Lost Over The Pacific

Here’s a great story published today on the GPS World website about what happens when an aircraft loses all electrical power and ‘goes dark’, leaving the crew unsure of their position on a long over water flight. The navigator’s solution? Pull out the airplane’s bubble sextant and start taking readings to calculate a line of position!

GPS World

(Just click on the image to open the article)

Based on the author’s description of the event and his mention that the GPS equipment racks were in-place but the units were not yet installed I’m guessing this incident occurred sometime in the very late 1980’s or early 1990’s. It’s a fascinating tale of how old analogue equipment and basic navigation skills, mixed with a little educated guesswork based on experience, can save the day.

Think this same thing can’t happen today? Think again. Modern aircraft are little more than computers with wings, and the number of points of failure on these ‘systems’ are exponentially greater than older aircraft. Not only can a modern aircraft experience a complete loss of power, it will happen at some point. It’s all a matter of odds. When the odds are against you the electrons will stop flowing. Then what?

The author interestingly contrasts this experience with what would likely happen today. Crew members would pull out handheld GPS units or smartphones and the plane would safely navigate to its destination with little drama beyond an ass-chewing for the maintenance team and some great bar room “There we were at angels 20…!” stories. But like modern aircraft, GPS receivers and smart phones require electricity to run. Let’s hope everybody charges up before boarding the airplane!


Something Interesting From Trimble

I’ve been expecting one (or more) of the major survey & GIS data collector manufacturers to come out with something like this for some time now. I’m not surprised that Trimble was first out the gate. It’s called the Trimble Leap.

Trimble Leap

If you understand what’s going on with this new product you realize it’s a fascinating concept. It’s not just a small GPS receiver mated to a smartphone via Bluetooth – that capability has been available for a few years now. What this receiver provides is more advanced GPS signal tracking and the integration of Trimble’s RTX GPS data correction service. Trimble’s RTX service is a virtual reference station (VRS) system that receives GPS data corrections using the smartphones’s cellular data connection. This allows the Leap receiver to provide on-the-fly GPS positional accuracies that are less than 1 meter. Remember sports fans, the best your smartphone or Garmin Nuvi can do is about 15 feet, and that’s on a good day, under open skies, with lots of GPS satellites available.

Keep in mind that the Leap is not a survey grade device. It’s a lower precision field data collection device. The kind of thing a utility company would send a work crew out with to collect manhole locations. For applications like utility data collection, sub-meter accuracy is just fine.

The Leap concept is the next evolutionary step to take smartphones into the high accuracy/precision GIS data collection role. Smarphones are really just small computers with built-in modems, so they are the ideal computing platform for applications like this. However, smartphones have one huge Achilles heel – battery life. An ‘always on’ Bluetooth connection and cellular data connection will suck a smartphone battery dry in just a few hours. This is not a Trimble issue, but something that must be taken into consideration when putting devices like these into the field to collect a day’s worth of data. Better make darned sure you’ve got that in-car phone charger along with you!

There are still a lot of unknowns with regards to the capabilities of this system. Is the Leap receiver GLONASS capable? Does it allow data collection without the RTX connection? What about cost? I’ve read reports that the Leap hardware will run just under $1,000 and the RTX data correction service will be an additional $400/year per device. If you have any understanding of how much RTK compatible GPS receivers cost, and how much a VRS data service costs you will realize that $1,000 for the hardware and $400/year for the data service is a bargain.

Where I think Trimble stumbles is that they have slaved the Leap to their Terrain Navigator Pro (TNP) software. My impression is that TNP is a moribund product and Trimble is trying to breath some life into it by slaving it to a very capable hardware package. My hope is that Trimble quickly migrates the Leap software interface to other products like its own TerraFlex cloud service and even develops a plug-in that allows Leap data streams to be read by products like ArcGIS Online mobile applications.

