Most of the questions I receive about map making have to do with proprietary software. That is, while some software seems “universal,” the truth is that files produced in one version are not compatible in a competing version. The success, therefore, is learning to minimize proprietary formats.

The obvious…

The simplest solution is to limit products that only save data in proprietary formats. The government-funded GPS satellite cluster is normally interpreted in a standardized, public format established by the US Coast Guard called “NMEA.” The GPS receiver will read the satellite information and transmit NMEA lines as ASCII strings. Most important is the summary line, or ‘fix data’ line, known as the GGA line. This line transmits the time, latitude, longitude, quality of fix, number of satellites, horizontal dilution of precision, altitude, and some other information. Because it is a simple ASCII line, it is easy to write software that seeks out this transmitted line and parses out the needed information. The most common commercial GPS receivers are produced by Garmin and Magellan. However, to keep customer’s cash, Garmin and Magellan use mapping software that relies on proprietary transmitted information so you cannot use other mapping software and you cannot use other brands of receivers. In summary, make sure your software can read NMEA format. In fairness, both Garmin and Magellan produce excellent products and more and more third party software can allow for Garmin and Magellan input. Read the fine print!

In a similar circumstance, it seems that every GIS program uses its own proprietary format. Rather than regurgitate a litany of acronyms, let’s just assume any product you use will have its own file format. While ESRI shape files (explained in another blog) are the most commonly shared, not all GIS programs allow for shape files. My advice: if you are not sure, save your data as a text (.txt) or comma-separated values (.csv) format. These are more universally read.

The subtle…

Have you ever been frustrated because you thought you were using a standard file format and the program would not read the file? For starters, have you received a .docx yet? I recently worked on an interesting problem with a colleague of mine that was a model for subtlety. Todd wanted to use SOLO Field on a Nomad Computer for collecting GIS data. His background map was a trimmed image from a much larger air photo. Both the original and trimmed map were saved in the standard geotiff (.tif) format which is read by SOLO Field. However, every time he loaded the map, the program would crash. We thought the problem was that the file was too big (~30 MB), but that wasn’t the case. It ended up that he used an ArcGIS product to trim the image and for some reason, the new image could not be read in a non-ESRI GIS. He went back and trimmed the original image in SOLO Office and everything worked smooth. Moral of the lesson: just because the file format is on the software list, doesn’t mean it will work.

No. However, the ESRI shape-file format with the multitude of files is the standard for most industries and academia. So when you collect your data, make sure you can output as standard shape files, composed of the minimum triad of .shp, .sbx, and .dbf files. (The .prj is valuable if you have an assigned projection.) I should also chime in that ESRI continues to dominate the GIS market because they do make amazing products.

So why go with someone else? Try cost, ease of use, memory drain, and the fighting spirit to stick it to the man. Most software is essentially a trimmed down and specialized version of ArcGIS, tailored toward a specific industry. I have written previous blogs about the amazing and free MapWindow and also the very powerful Manifold GIS system. Of course, I continue to be amazed with the power of Google Earth…

Google Earth in the field? Yes!

…which leads me to today’s blog. Recently, I was doing field work in the Boundary Waters area of northern Minnesota. Without a doubt, the Boundary Waters is the most lovely mosquito and wood tick hatchery in the lower 48. But I digress. Our fearless field party got lost under my direction. After a while, all the ponds and mossy outcrops look the same. In desperation, I sent one of the folks (we will call him “CyberKnife”) back to the car to dig up my ToughBook and GPS receiver. I popped up Google Earth though we did not have an internet connection and was amazed by how much detail was stored in the cache. Years ago, I would use the program ExpertGPS for mapping because it had a deep cache, and I still find the program fantastic for flat, back maps and airphotos. I haven’t used Google Earth in the field because I didn’t think it would work. Well, it worked fantastic! The only issue was that the COM port assigned to the GPS was too high for Google Earth so that will need to be addressed.

