Surveying and BYOD: Yes, you can use your smartphone

BRING YOUR OWN DEVICE (BYOD) is not just an industry buzzword. It can change the way professional surveyors work every day. The idea of using a smartphone or tablet instead of a dedicated device is appealing. But is it good enough?

Surveyors and mappers are challenged with the arduous task of data collection that meets accuracy and precision standards and provides adequate attribute information for the project. Before the invention of the electronic data collector, handwritten notes in field books were the norm. Every note keeper’s style varied in content, neatness and thoroughness. Calculations for determining survey data values were completed longhand on paper and were very time consuming.

Index

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• History of Surveyors and Data Collectors
• Trending Away from Proprietary Data Collectors
• How Good Is It?
• Post-Processing (OPUS and DPOS)
• Do You Need a Base Station?
• Adaptation of the Industry
• Receiver, Software Ready for Mobile
• TerraStar Gives Assist to RTK
• Trimble Offers Web-Based Post-Processing
• Atlas Corrections Ready for BYOD

History of Surveyors and Data Collectors

Like its personal computer counterpart, the electronic data collector was introduced in the late 1970s with minimal adoption by the average surveyor because of cost and complexity. Storage methods for the era included magnetic modules and tape; both forms of media were expensive and fragile with little storage for the cost.

Data collection was limited to numeric values only, with horizontal and vertical angles, slope distance, point number and point code being the extent of the information. Couple this process with the limited availability of printers and plotters capable of depicting the data for the surveyor’s use, and one can see why few practitioners invested in these systems.

iOS aerial viewer. (Screenshot: Tim Burch)

The 1980s and 1990s brought significant changes to surveying with the advancing technology of electronic computing and measuring. The introduction of robotic total stations, various methods of GNSS, and even leveling took advantage of significant computer power and measuring processes, and the data collector stayed in lockstep with the advancing instrumentation. Almost every equipment manufacturer developed their own proprietary data collector and software system because of the unique design and programming of their systems.

In the 2000s and later, third-party manufacturers began producing data collectors with advanced computing power and the ability to connect to varying brands of equipment. Most of the programming for these collectors are still proprietary in nature to this day.

Also during the 2000s, a new wave in mobile communications was taking place. Cellular phone and data signals were now being used to transmit an abundance of information between users.

The rapid development of handheld communication devices has led to the meteoric rise of two specific mobile operating systems: one by a radical startup that concentrated on dominating the search engine market, and the other by an avant garde computer company looking to expand its unique customer base.

By the end of the decade, the world had been introduced to the Android operating system by Google, and the iOS operating system by Apple. The combined market share for the two operating systems at press time was just under 98 percent of all mobile devices worldwide.

Trending Away from Proprietary Data Collectors

Android Point Info: Confirmation of collected data, including equipment and base station. (Screenshot: Tim Burch)

Because data collection by surveyors and mappers have traditionally been performed on proprietary systems designed and produced by equipment manufacturers for use with only their instruments, these collectors, while very powerful and robust, are costly for the equipment manufacturers to produce because of the limited market of surveyors and mappers.

Many suppliers, before the introduction of the iPhone and Android operating systems, attempted to adapt their data-collection platforms to wider recognized mobile operating systems (for example, Windows CE/Pocket PC/Mobile) on a bevy of mobile devices (HP/iPAQ, Sony Eriksson, HTC) with little success. Various versions of Windows are still being used today by GNSS equipment manufacturers’ proprietary data collectors, including Trimble, Hemisphere GNSS, Topcon and CHC Navigation.

However, the field of operating environments has become more crowded as technology continues to advance. The proliferation of Windows-based data collectors are now on the decline.

Survey Point: Status of survey data collection and GNSS engine signal reception. (Screenshot: Tim Burch)

Enter Android and iOS. Driving the decline of the previously popular Windows mobile platform is the rapid adoption of the iOS and Android operating systems. These two environments have also led to a substantial number of devices and applications for users.

Part of the reason for the speedy acceptance of the devices and operating systems has been the ease of programming. It is estimated that each operating system has more than two million applications in their respective online stores, with more being introduced daily.

Because of the proliferation of smartphones, nearly everyone is familiar with the look, feel and operation of touchscreen devices and their various applications. This familiarity is driving a new trend in data collection: the concept of “bring your own device” (otherwise known in IT security circles as “BYOD”). BYOD is being introduced by several surveying and mapping equipment manufacturers as an alternative to their proprietary data-collection devices.

Sky Plot: Where the ‘birds’ are in the sky. (Screenshot: Tim Burch)

These manufacturers are pairing iOS and Android developers with their hardware and firmware specialists to create a user-friendly interface that will function on most of the most popular handheld devices on the market today. From Apple iPhones and iPads to Samsung Galaxy phones and tablets, these applications give the surveyor the best of two worlds — sophisticated data-collection capability on a well-known and reliable mobile operating system platform.