– Brian

Some GNSS Musings

First things first – GNSS is the new GPS.  Actually, GPS is a subset of GNSS. GPS stands for Global Positioning System, GNSS stands for Global Navigational Satellite System. For decades folks refereed to any and all satellite navigation systems as GPS, and for good reason – the US Global Positioning Satellite system was the only game in town. However, the term ‘GPS’ properly describes just the global positioning system established and maintained by the United States. Now that the Russian GLONASS system is operational, and systems from the European Union, China and perhaps other players (India?) are coming on-line, the term for ALL space-based satellite navigation systems has shifted to GNSS.

OK, now that that’s out of the way.

I spent the last two days in training finally learning how to run Trimble’s TerraSync and Pathfinder Office software.  We’ve had TerraSync and Pathfinder Office software in our office for years, but never got any formal training on how to use either package.  The training was actually very good, and I can see now why a lot of surveying and engineering firms prefer TerraSync over GIS-centric packages like ESRI’s ArcPad.

The class was taught by one of the training and support personnel from our local vendor, NEI, and he did a great job.  Woven throughout the class are discussions about GPS, datums, coordinate systems and issues like unanticipated coordinate system shifts due to improper datum selection or datum mis-matches between the software and virtual reference station (VRS) datums.  We spent a good deal of time in the field actually experiencing the impact of changing datum selections in the software (for example, the shift seen when selecting NAD83 vs. NAD83 HARN).

So this class got me thinking again about GNSS and data quality and accuracy…

In the olden days, like before the turn of the century, these datum shifts generally didn’t concern GIS folks.  The shifts introduced by any datum mis-match were well within most folk’s error budgets.  In most cases we were ecstatic when GPS got us within a few dozen feet of the features we were collecting.  When the accuracy standard of the 1:50,000 topographic map you were using as a base was +/- 50 meters having GPS points a dozen or so feet off was no big deal.  In fact, we were tickled pink to be able to get that level of autonomous GPS accuracy.

Today things are much different. Improved GNSS software, antenna designs, the open availability of reliable GPS and GLONASS signals and the wide availability of GPS augmentation services like WAAS and local virtual reference stations (VRS) means that these systems are capable of sub-meter, often sub-foot, accuracies. That’s just for GIS data collection.  Survey-grade GNSS systems are capable of real-time accuracies to tenths of a foot. Suddenly datum shift errors of even one foot become very, very important for high precision data collection and surveying.

One of the biggest problems people in my line of work face is a general lack of understanding of GNSS in the GIS and civil engineering fields. In particular, many professionals lack up-to-date training and working knowledge of GNSS system capabilities, limitations and application to their line of work.  Evaluating and planning for the potential impact of things like datum shift on GNSS-based surveys or data collection projects is something they can’t comprehend largely because they haven’t been trained on it and, perhaps most important, have’t been forced to consider it when planning or managing a project.

Sadly, I’ve met far too many people with a GISP certificate hanging on their wall who couldn’t tell me the fundamental difference between the NAD 27 and NAD 83 datums, and I have yet to meet a single civil engineer who is not also a licensed surveyor who could explain to me the importance of knowing the datum his or her CAD drawing coordinate system is based on.  Yet both of these groups – the GIS professional and the civil engineer – have a fundamental interest in controlling the overall accuracy and precision of their work.  For the GIS professional it’s a matter reputation and trust.  For the licensed civil engineer it could be a matter of putting his or her work at legal risk.

If you work in the GIS field you can not call yourself a GIS professional unless you have a fundamental understanding of datums, coordinate systems and the importance of applying this knowledge to your workflows.  A strong knowledge of datums and coordinate systems is one of the foundational building blocks of our profession, and since so much of what we do these days is GNSS-based it makes it equally important to have a strong understanding of the impact different datum selections can have on the spatial quality of our data.