OK, so what to use for collecting data in the field? The industry standard is still dominated by ESRI and ArcPad is there solution for data collecting. If you have a PC and want to plot lines or points on topo maps, I am still a fan of National Geographic TOPO. Need road, airphotos, and other layers? Well, jump on the Google Earth bandwagon. Once MapWindow allows for higher COM port numbers, I’ll recommend MapWindow for all ‘real’ GIS needs in the field.

(*As long as I can claim some bandwidth on the global web, I’d like to wish my pal Brian and the rest of the GIS crew on the edge of the northern California fires good luck. Soot-covered fireman get all the thanks on the local radio, but there are lots of other folks working long shifts behind the scenes.)

Recently, three colleges converged in western Nevada for four days of field paleontology. Over thirty students participated in a series of field tasks that represented different kinds of field scientific work. The tasks ranged from classic description to modern collection techniques. For the latter, the students mapped a trilobite-rich area using a Nomad computer and SX Blue II sub-meter GPS from Walcott Scientific.

Students found the gear not too cumbersome to wear and use in the field.

Trilobites are extinct arthropods, related to modern insects, crabs, and lobsters. In the Cambrian period, about 500 million years ago, they ruled the seas. Deep water deposits of that age are rich in trilobite fossils. The field exercise was carried out in Esmeralda County, Nevada in glorious weather. The students divided into teams of four members and each team had a guide to the common trilobites. Then, they students scurried about the hills looking for fossil-rich zones. When they found a particularly rich area, the students logged their location with an SX Blue II sub-meter GPS that communicated to a TDS Nomad via Bluetooth.

Nevadia weeksi, common trilobite in the lower field area.

Data was collected as a point-based shape file in ArcPad, set against a topographic map downloaded from a state of Nevada GIS website. In addition to the location information, the students listed the dominant fossil genus and estimated the age. Both the Nomad and GPS worked without a hitch and there was plenty of battery life at the end of the project.

Back at the college, the data was transferred to MapWindow GIS and sent via Shape2Earth to GoogleEarth as a .kml file. This process took less then five minutes. Each student was then e-mailed the .kml file so they could see for themselves just how the fossil bugs were distributed in the field area.

This assignment, and similar ones I have done with my courses, really shows the students both how easy it is to collect data in the field, and how GIS adds value to a project. The Nomad proved an excellent tool in the Nevada desert with the bright screen and rugged design. While many researchers still use tablets and PCs in the field, the use of small PDA data collectors is more efficient on cost, weight, and battery life.

Your buddy / boyfriend / boss hands you a PDA for the first time and tells you to ‘figure it out.’ Where do you start? Can you understand your way around the computer? This short blog is meant to be a sort of triage to get you through a Windows Mobile device, like the Recon or Nomad.

It sure looks like Windows…

Windows Mobile look and feels like Windows XP even if the code below the surface is different. (Windows Mobile evolved from Win.CE so all the various operating systems share some similarities.) Many of the features, such as the Start button, Program list, menu buttons, etc., function in the same way so if you use a PC, it will be terra cognita. Here are the important differences:

1) When you click the X in the upper right corner, you usually only close the window, not the program like in Windows XP. You will need to close the program through a menu option or it will run in the background.

2) Use the File Explorer to find missing files, even when your files are on a CompactFlash or USB drive.

3) Most PDAs only have ‘USB out’ for synching to a desktop computer. That means you cannot plug in a USB device like a printer or flash (thumb) drive. The Nomad does have a ‘USB in’ option.

4) Can’t see the screen because it is dark? Try holding down the power button for a second or two and that should bring up the brightness. If you hold it down too long, you will enter a ‘soft reset mode’ which your probably don’t want to do.

My biggest advice…

Whenever you turn on a device, close a program, and just before turning off, go to Start>Settings>System>Memory>Running Programs to close all the programs running in the background. I just grabbed a Recon out of a drawer and checked and the following programs were running: ActiveSync, Internet Explorer, Wireless Manager, and File Explorer. Knowing our computers, I am surprised ‘Solitaire’ wasn’t running as well…

Finally, if you are using ActiveSync to send files back and forth, I recommend logging on as a “Guest” so you are not committed to a dedicated PC for file sharing.

