Workforce for ArcGIS is one of Esri's native GIS applications that allows you to take advantage of a streamlined work order management system that is built directly on top of your GIS platform. This tutorial provides a basic overview of the application both from the desktop browser as well as a mobile perspective. For more information on how your organization can integrate work order management with GIS
Earlier in my life, I never ran. I mean from bears, sure, probably I would have. I occasionally played a round-ball-type sport that required moving arms or legs quickly. If I had to actually run, I hated every second and would never consider running for health. Well, circumstances change and different things matter as you approach mid-life. Two years ago I found...
If you have ever been involved with a GIS project that requires data collection using a handheld device there is no doubt that you at some point ask yourself "Is this spatially accurate enough?". Well here is some evidence that proves those little tiny GPS chips within those smart phones are actually pretty good.
We wanted to get some numbers for this idea so we took five different mobile devices (listed below) and tested their GPS accuracy against a known control point (NGS Point ID: DF4314). Our chosen devices were:
- iPad 4th Gen (16GB WiFi + LTE)
- iPhone 4S (3G)
- Motorola Droid Razr Maxx
- Garmin Colorado 300
- Trimble Geo XH 6000
What we discovered was somewhat surprising. As you can see from the list these devices vary in use from the simple smart phone for GPS navigation & driving directions, to the professional series Trimble Geo capable of providing survey grade GPS positioning. Below is a map showing the different precision & accuracy for each device in relation to the benchmark. We stood over the known control point and collected five GPS points with each device and averaged them and found the following observations as a result:
- When it comes to accuracy, you get what you pay for as it was no surprise that the Trimble unit provided the greatest accuracy when used with real time corrections.
- Most of the devices, such as the Motorola, had good precision but lacked in accuracy.
- All devices, except for the Trimble, missed the mark in the northwest direction.
- The uncorrected data from the Trimble provided very high precision but low accuracy.
- The iPhone was all over the place on its readings but came within 4 feet of the target when the points were averaged (that's outstanding!)
- In general, the iOS devices outperforms all of the competition when averaged except for the professional grade systems
So what does all of this show us? It proves that you still have to pay big dollars (+$10k) to get a "high accuracy" GPS device but you can make an awfully strong case for a $600 iPad with the right data collection app. Who knows, maybe the day of "survey grade" accuracy in a smartphone is in the very near future.
A pile of GPS mobile devices sitting atop our known control point.
Avoiding the shock of the fence and the charge of the bull....
So how do you get a highly accurate GPS location on something that is not accessible??? Using the Trimble Geo XH 6000 series and Terrasync (cm) Edition we are able to use the "Offset" command in the Data collection tools within Terrasync software. We simply tell the unit that the point is exactly 10 feet south of our current location and we start collecting data. The system will automatically assign the GPS location with an offset of the given distance and bearing. Out in the woods and not sure on the bearing??? Simply pull out your iphone and use a compass app to come within a couple degrees of the actual direction. Keep in mind you will need to calibrate the app prior to using it but it is very simple to do. In addition, remember that the farther away you are standing from your target, any error in the bearing will be greatly exaggerated so its generally good practice to keep the offset distance to a minimum. For more tips and tricks on GPS data collection visit us at www.cloudpointgeo.com.
Visit us at www.cloudpointgeo.com
has performed many
so far and here are some of the valuable lessons learned from completing this work:
Sign Inventory snapshot from Concord Township in Bureau County, IL
Get the data when you're there
Be thorough when in the field. All too often we come back to the office and wish we had collected more information or question one of the sign attributes. If we take the extra minute or two when out in the field it gives us the best end result and complete inventory. This is one reason that mobile mapping is becoming so popular. You bring much more data back to the office and can post process so much more... eliminating mistakes and questions including saving time and money from repeated site visits.
More data is not always better.
When it comes to feature attributes for GIS work, people can come up with some craze ones... color of sign post, angle of the leaning post, type of hardware.. and the list goes on. Let's be realistic about it. Is this necessary for our inventory and are we really going to maintain all of this information? Focus on what information will be used in the initial inventory and what will be maintained upon future inspections.
One person, start-to-finish.
It's important for one person to be responsible for collecting data and that same person for assembling the inventory. Often times a question comes up that only the person doing the field work will remember. This makes it of critical importance that the same person be responsible for completing the final product.
Begin maintaining your inventory immediately.
Don't let collected data sit on the shelf too long. For one, it helps with the issues described in #3, and it also allows for maintenance of the sign inventory to begin sooner. If you complete an inventory and don't begin maintaining it for several months, by the time you get started it is outdated and you have a lot of work to get caught up.
Be creative with data collection.
It is important to be creative with data collection. You want to work quickly and efficiently when collecting GIS data and this does not always equate to one out-of-the-box solution or software program. At times it may be best to use a mapping software program to collect feature locations and a spreadsheet program to collect data on those features. Other things to consider is how to quickly collect data in the field. Don't rule out ideas such as voice recognition on smart phones or dictation to later be inscribed by other staff back in the office.
There are many things to consider when working on data collection projects, large and small, but most importantly is to remember that proper planning is the key to a successful project.
Those who fail to plan will plan to fail.
Written By: Jonathan J. Hodel, P.E.
Visit us at www.cloudpointgeo.com