I’ve said before in this blog that those GIS ‘professionals’ who consider GIS to be little more than making web maps are headed to extinction. Here in the Atlanta metro area it would take me about an hour to hire a busload of web developers who can make web maps (and this includes time out for a stop at Starbucks). If that bus accidentally rolls into the Chattahoochee River and everybody drowns I can get another busload just as fast. However, the number of GIS professionals I’ve run into who can tell me the anticipated shift in State Plane (NAD83) and State Plane (NAD83 HARN) coordinates wouldn’t fill the first row of that bus.

For the civil engineering community the issue is less obvious but just as critical. GNSS-based surveying and data collection is becoming the norm on many projects. It is faster, cheaper and just as accurate as conventional surveys under the right conditions. This means civil engineers will be incorporating more and more GNSS-based data into their designs and relying on GNSS for jobsite control, machine control and as-built data verification. While the task of establishing project control, setting up survey equipment configurations and managing project survey requirements will fall to the the project surveyor, the project engineer still has overall responsibility for ensuring things are built to design.  If the project stakeout is a few feet out from the design drawings it may not be because the instrument operator has a hangover; it may be because the design work was done in one datum and the GNSS survey unit is set to another. Being able to identify a potential datum shift problem is a key skill for civil engineers working in today’s GNSS-based world.

– Brian


Word just came out that yesterday the Russians accidentally set eight of their GLONASS (the Russian equivalent of GPS) satellite statuses to ‘unhealthy’ for about half an hour. Setting a satellite status to ‘unhealthy’ means the satellite is programmed to tell receivers to ignore the navigation signals it is broadcasting because there’s something wrong with the satellite and the signals can’t be trusted. Eight satellites constitutes over half of the GLONASS operational constellation. When this many satellites are set to ‘unhealthy’ it means that most advanced GNSS receivers will simply ignore the entire system and not even try to use their signals to calculate a position.

glonass satellite

This is not good news for the Russians, or for GLONASS users world-wide. (Got a smartphone? Then you are a GLONASS user whether you realize it or not). For years the GLONASS program has been plagued by corruption, poor management, poor planning, lack of funding and launch failures. The GLONASS program’s biggest problem has been money, or a lack of it. Global satellite navigation systems are frightfully expensive and require long-term capitalization and national committment. Only the United States with its NAVSTAR GPS system has been successful in establishing and maintaining a healthy world-wide space-based satellite navigation system for over 20 years. In Russia’s defense, at least they’ve been able to get a fully operational system up and running. The European Union has been stumbling around with their Galileo system for 15 years and so far about all they’ve been able to do is put a few test satellites in orbit.

As they say on TV, “but wait, there’s more!”  Back on April 1st the entire GLONASS system went wonky when bad ephemeris data was uploaded to the satellites. Ephemeris data is what allows each satellite to accurately locate itself while in orbit. Ephemeris data is updated regularly for all satellites in a system – it’s part of the routine system maintenance process. Well someone uploaded bad ephemeris data files to the entire GLONASS constellation and for 11 hours every satellite in the system was squawking bad navigation data. The Russians didn’t realize it until one of their commercial customers called to tell them their satellites were providing lousy location fixes.


Better keep those paper maps and magnetic compasses handy.

– Brian

GPS Proves Einstein!

Well, it verifies Einstein’s Theory of General Relativity.

Here’s a very interesting video of the 2012 Isaac Asimov Memorial Debate on whether neutrinos can travel faster than the speed of light.  One of my favorite scientists, Dr. Neil DeGrasse Tyson (the fellow whom Sheldon Cooper blamed for having Pluto downgraded from a planet to a mere ball of ice) does a great job of moderating and keeps the discussion both lively and understandable for public school graduates like me.