I’ve written several times about COM ports and GPS receivers. Interestingly, in the last two days, I have spoken with four different folks about how this works, particular in regards to setting up a GPS receiver through a USB port on a tablet computer. It is valuable to understand how this works to avoid frustration in setting up software later.

What is a COM port?
A communication (COM) port streams data into the computer. Older computers had serial ports for this purpose. USB ports are not really COM ports, so you need to download a driver for the conversion. There are two facts about this process: you need a different driver for each different brand of GPS or other devices using the COM port, each USB port needs to be set-up as a COM port and each will be given a different port number. This COM port number will be used in any software that needs to connect to the GPS. (As a side note, you will also need to know the speed of the data stream from the GPS called the Baud rate.)

Setting up a COM port for an SX Blue II Sub-Meter GPS
The first step is to download the driver. I can’t post folders in the blog, but I put the driver on the Walcott Scientific website. This will comprise a folder with various .dll, security catalog, etc., files for the FTBI driver. The folder is zipped, so you need to unzip it. Then, place the folder somewhere you can find it, like the desktop. Now, power up the SX Blue II and plug it into the USB port you wish to use. The computer will open the “Found New Hardware Wizard.” No need for the internet, so click “No, not this time” and click “Next.” Then, choose “Install from a list or specific location (Advanced)” and “Next.” On this page, choose “Search for the best driver in these locations” and “Include this location in the search:” Use the Browse button to find the folder and click “OK” and “Next.” A warning box will appear that the USB Serial Converter has not passed the test. Click “Continue Anyway.” The driver is now installed and you will close the Wizard. But wait! Another Wizard will open and you will repeat the process. You’ve done it!

Finding the COM port
So, what is the COM port? You can use a ‘port sniffer’ like GPS Viewer which works pretty well for finding GPS devices. Alternatively, you can go to: Control Panel>Administrative Tools>Computer Management>Device Manager and click on the “Ports (COM & LPT)” to see the port number assigned to the SX Blue. This is the COM port you will use in your software. The SX Blue broadcasts at 9600 Baud, 8 stop bits, no parity.

I had an interesting case this past week that while unique, might shed light on some problems. A researcher has been using a CompactFlash GPS card in a Recon handheld computer without problems for nearly a year now. He e-mailed me that the GPS was working, but was coming in on a different COM port. Well….that can’t happen! COM ports, or Communication Ports are the electronic version of docks. They allow for data to be exchanged and, like a real dock, only one ‘vehicle’ can be there at a time. All computers use COM ports. Some have designated COM port numbers but allow you to create virtual COM ports. On a PC, it is typical for a serial port or an SD slot to have a unique COM port. If you have an integrated GPS that has a designated COM port. Because USB ports are wired differently, they require a driver to convert them to COM ports. Once a port is identified as a COM port, it stays a COM port. That is, the numbers don’t shift! On the Recon, the serial port is always COM1, the CompactFlash (either slot) is COM2, and Bluetooth devices come in on either COM8 or COM9. In the case of the “Mystery of the Shifting COM Port”, the CompactFlash jumped from COM2 to COM3.

Knowing the COM port for a GPS is necessary to run any software to read the data stream coming from the GPS. Unfortunately, the program I wrote for the researcher was set for COM2 so he could not use COM3. (As a quick fix, I re-wrote the program for COM3, but that didn’t address why the port should change.) Many programs allow you to figure out which COM port the GPS is connected to before you begin to collect data.

