Category: Survey

  • Septentrio Completes Acquisition of Altus Positioning

    Septentrio Satellite Navigation has completed the acquisition and integration of Altus Positioning Systems. Septentrio said the acquisition strengthens the company’s focus on highly accurate and reliable GPS/GNSS positioning equipment, and the integrated company will continue to focus on developing emerging markets across the globe and increase advancements in the field of GIS.

    “At the heart of this fusion are our customers,” said  Antoon de Proft, CEO and president of Septentrio, “They will benefit from this unique opportunity, which combines the knowledge and experience of Septentrio in GNSS positioning with experience of Altus-PS in survey, mapping and GIS; and from an expanded offering of products and services under one group.”

    Septentrio Satellite Navigation and Altus-PS started working together in 2007. The collaboration between the two companies resulted in a series of successful products such as the APS-NR2, APS-3, APS-U and APS-GeoPod, surveying and GIS products that provide essential accurate and reliable results and ease of operation, Septentrio said in a statement. The smart antenna products will form a product line in the Septentrio product portfolio.

    The acquisition brings key capabilities and synergies in other areas such as testing, manufacturing and delivery, which will now be based from Septentrio’s corporate headquarters outside the Belgian city of Leuven.

    Neil Vancans
    Neil Vancans

    Neil Vancans, formerly president of Altus-PS, now becomes vice president of Septentrio Americas. “The fusion of our two companies is a logical step in our evolving business relationship and professional collaboration,” Vancans said. “We look forward to leveraging the strengths of both our organizations to grow the market for Septentrio products across a wide range of market sectors and build the same level of success for Septentrio products in the American market that we have enjoyed elsewhere in the world.”

    Septentrio designs, manufactures and sells high-precision multi-frequency, multi-constellation GPS/GNSS equipment used in demanding applications in a variety of industries such as marine, construction, agriculture, survey and mapping, GIS and UAVs. Septentrio receivers are available as OEM boards, housed receivers and smart antennas.

  • Hemisphere GNSS Debuts Atlas GNSS Correction Service

    Hemisphere GNSS Debuts Atlas GNSS Correction Service

    Atlas_Graphics-1-W

    Hemisphere has released Atlas, its new entrant into the GNSS global correction services market. Atlas is delivered via L-Band or the Internet at accuracy levels ranging from meter level to sub-decimeter level. Atlas support is being introduced across a wide range of hardware, including Hemisphere’s new AtlasLink smart antenna, also launched.

    “Atlas comes out of a change of culture and focus,” Hemisphere CEO Chuck Joseph told GPS World in an extensive interview that also included Rodrigo Leandro, Hemisphere’s director of engineering, GNSS Positioning Systems. For the full interview, see the second half of this news story.

    Starting June 19, Atlas will be available for subscription at the dedicated Atlas web portal across a range of Hemisphere’s multi-frequency, RTK-capable products, such as AtlasLink, R330u, V320 and VS330u. Atlas will also be available from a number of Hemisphere’s channel partners and OEMs such as Carlson Software, Inc.

    “Since joining Hemisphere I have heard from customers large and small that they need a different option when it comes to high-accuracy corrections, one they can buy from their provider of choice and with little to no impact on their operating budgets,” said Chuck Joseph, Hemisphere GNSS CEO and president. “We listened hard to what they told us and built Atlas to answer their needs — a totally new service that delivers freedom of choice to our customers along with industry leading corrections at dramatically reduced prices.”

    “We formed a team of our most experienced GNSS professionals with the task of developing a roadmap for the future of correction services business and technology in the world — assessing current needs, and also what users across the globe will be looking for over the next decade or two,” said Rodrigo Leandro, Hemisphere director of engineering. “Atlas not only introduces Hemisphere as a business and technology leader in the correction services industry today, it also provides an essential platform for delivering multiple levels of correction services to a very wide range of users spanning commercial business and consumer application use.”

    Systems supporting Atlas utilize the newly released and proven Athena GNSS engine. To be able to utilize Atlas corrections, users of supported systems will simply need to update to Athena firmware and purchase a subscription through the Atlas portal.

    To build Atlas, Hemisphere GNSS put together a team of seasoned developers whose collective experience matches the best in the GNSS industry. Together they have developed a GNSS correction service, available via L-Band satellite broadcast, which utilizes the most powerful technologies available to deliver a service that matches or exceeds competitive systems across a range of metrics:

    • Positioning accuracy: Atlas provides competitive positioning accuracies down to 2 cm RMS in certain applications.
    • Positioning sustainability: Position quality maintenance in the absence of correction signals, using Hemisphere’s Tracer technology.
    • Scalable service levels: Atlas is designed to serve all. It is capable of providing virtually any accuracy, precision and repeatability level in the 5 to 100 cm range.
    • Convergence time: Convergence times of 10-40 minutes.
    • Exclusive agnostic capability: Atlas is an agnostic positioning system. SmartLink technology allows an AtlasLink antenna to be used as an Atlas signal extension for any GNSS system compliant with open communication standards.
    • Network RTK augmentation: BaseLink technology allows Atlas-capable receivers to self calibrate, self-survey, and automatically manage the transmission of RTK correction data to augment or extend established or new GNSS reference networks in areas of poor Internet connectivity.