Part of the discussion focuses on Einstein’s Theories of Relativity, both Special and General.  The General Theory of Relativity states that time moves faster in low gravitational fields.  This is known as gravitational time dilation.  Starting about the 30 minute mark the discussion turns to how the atomic clocks on board the US Global Positioning System (GPS) satellites are intentionally ‘slowed’ to compensate for the changes in the progression of time in lowered gravitational fields. One of the panel members, Dr. Christopher Hegarty of the MITRE corporation, comments on how tests have shown that if the clocks on the GPS satellites are not intentionally slowed then the signal accuracy based on the uncompensated clock will drop from a few dozen feet to about 11 kilometers in just one day!

Dr. Hegarty also comments about how some of the time compensation computations are actually handled by the GPS receiver software.

So remember folks, every time you fire up your GPS (or even just use your smartphone to find the nearest Starbucks) you are helping to verify the Theory of General Relativity.  Go Einstein!

Garmin Gets Serious

I got a news release today that Garmin is about to release their first Android-based GPS receiver.  This is a move I long suspected one of the major GPS receiver manufacturers would make, and given Garmin’s market dominance and previous experience with Android I naturally assumed they would be first.

Garmin calls it the Monterra.  What is it?  Well, it’s essentially a smartphone without the phone.  An Android based GPS unit with a digital camera, LED flash, compass, barometer, gyro, accelerometer, Wi-Fi, Bluetooth, MicroSD card slot, etc.  About the same features you’d expect to find on a mid-high range smartphone.  Ho-hum.

But the Monterra offers some key differences.  First, it started life as a GPS receiver, designed by the world’s leader in consumer GPS technology.  This means the GPS performance and antenna design should have received priority consideration.  Next, it’s IPX7 compliant, which means it’s highly water resistant and shock resistant.  Third, it has user replaceable batteries.  Limited battery life is perhaps the single biggest argument against using a regular smartphone as a back-country GPS receiver.  With user replaceable batteries, and the use of standard AA cells, Garmin makes this a serious off-the-beaten path unit.  And last, it uses Android.  What, you ask?  Why is that important?  The adoption of Android as the OS opens the device to a whole range of outstanding GPS and mapping applications.  In fact, I’d go out on a limb and say that most users will load this thing up with third party apps and pay little attention to the included Garmin apps and map package offerings.

But my interest in the device focuses on its potential as a serious GIS data collection tool.  For the first time we have a rugged, water resistant Android-based GPS unit that should be able to run ESRI’s ArcGIS and Collector apps and Trimble’s new Terra-Flex app.  It offers all the hardware capability those apps need to leverage for effective data collection – good GPS performance, high resolution digital camera, a responsive high resolution touch screen and good battery life.  Once ESRI gets its act together and introduces data caching with their Android apps the lack of full-time data connectivity via a cellular data plan won’t be so important.  ESRI may well be there by the time this device is released (and Terra-Flex is already there).

I only have three concerns.  First, the relatively small 8 gigabyte system memory.  Second, Garmin has not announced what version of Android this will ship with.  Here’s hoping it’s at least 4.1.  And last, the price.  Garmin has initially priced this thing at $650.  When you consider an unlocked top end smartphone like the iPhone 5 or the Samsung Galaxy S4 goes for just a bit more, and the very capable Google Nexus 4 goes for way less, you begin to think this thing is somewhat over priced.  I’m hoping the retail pricing comes in a bit less.

Still, it has the potential to be a very price competitive and capable field data collection unit.  Is it about time to retire the old Juno?  We’ll see…

GPS – It’s Not Just For Geocachers!

OK folks, let’s put on our big boy pants and play grownup GPS.