Back to the mystery, there are three scenarios: 1) The GPS tortured the computer into shifting COM ports, 2) there was a hardware malfunction in the computer, or 3) there was a gremlin in the operating system of the Recon. GPS receivers don’t have the capability to shift COM ports so that was ruled out. I was hoping the computer didn’t fail because the researcher was in the field in South Africa. So, I settled on the operating system. His Recon has Windows Mobile 5 which has a cool applet that allows you to re-route the GPS from its incoming hardware COM port (in this case, COM 2) to any outgoing COM port. The benefit is that many programs can read a virtual COM port. The analogy is that you phone can only take one call, but many receivers in your house can listen in. We tried changing the parameters on the GPS applet but that didn’t work. Dang. It seemed the most likely scenario (and the cheapest) was that the operating system flaked out. With Recons, it is really easy to restore the operating system. You do a hard reset by holding down the power button for a few seconds. When the yelp of a rapid double beep occurs, simultaneously press the flying windows and enter buttons. This will restore the factory settings. Of course the factory didn’t put on any extra programs or data so if you try this yourself, BACK UP ANY FILES OR PROGRAMS YOU INSTALLED!!

The result? One e-mail later, the researcher restore the factory settings and the CompactFlash GPS is back on COM2. The “Mystery of the Shifting COM Port” is closed. The lesson is, if it seems like the operating system is tweaked, return to the factory settings before you toss the computer. Oh, and back up the files!

Recently, ABC put out a news snippet about the “child killing” inaccuracies of GPS vehicle navigation units. Glossing over the semantically misleading title, the report did a decent job of quickly summarizing the obvious—navigational software is prone to errors. It is not that the receivers are inaccurate, but rather the GIS programming behind the directional software is not foolproof. Having driven sub-par vehicles all my life, I am well cautioned to not blindly trust ‘foolproof’ gauges like gas meters, speedometers, turn signal indicators, etc. I do trust billowing white steam as a statistically likely indicator that my car is overheating. So, where is the fault with the navigational systems and what can you do to lighten your chances of becoming a GPS child killer?

The various driving programs packaged by TomTom, Magellan, Garmin, DeLorme, and others, rely on a base map of roads. Already, there is going to be a spread of accuracy based on the detail of the map and the age of the data. Roads change; in some areas, a map can be outdated within a year. I live on a street that dead-ends against a creek and then shows up on the other side with the same name. It is not uncommon for folks to knock on our door wondering where the rest of the street lies. Some software allows for upgrades but it is up to you to stay on top of things. And, it is unlikely that daily, weekly, or monthly closures will appear. Secondly, in the better mapping packages, the roads are ‘weighted’ for traffic speed and other flow parameters. That way, you can mathematically deduce which is the best route even if it is not the shortest. We all know how this works whenever we try to explain to a friend or spouse that our way is “better.” Herein lies the problem. How many software packages are going to be more accurate than your knowledge, experience, and intuition for your neighborhood? Then why do you trust it for other neighborhoods you have never been to?

I blame the problem for the accidents and lost drivers on losing our ability to read a map and growing up in an increasingly virtual world. At some point in the Late Atarian, we evolved into a race that trusts virtual landscapes more than what is outside our window. Or, we just would rather inhabit that space. Why else would so many minivans and airplanes have TV sets instead of looking out the blessed window?

At this point, you may be wondering why I am writing about this on a fieldwork blog. Do you think the software for backcountry work doesn’t suffer the same shortcomings? In future blogs, I would like to explore how to improve the software we use for monitoring and recording our field work.

In the last blog, I gave an introduction to dilution of precision or DOP and explained when you need to know it and when you don’t. This time, I want to show you a very cool, free program to calculate your DOP values throughout the day. All you need to know is your latitude and longitude and day. The program is called “Planning” and is from Trimble. You can download it here.

To use this program, you need to first enter your position through File > Station. You can use the map feature to get ‘close’ but you really should use the correct latitude and longitude. On this screen, you also set the date and time and duration of observation. Then, you need the satellite almanac information. This is downloaded from the Trimble site as an ‘.alm’ file or you can use an ‘.ssf’ file.

Here we see a plot that shows the total DOP at 10 minute intervals for San Diego (where it is very lovely right now). Looks like 7:30 a.m. is the time to work.

