and MapTiler




Two Free Textbooks On Geospatial/Geostatistical Analysis

A Practical Guide To Geostatistical Mapping by Tomislav Hengl

Geostatistical mapping can be defined as analytical production of maps by using field observations, auxiliary information and a computer program that generates predictions. The purpose of this guide is to assist you in producing quality maps by using fully-operational open source software packages: R+gstat/geoR and SAGA GIS. Materials presented in this book have been used for the five-day advanced training course "GEOSTAT: spatio-temporal data analysis with R+SAGA+Google Earth" that is periodically organized by the author and collaborators. This is an open access publication!

In addition to a free downloadable PDF copy of the book, you can:

Via Slashgeo.

 

Geospatial Analysis: A Comprehensive Guide To Principles, Techniques And Software Tools by de Smith, Goodchild and Longley

Topics covered:

  • Geospatial analysis concepts
  • Core components of geospatial analysis, including distance and directional analysis, geometrical processing, map algebra, and grid models
  • Exploratory Spatial Data Analysis (ESDA) and spatial statistics, including spatial autocorrelation and spatial regression
  • Surface analysis, including surface form analysis, gridding and interpolation methods
  • Network and locational analysis, including shortest path calculation, travelling salesman problems, facility location and arc routing
  • Geocomputational methods, including agent-based modeling, artificial neural networks and evolutionary computing

Full text is available online, including diagrams; text is organized by chapter, searchable, and includes Google Translate buttons in 10 different languages. A free PDF is available with purchase of the book.