“Look at me!  I know how to use GPS for
something other than geocaching!”
I’m involved in a test at a very large and very busy airport to determine the feasibility of using inexpensive handheld GPS receivers as reconnaissance tools for our engineering and facilities staff.  The consumer market is crammed with relatively inexpensive GPS devices and any one of those should fit the need.  We are not necessarily looking for accuracy here; most dedicated GPS units made these days offer plenty enough accuracy.  More important for our project is ease of use, the ability to import a fairly high resolution background image of the airport and the ability to provide coordinate read-outs in our proprietary (i.e., non-standard) grid system.
Let’s start with the proprietary grid system issue.  It may sound daunting, but it’s really not.  A fair number of low end GPS units provide what’s called a ‘user coordinate system’ setting.  The user just needs to provide a center point for the grid (in lat/long), a false northing and easting for the center point, a scale factor and few other bits of information.  It’s pretty straight forward, and we’ve been able to program a 13 year old Magellan 315 to handle the task.  The Magellan 315 was a hot-spit GPS unit in its day but by today’s standards it is out dated.  It is relatively slow to boot up, slow to acquire and lock onto satellites and it doesn’t receive WAAS signals.  Still, it is easy to operate, the screen is a classic example of uncluttered high contrast clarity and it takes user coordinate system definitions without breaking a sweat.  Once it was up and operating it provided perfectly acceptable accuracies.
Magellan 315
Simple to operate and
has no issues with operating under
a proprietary grid system
Next we tested a seven year old Thales Mobile Mapper.  The Mobile Mapper was a piece of kit left behind at the close of a project several years back.  The contractor bought it to help locate underground utility marker balls and turned it over to the airport when the contract ended.  It’s an odd duck piece of gear – not friendly enough to take on a fishing trip but not sophisticated enough to satisfy surveyors.  Still, it was perfectly willing to accept our coordinate system definition and returned fine accuracies.
Thales Mobile Mapper
So we proved it’s possible to program our coordinate system into inexpensive GPS units.  It should be a simple task to identify a more modern unit that fit our performance and budget requirements.  This is where things got interesting and frustrating.  Our quest has revealed an ignored market segment for GPS units and leaves us scratching our heads and wondering just where the consumer GPS market is heading.

GPS is marvelous technology.  It has removed the great uncertainty in wayfinding and positioning that has vexed mankind since the first caveman decided to go from here to there and his wife told him where to turn.  The real genius of GPS has been in the integration of the location signal (and that’s all GPS really is – a bunch of signals from satellites in the sky that provide the information a GPS receiver needs to calculate a position) into devices that leverage that location in unique ways.
Twenty years ago a ‘consumer grade’ GPS was an expensive piece of gear that did little more than provide a location and allowed you to store a few dozen waypoints.  In 1999 I purchased the Magellan 315 used in this test for $300, and was happy to get it at that price.  Today $300 buys a unit that provides a position fix that is twice a precise as the 315, uses a high resolution color touchscreen display, stores thousands of waypoints, has a digital 3-axis compass, a barometric altimeter and a digital camera that takes geotagged images.
But the success of the integration of dedicated GPS receivers is also proving to be their undoing.  Here’s why.  I can walk into just about any AT&T, Verizon, T-Mobile, Wal-Mart, Target or Best Buy and purchase a smartphone that offers these same features for about $200 (if I sign up for a service plan).  But in the package I also get a phone, a messaging device, a video chat device, an internet device, a music player, a game console and much more.  The integration of GPS into common consumer devices like phones and tablets is killing the dedicated GPS industry. It’s not that highly integrated devices like the iPhone are better GPS devices – far from it.  The real problem is perception.  When pondering the purchase of a dedicated GPS unit the average consumer glances at his or her smartphone and asks, “why spend another couple of hundred bucks when I already have GPS and a mapping application rolled up into this device?”

Most consumers are not educated enough to understand that a dedicated GPS unit offers features that make it uniquely suited to outdoor use in rugged environments.  GPS integration in a smartphone is a compromise, particularly the antenna system.  On a smartphone GPS has to coexist with a range of other receivers and transmitters that all require their own antennas – cell, wi-fi, Bluetooth, etc.  A smartphone is first a phone, and other features like GPS get secondary design consideration.  But with a dedicated GPS unit optimized GPS reception and performance is the primary design goal.  First and foremost we expect a GPS unit to provide fast and accurate position fixes under a wide range of conditions.  If you want to know where to find the nearest Starbucks get a smartphone.  If you are on a seven day backpacking trip and its been raining the last three days and you want to know where the next campsite with a bear box is located get a dedicated GPS.