That’s it! Now, play around with the different map features, it is surprisingly easy to navigate. Notice that you can use GPS (United States system) or Glonass (Russian system). WAAS is available but since those satellites don’t affect the DOP, they are not included in the almanac.

This cool screenshot shows the visibility of each satellite throughout the time period. You can turn satellites off and on to clean up the graph.

But wait…if the DOP is based on satellite positions, what happens if you cannot see a particular satellite because of mountains or buildings? Obviously, that satellite is no longer used in calculating the DOP. The “Planning” software doesn’t directly allow you to blank out areas of the sky (but you can turn off certain satellites). However, there is another great program that allows you to show the blocked view based on topography. Stay tuned…

Recently, I ran into an old professor of mine and we chatted about the use of computers in field geology. Both of us were trained using little more than compasses, 1:24,000 topographic maps and aerial photo interpretation. And we both agreed that students need to be trained in these methods. “So,” he asked me, “when do you decide to spend several thousands of dollars for good field computers?”

The answer I gave is that you bring a computer in the field if you need data handy. Data to read in the field or data to collect in the field. There is a real advantage to processing data in the field so you can shift priorities as you are working. Of course we are always collecting data, but not all data needs to be digested with a computer processor. One advantage I have seen recently is recording repetitive data. If you use a database program with drop-down lists, you are less likely to incorporate spelling errors and you can have the program prompt you for data so you won’t miss key features.

It is also standard these days to use a GPS receiver to locate key locations, but it is not as common to use the devises to track lines or areas. However, with a good receiver, you can often track your moving position directly onto a digitized map, saving time later.

Sounds great, but what is the catch? The obvious answers are that field computers are costly, take up space and add weight, and are totally useless if the battery dies. A less obvious answer is that we run the risk of creating a virtual ideal, even when we are outdoors. I have seen students rely directly on GPS receivers even when the receiver shows them in a gulley when they are standing on a ridge! Or you turn the world into a binary playing field when we know reality is probably more fuzzy.

The bottom line is that field computers and GPS receivers are fantastic tools, but we still need to teach the underlying fundamentals of location and data collection and interpretation. In future blogs, I will outline specific research and teaching projects I have done to illustrate successes with field computers—successes that justify the cost of bringing these tools in the field.

When you buy a Garmin or a Magellan, you are getting a computer + GPS receiver + software. Ready to go! However, if you choose to use a rugged PDA and attach a GPS receiver, you will need some sort of software to read the data and / or store the data and / or plot the data on a map. Today, I will mention two of the many freeware options out there that I actually use and recommend.

There are several add-on features to note when comparing GPS programs, whether freeware or purchased: 1) display position on a map, 2) store individual locations, 3) store tracks, and 4) display other information from the GPS receiver such as the accuracy or location of satellites. In addition, you should also be clear on how the data is stored. Unfortunately, most software stores the data in proprietary format. Fortunately, there are many programs available to convert these formats to a more usable format (such as GPS Babel). So, when you are comparing programs, keep in mind your needs.

The two programs I recommend are GPS Viewer and VisualGPSce (both available from the Walcott Scientific resources website). Neither can store waypoints or tracks or upload background maps. GPS Viewer is a good, simple program to check to see if your GPS receiver is working, and get a location and information on the quality of the signal [dilution of precision (DOP) and percent dilution of position (PDOP)]. In the opening screen, you can scan your device’s COM ports to find the GPS receiver.

Then, you can begin receiving data and follow the data as a stream. Toggling to the other screen shows a map of the satellites, the date and time, latitude, longitude, DOP, and PDOP. Again, I use this program to warm up my GPS receivers and test them. Remember to turn the program off if switching to another program or the COM port will remain in use!

VisualGPSce is a wonderful program that adds much more options, such as a navigation screen and a statistics screen that shows you the standard deviations of your data points. Also, you can save the NMEA codes as a text file if you want the raw format.

Unless I am mapping, these two programs suffice to allow me to use a GPS receiver and test the quality of the data. Neither program takes up much memory or requires a steep learning curve.