The Android platform is becoming especially popular in the handheld mapping market segment. Current users of this environment include Hemisphere GNSS, CHC Navigation, Tersus GNSS and Trimble.

The iOS applications, while not quite as prevalent as Android, are being embraced by several significant GNSS manufacturers, including JAVAD GNSS and Eos Positioning Systems.

These companies are creating iOS and Android apps that embrace the BYOD market, providing their users with affordability and creating a comfort level simply because of the familiarity of the device and its environment.

How Good Is It?

iOS Position. Status of survey data collection and GNSS engine signal reception. (Screenshot: Tim Burch)

For the surveyor to be satisfied with the operation, the collection process must be efficient, cost-effective and easy to use. For this explanation of key items within a well-rounded data-collection application, we are using the JAVAD Mobile Tools (now J-Mobile) application built specifically for the Android and iOS operating systems.

The Android system (Version 7.0) was installed on a rugged CAT S41 cellphone made Bullitt Group from the United Kingdom, while the iOS app was used on the author’s iPad Air 2 running Version 12.2. Both apps were utilized in conjunction with the JAVAD Triumph-2 GNSS receiver.

After putting both versions through trial testing and checking against values on known monuments, here is the results of our findings:

Receiver Setup. Visual reference for leveling and direction of GNSS receiver. (Screenshot: Tim Burch)

Data Organization. Easy to comprehend and flexible for most naming conventions.
Corrections and Sources. Easily connects to base receiver and radio or available NTRIP correction service for real-time network (RTN) capability.

Sky Plot. Because the Triumph-2 is equipped to receive most of the available satellites in service, the Sky Plot feature is beneficial to the user for assessing potential interference.

File Management, Import and Export. Covers the typical file management and transfer functions used by the surveyor.

RTK Survey Operations. Robust telemetry keeps the users informed of specific satellite data and correction status.

Point Confirmation. Survey point information with metadata and equipment listing. (Screenshot: Tim Burch)

Coordinate Systems. All standard coordinate systems are included with features to allow the user to customize their own systems.

Localization. Creation of a local coordinate system is a simple routine, providing strong quality checks for data integrity.

Lift and Tilt. This feature provides the user with a useful procedure to end data collection without the need to press a button. This feature significantly increases the user’s productivity.

Compass and Level Calibration. With the Triumph-2 having an internal compass and level system, status of the receiver is graphically displayed to help the user keep a close watch on the accuracy of the survey point.

Survey Points and Linework. Most point naming systems and line-coding procedures are easily adapted.
Total Station Point Transfer. The creation of control point files for transfer to total stations is simple and easy to use.

Stakeout. Graphical status screens provide the user with simple plotting capability of the desired stakeout point to increase efficiency and accuracy.

These apps are good at providing the surveyor with a solid tool for data collection and staking capability. They are especially good when paired with a real-time kinematic
(RTK) base station or NTRIP correction service.

But what happens when cell service is not readily available, or there are no published monument coordinates to establish site control? These apps have the surveyor covered for that situation as well.

Post-Processing (OPUS and DPOS)

Today’s surveyor works in an environment where geographic-based data is a key component to the services they render to their clients. While most of the world’s developed nations have access to cellular networks in which most GNSS receivers can communicate with an RTN providing corrective solutions, the places where this is not possible relies on other means of data correction.

In the U.S. we rely on OPUS (Online Post-Processing User System) to provide that service. But, as good as it is, it has limitations. Currently, it only utilizes GPS satellite data from the U.S. Department of Defense and is subject to sporadic government shutdowns.

Other services, from both public and private sources, are in place around the world to provide a service similar to OPUS. These include, but are not limited to:

• AUSPOS. Geoscience Australia (free)
• APPS. Jet Propulsion Laboratory at California Institute of Technology (free)
• CSRS-PPP. Natural Resources Canada (free)
• GAPS. University of New Brunswick (free)
• magicGNSS. GMV (free)
• Centerpoint RTX Post Processing. Trimble (free)
• JAVAD Data Processing Service (DPOS). JAVAD (free, processes any JAVAD GNSS jps file)

These correction services utilize other satellite constellations (GLONASS, Galileo, BeiDou and QZSS) for their solutions and can provide additional coverage, depending on the location of the user. Because of these services, geographic-based data is at the fingertips of surveyors worldwide.

JAVAD’s DPOS system is has the ability to collect static survey data and send it to the proprietary service for establishing new coordinate values for base-station use. This process is a function of the app and can be completed in a few short steps.

Once the base station values are calculated, the surveyor can make use of this information for establishing a base station for correction broadcasting.

Do You Need a Base Station?

The establishment of RTNs has greatly enhanced surveying capability as cellular service has increased in coverage and speed. However, there are still instances and locales that do not allow for the reliable use of cell signals to provide those corrections accurately.