So let’s take a closer look at how the market is broken down.

Today’s dedicated GPS devices fall into three broad categories.
1. Consumer grade devices like we are discussing here.  This market is focused mainly on those participating in outdoor sports like geocaching, hiking, biking, fishing, etc.  These devices cost between $200 and $700, with the bulk of sales taking place at around the $300 price point.  This is the market segment that receives brutal competition from other consumer devices like smart phones, and the manufacturers are scrambling to find a niche and stay relevant.  Garmin, Magellan and DeLorme are the three leaders here.
The Garmin eTrex is perhaps the most
successful line of consumer GPS units in the industry
2. Dedicated map data or field data collection devices.  These are handheld units running mapping software like ESRI’s ArcPad and are used by organizations like utility companies to collect information in the field.  These mapping devices have an entry price point of around $1,000 and can go up to over $3,000.  Most of these units offer more GPS accuracy through the use of improved antennas and better software, but offer fewer features like digital compasses and altimeters.  The big attraction with these GPS units is the flexibility of the mapping software and the ability to directly ingest the collected data into high end desktop mapping software like ESRI’s ArcGIS suite.  The additional cost for these dedicated GPS units is the result of a smaller market share, higher hardware costs and the increased cost of the the operating system (usually Windows Mobile) and the mapping software.  Trimble Navigation dominates in this market.
Trimble Juno
No compass, no altimeter but hey,
at least it runs Windows!

3. The high end market is dominated by survey-grade GPS units that start around $5,000 and can peak out at over $30,000.  For that price (along with a subscription to a real-time correction service that runs a few thousand each year) the user gets accuracies on the order of a few centimeters horizontally and vertically while working on-the-fly.  Not for the casual user, but it is interesting to note just how much accuracy thirty grand can buy.

A GPS-based surveying system.  This unit is capable of accuracies
of +/- 4 cm within 5 seconds of being placed over a point.
How big is 4 cm?  About the size of a poker chip.
Not for the faint of heart, though.  The saucer-shaped thing at the
top of the pole (Trimble R8) is the high accuracy
GPS receiver and it alone costs about $8,000
OK, back to our original topic.
The goal is to find a GPS receiver that:
a. comes in at around the $250 – $300 price point
b. can use our custom coordinate system
c. can use a high resolution aerial imagery as a background map
d. is easy to use – should be almost a ‘grab-n-go’ device
e. collects simple data points, lines or polygons in a format we can easily bring in to our GIS and CAD systems

We selected a fair number of units to test – the Magellan 315 and Thales MobileMapper mentioned earlier, a Trimble Juno and Yuma, a Magellan eXplorist 610, a DeLorme PN-60 and a Garmin eTrex 20.

Top – Trimble Yuma
Middle – DeLorme PN-60, Thales MobileMapper, Magellan 315
Bottom – Magellan eXplorist 610, Trimble Juno, Trimble TSC-2

The DeLorme and the eTrex quickly fell out of the competition.  The DeLorme does not support user coordinate systems (a very disappointing shortcoming in an otherwise outstanding GPS unit).  The eTrex does have a user coordinate system setting, but it only works in meters (our custom airport coordinate system is set up in feet).  I was really pulling for the eTrex 20 because it’s the cheapest of our test samples ($175 Amazon price), has a good screen, an intuitive menu system and its receiver tracks both the US GPS and the Russian GLONASS satellites.  Alas, Garmin tech support could never figure out how to get it to provide readouts in feet so back to the store it went.

The Trimble Yuma is really a tablet computer running Windows 7.  It is a very capable device, but at the $5,000 price point falls way outside of our test objectives.

