GeoExplorer 6000 Review (Part 1 - Canopy Challenge)

TweetThe internet tends to be a place of 'ADD' and short-lived attention spans when it comes to readers looking at content (trust me, I'm guilty).  That's why I'm deciding to publish my review of the new GeoExplorer® 6000 into four parts.  Tiny bite size pieces are the way to go, given today's hustle and bustle.Welcome to part 1.  On a cold snowy morning some few weeks ago, I took my GeoExplorer® 6000 loaner (from Seiler Instruments) out to meet Tim Smith, the National Park Service's GPS Program Coordinator.  If anyone knows about GPS under canopy, it's this guy.  Around a foot of snow had fallen overnight in beautiful Conifer, Colorado helping to load up the evergreen trees around our GPS test course.  The loaded canopy can be a  GPS unit's worst nightmare.  I thought to myself, "This was exactly how I'd like to put this unit through it's paces".  We occupied a total of three monuments.  All of them were shot in with a survey-grade total station.  The horizontal and vertical coordinates were of very high accuracy. Besides the GeoExplorer®, we hooked up a Zephyr antenna, and dialed in to the Trimble® VRSNow™ service.   VRSNow™ Coverage USAFor those of you who aren't familiar with VRSNow™, it's an ever growing GPS correction service that utilizes a network of GPS Base Stations around the world.  The stations are owned and operated by Trimble® and select Trimble® Partners.   Whilst this is not the first GeoExplorer® to support real-time VRS™ technology, this is the fist GeoExplorer® to ever have the option for a built-in modem.  This allowed for easy access to the VRS™ corrections without the need of a separate phone or modem.I'm lucky enough to have the Colorado VRSNow™ network in my backyard, so you bet I'm going to tap into those corrections!  This test under canopy will also not only put the GeoExplorer® 6000 to the test, but also put the VRSNow™ network to the test.  In addition to the standard survey-corrections, the network outputs a stream just for GIS corrections called H-Star™, which is priced way cheaper than survey corrections.  Our testing on this day was actually outside of the network, with the closest GPS Base Station being in Waterton Canyon (see map below). Thus, the solution that we were getting was extrapolated vs an interpolated network solution.  We sat on each monument for around 180 positions (@ 1 position/second).  Points 3 and 4 (see map) were probably the hardest as they were deep under canopy.  The GeoExplorer® performed flawlessly.  Clicking on one of the icons in the map will yield a report.  2D (horizontal) accuracy is stated on the datasheet at decimeter.  But I don't live in a 2D world.  I wanted to see 3D accuracy.  So the graphs and reports that I've tabulated for this exercise show 3D displacements in space from observed positions to the known survey monument.   If you click on one of the icons in the Google Earth pane below, you will see the 3D displacements.  Give the map around 20 Seconds to load the dataGive the map around 20 Seconds to load the data |View NPS Test in a larger mapIf you want a better view of the 3D displacement data, you can look at the links below.  The pretty yellow, green, and red graphics are actual shots of the points in space with site lines connected to the monument.  Keep in mind that this was under heavy canopy.  Also keep in mind that the pictures below might look like a huge fountain of positions, when in reality all are well under the total length of a standard no.2 pencil (~18 cm).Point 3Point 4Point BBelow is a spreadsheet reporting the displacements for the features that were averaged from the positions.  I'd say that the GeoExplorer® 6000 performs pretty good under canopy.  What do you think?Are you mad that I'm not showing post-processed results?  It's not my job as a blogger to make friends. :-p  Occasionally, I'll have to drag you kicking and screaming into the future.  It's time to hop on the real-time train my friend.  This is where Mobile GIS is headed.  Post-processed results are accurate, but only on a map.  When you go back out in the field, you are back to Autonomous GPS, SBAS with line-of-site, or NDGPS with a beacon (other options do exist).  Try explaining how your 'post-processed mapped' curb stop shut-off valve could not be found in real-time during a critical situation involving busted pipes, six feet of snow, wee hours of the night, and a seriously unhappy on-call field crew.  In the world of real-time accuracy, there is no issue.  As always, If I got something wrong, or if you would like to add to the conversation, please comment!  Much thanks to Tim Smith, Eric Bock, Jay Riester, Lanny Schnipper, and Joseph from the Trimble Support crew for all of your help.   Believe it or not, you all helped in some form or fashion with this post.Stay tuned for part 2 of my review.  I'll cover in-depth how the GeoExplorer® 6000 performed in the urban canyons of Downtown  Denver.  -CheersAlex MahrouGeoExplorer, VRSNow, VRS, H-Star, & Trimble are Trademarks of Trimble Navigation Ltd.