Various manufacturers’ tests have proven the accuracy of using an RTN subscription versus the traditional GNSS base and rover RTK setup. But cell-signal strength can be an Achilles heel, crippling those who choose not to set up a base station.

The UHF radio, even in its reduced power state from regulatory changes, is still more powerful and reliable than most cell services. 5G technology and coverage is anticipated to revolutionize cellular service, but it has yet to be realized.

Adaptation of the Industry

Other GNSS manufacturers (including NovAtel, Navcom, ComNav, Unicore, Emcore, Suzhou, TeleOrbit and Geneq) are producing receivers that can be adapted to a variety of existing data collectors and connect to iOS/Android mobile devices through various software developers.

The future of communications remains the smartphone or tablet device, with foldable units expected to be the next big thing.

As processors get more powerful, as chip memory becomes more abundant, and as more satellite constellations orbit in our sky, surveyors and their data collectors will continue to evolve. The future remains bright for technology and the surveyor has a front-row seat.

TIM BURCH is GPS World’s contributing editor for Survey. A professional land surveyor with more than 30 years of experience, he is director of surveying at SPACECO Inc. in the Chicago area. For several years he has been secretary and was recently named vice-president of the Board of Directors of the National Society of Professional Surveyors. He writes a bi-monthly column in the Survey Scene e-newsletter. Subscribe free at www.gpsworld.com/subscribe.

Receiver, Software Ready for Mobile

Photo: ComNav

ComNav receivers offer multiple data-collection device choices via Bluetooth connection, as well as an Android app.

For instance, the G200 provides centimeter-accuracy positioning to any connected mobile devices for RTK field surveying. It is able to delivery robust survey workflows with the SinoGNSS Android-based Survey Master, so that surveyors can collect quality high-accuracy positions no matter what mobile device they are using.

The G200 is a rugged, compact, wearable GNSS receiver. Combined with the high-performance SinoGNSS OEM board tracking GPS L1/L2, BeiDou B1/B2, GLONASS L1/L2, Galileo and QZSS, the G200 enables reliable high-precision GNSS performance for land survey tasks anywhere in the world.

TerraStar Gives Assist to RTK

Photo: Leica Geosystems

NovAtel offers several levels of corrections via its TerraStar service. For surveying applications, the RTK Assist service provides correction data to bridge surveyors through any real-time kinematic (RTK) correction outages. TerraStar services work on NovAtel’s OEM6 and OEM7 receivers..

RTK Assist, available on OEM6/OEM7 receivers, provides 20 minutes of RTK assistance, enabling surveyors to maintain centimeter-level accuracy. A higher service level, RTK Assist Pro, is available on OEM7 receivers. It provides unlimited RTK assistance with stand-alone centimeter-level positioning when RTK is not available.

Trimble Offers Web-Based Post-Processing

Photo: Trimble

Trimble’s CenterPoint RTX Post-Processing Service is a free, web-based solution that provides rigorous processing of GNSS data for users around the globe.

Powered by advanced algorithms for processing static observations, CenterPoint RTX Post-Processing supports data including GPS, GLONASS, Galileo, BeiDou and QZSS. With the service, users can upload GNSS data using Trimble formats or industry-standard RINEX 2 and RINEX 3. The service supports all dual-frequency GNSS receivers and more than 400 different antennas.

The post-processing service computes single-station static observation sessions ranging in length from 10 minutes up to 24 hours, with longer observation sessions recommended to produce the highest accuracy. Using data from the global RTX tracking network, the CenterPoint RTX Post-Processing service computes the position of the observed point with centimeter accuracy.

Results are delivered via email in ITRF coordinates at the current epoch and can be transformed to a fixed epoch by use of a standard tectonic-plate model.

Atlas Corrections Ready for BYOD

The Atlas GNSS global correction service, offered by Hemisphere GNSS, provides correction data for GPS, GLONASS, BeiDou and Galileo constellations. Its global L-band corrections allow for accuracies ranging from sub-meter to sub-decimeter levels. The network has more than 200 reference stations worldwide and covers virtually the entire globe.

Examples of how the AtlasLink webUI looks on a smartphone. (Image: Hemisphere GNSS)

The Atlas platform was conceived to enable as many people as possible to have access to the correction service technology, either as an end-user or as part of their business. Several features are designed to enable customers who use non-Hemisphere positioning systems to have access to Atlas.

For instance, Hemisphere’s SmartLink technology allows an AtlasLink GNSS smart antenna to be used as an Atlas signal extension for any GNSS system compliant with open communication standards.

Hemisphere’s GNSS smart antennas including AtlasLink, A326, C321+ and S321+ offer a user-friendly web user interface (WebUI) that can be used to configure, monitor and manage the receiver from virtually any modern computing device, including computers, phones and tablets.