The Trimble Juno is an interesting unit.  It is essentially a highly customized PDA that runs Windows Mobile 6.1.  This Juno is really the lowest entry point in terms of price and features for a serious handheld GPS mapping and field data collection device.  Unfortunately the entry price is still too steep for this test – the hardware itself costs around $1,000 and the software needed to do field reconnaissance and data collection – ESRI’s ArcPad – runs an additional $400.  A good device, just too expensive and too complex for the non-technical user.

The Trimble TSC-2 seen in the picture above is not really a GPS receiver.  It is a survey-grade data collector that pairs with a high precision GPS receiver via Bluetooth (we use a Trimble R8) .  I threw it into the picture just for comparison.

The Magellan 610 pulled ahead early in the competition.  It’s a mid-sized unit that’s a bit chunky but fits well in the hand.  It uses a touch screen interface and it includes a 3.2 mp camera that geotags each image.  After some fiddling it took our custom coordinate system and returns very good accuracies on the order of +/- 10 ft.   I should mention that a large airport is an ideal location to test potential GPS accuracy since you have open skies horizon-to-horizon.  If the GPS satellite is above the horizon your receiver will see it.  No trees, buildings, towers, etc. in the way.  So please, don’t take my accuracy results as gospel.  Your real world results will vary.

Magellan eXplorist 610
A very capable little device

Where the Magellan 610 stumbles is ease of use.  It has a lot of features – GPS, camera, compass, barometer and altimeter.  It is a jack of all trades and, to be honest, most features are fairly well integrated.  However, learning to use them takes time and it’s easy to get lost in the touchscreen menu system.  The Magellan also suffers from a disease that afflicts most other consumer grade handheld GPS units – ‘gamesmanship’.  In an effort to attract new customers manufacturers like Magellan, Garmin and DeLorme have built their user interfaces around the game or sport of geocaching.  It’s a fun game and a great way to get tech savvy kids off their asses and into the outdoors.  The low end GPS manufacturers see this as a market niche they can exploit and have structured most of their unit’s features around geocaching.

The problem we face is that geocaching-oriented GPS units makes lousy general purpose or field data collection units.  By focusing on geocaching the manufacturers have ignored the needs of a whole different market segment – the map data developer.

A weak coordinate system library, the lack of a GIS-industry standard vector data format such as the ESRI shapefile, weak data attribution tools on the GPS unit and a weak desktop mapping interface all hinder the use of these units as data collectors.  DeLorme comes the closest with it’s XMap desktop GIS software, but the cost is over $800 per license it continues to use a proprietary vector data format linked back to the PN-series receivers.

What the industry needs is a low-end map data collector that has a simplified interface optimized for adding and attributing data collected in the field.  It needs to use industry standard vector and raster data formats and should come with a more robust desktop mapping interface oriented towards the field mapping industry or enthusiast.  Magellan seems to be dipping its big toe back into this market with the Magellan eXplorist Pro 10, but this device still requires a third party software package like ArcPad and offers no improved desktop mapping software.

Magellan eXplorist Pro 10
This is just a re-packaged Magellan 610, but a good start!

So GIS industry wonks, here’s what I want:

1. a handheld GPS unit with a large, high resolution screen that is easy to read in broad daylight

2. consumer-grade accuracy using WAAS correction

3. a user interface highly optimized for field data collection – no third party software requirements!

4. a robust horizontal and vertical coordinate system library and the ability to accurately define a user coordinate system

5. a 5 megapixel digital camera with flash

6. the ability to configure field collection jobs or scenarios and save them as project files

7. twelve hour continuous use battery life

8. an external antenna port

9. fully waterproof

10. improved desktop software for device configuration and data download and upload

11. use of industry standard vector and raster data formats

And I want this all at a $700 retail price point.

So get to work.  I expect some nice surprises in your 2013 lineups!

– Brian


I’ll make this quick.

I’m deep into preparing a briefing/presentation/class on the issue of magnetic declination and the easiest rules to follow when you need to apply it.

What’s magnetic declination, you ask?  Sorry, that’s not the topic of today’s post.  If you really – REALLY – need more information right now check out the Wikipedia page on Magnetic Declination.  I’ll be referring to it in a later post.

Anyway…  I was mentioning to a friend that I was working on this presentation and he commented “Does anyone really care about that anymore?  I think everyone has just gone out and bought a GPS.”

I actually get that reaction a lot when I talk to people about compasses and using a map and compass to navigate.  “Compasses confuse me.  I’d rather just use a GPS” seems to be the common refrain.

(For the uninitiated, GPS stands for Global Positioning System, or space-based satellite navigation system.  There are several operational (US, Russian) and developing (the European Union’s Galileo) satellite navigation systems, but ‘GPS’ has become an almost a generic term used to describe the US developed and operated NAVSTAR system.)

I live and work in the world of GPS.  I’m a geospatial professional and I run the GPS-based survey and data collection program at the World’s Busiest Airport.  Every day I am thinking about, using, training, developing policies on and attending meetings about GPS and how we use it at our airport.  Everything from upgrading our high-precision GPS receivers to providing airport-specific input for the FAAs GPS-based NextGen precision approach program to review and quality control of project layouts generated using GPS-based survey systems.  And more.

I am the biggest cheerleader for the GPS system and GPS-based technologies.  GPS is perhaps the best example of a project that only the United States could do, and do right.  The driver who switches on his Garmin Nuvi for the drive to the airport is leveraging tens of billions of dollars and decades of research, development, testing, deployment, maintenance and upgrades.  All paid for by the US taxpayer, and all free to any user anywhere in the world.

Conceptually the GPS system is simple – satellites in space broadcast their position and your receiver (example – our driver’s Garmin Nuvi) uses time shift calculations to determine the precise distance from your location back to the satellite.  Once the receiver picks up and processes signals from at least two more satellites it can triangulate your position.  The size of the position ‘triangle’ determines the accuracy of the position fix provided by the receiver, but in general a modern receiver tracking three or more good satellite signals can locate you to within about 15 feet of your true position anywhere on earth.  That’s pretty damned good by anybody’s reckoning.

GPS has revolutionized many industries and spawned completely new ones.  GPS systems are so pervasive that most people no longer give them a second thought.  Today GPS technology tracks your package as it travels from the retailer to your door, and it tracks the paroled felon sporting the nifty ankle bracelet.  GPS technology manages the hand-off of your phone conversation from one cell tower to another as you speed down the interstate, and GPS technology guides the angle of the bulldozer blade working a local road construction project.  Anything that locates you on a map is universally identified as ‘GPS’, even if the function has nothing to do with satellite-based navigation.  GPS has become an integral part of our lives and impacts us for the better every day.

And yet, GPS is a system with serious limitations.  It can’t locate you indoors, in tunnels, under overpasses, in dense forests or even in the man made canyons of large cities.  The signals can be easily corrupted, blocked or bounced around so much they are virtually useless.  The entire GPS system is a delicate balance of high technology and rocket science, enormously expensive to maintain and upgrade.  At some point the GPS system – certainly a system that succeeds what we have now – will fail.  It will fail due to funding shortfalls, political upheaval, changing national priorities or simple neglect.  This failure is merely a recognition of a historical inevitability – man made systems always fail at some point.

Long after the GPS satellites go cold and dark in their far orbits and GPS receivers become little more than technological oddities, the magnetic compass will continue to offer reliable wayfinding.  Using a compass (along with a map) is not easy or intuitive for most people, but once learned it provides a reasonably accurate, reliable, steady and ‘always on’ navigation capability that can not be turned off by man’s whim or neglect.  I feel fairly certain that at some time in mankind’s future we’ll be back to navigating using the simple, reliable magnetic compass.  It’s inevitable.

That’s why I still practice my map and compass skills.