    Hemisphere-Atlas-table
    “High-quality corrections are essential to our customers,” said Randy Noland, director of Machine Control, Carlson Software, Inc. “The way all the existing services are purchased, delivered and supported is completely separated from the rest of the positioning ecosystem. We see Atlas as an opportunity for us to deliver corrections under our own brand as part of a holistic package — all of which means empowering our ability to provide a stronger solution and a better experience for our customers.”

    “Atlas completely changes how augmentation services are delivered and supported,” said Andy Smith at Saderet Ltd. “For the first time, distributors and dealers can fully participate in selling to and supporting our customers, strengthening our relationships by providing them with a much better experience.”

    “I’ve extensively tested Atlas, and the performance is exceptional, making it a great fit for our GIS and survey customers” said Jean-Yves Lauture at Eos Positioning Systems, Inc. “Even better, we can now offer global augmentation services with our Arrow GNSS receivers to our customers as part of an integrated solution. After many years in this industry, that’s a major change.”

    Atlas service levels and position accuracies can be customized to meet OEM needs, the company said.

    Exclusive Interview with Hemisphere’s Chuck Joseph and Rodrigo Leandro

    A Startup Inside a Reinvention

    “Atlas comes out of a change of culture and focus,” Hemisphere CEO Chuck Joseph told GPS World, in an extensive interview that also included Rodrigo Leandro, Hemisphere’s director of engineering, GNSS Positioning Systems. “We are reinventing a storied brand, and to do that we have to act more like the startups I have directed since leaving Trimble — move fast, be flexible, and focus on innovation. Effectively we are building a startup inside of a reinvention.”

    “On my first day on the job, we divided the staff into five working groups and told them: you are now startup companies, entrepreneurs, with six people each team. Go away and come back with big ideas. Go build a business plan. Out of that we got Athena, released last month, Atlas, AtlasLink, and a couple more new products coming out in the months to come.”

    A Different Kind of Corrections Service

    Joseph and his colleagues at Hemisphere describe the distribution, pricing, and overall business model of Atlas as “disruptive.”

    “Our approach comes directly from talking to customers in agriculture, machine control, and to our channel partners. Other corrections service providers did not allow them to participate, forced them to give up their end user list, and to buy directly from [the service provider] — who in some cases was their competitor in that market.”

    “When you step back you can see the impact of those restrictions — after 10 plus years the corrections service marketplace generates probably $150 million in total revenue — it should be bigger than that by now. We think a different approach combined with a very aggressive price point will substantially broaden the marketplace.”

    “We’ll be making announcements of OEM signings in the months to come. For us it’s all about what works for our partners — some of them will private-label the service, some will choose to use the Atlas brand. We really don’t care if our name is on the product or not — we’re an OEM play. Whatever brand they choose, we will provide them with the infrastructure to be successful, even down to the portal their customers will use to manage their devices and subscriptions — we will develop that for them, and provide the back-end e-commerce.”

    A Look at the Technology

    Rodrigo Leandro added, “The basic architecture is not extremely different from other L-band reference services. However, within that, we have really pushed to develop leading-edge technology. For example, our correction method format is well-developed for new constellations and different applications it can serve, and our corrections message structure is the most advanced of those available today. As a result, we have a number of patents pending on technologies included in Atlas.”

    Chuck Joseph interjected, “When we were doing the initial planning for Atlas we agreed that it was absolutely critical that our performance meets or beats the competition’s, otherwise we wouldn’t want to offer it to customers out there. We have been benchmarking the competition at every stage of our development, and know that we are delivering a market leading product.”

    “This slide shows the same, single antenna connected to Atlas and to a competitor, and it shows being able to converge down to decimeter level.

    Chart: Hemisphere GNSS

    “This one gives more details on time to converge.

    Chart: Hemisphere GNSS

    “And here, this one shows pass-to-pass results, the relative accuracy between 2 tracks of the tractor — this is important for people more interested in agriculture applications. We can get down to 2.5 centimeters.”

    Chart: Hemisphere GNSS

    “The new AtlasLink antenna is designed to be a main channel for customers of our service. It can be used in GIS, machine control, marine applications and so on. Features inside it include a very big internal memory storage, a web server application, multi-GNSS multi-frequency capability, L-band and RTK — it supports Atlas and Athena out of the box. Other innovations will come later, for instance, incorporating Galileo. We believe it is the most powerful multi-purpose GNSS smart antenna in the industry.”

    “At the same time there is easy support and easy configuration by the user. It takes literally about six clicks from log-in to register the receiver, out of the box. In 20 minutes you’re running Atlas. It’s very easy to get up and running.”

    Broadening the Market

    Leandro continued, “The Atlas service isn’t the only area of innovation however. We also spent a lot of time working on how we could deliver the service to the broadest possible audience, and the resulted in two key features of our AtlasLink antenna — SmartLink and BaseLink. Those features free customers from the restrictions of their current hardware and current service — they really change the game.”

    “Customers don’t want to have to buy a new $10-$20K receiver [in order to get a corrections service]]. If you’re happy with the hardware you’re currently running, there’s no need to change it, you can still get this service. We are not in the business of using the service to sell hardware. We are using the hardware to sell the service.”

    Joseph concluded, “This is all good for OEM customers. For them the SmartLink and BaseLink capabilities are huge. They can go back into their installed base and not have to push people to upgrade receivers or get a brand new receiver. At the same time, it enables them to go after their competitors installed base, and opens up markets that previously weren’t available such as recreational marine service, for example, the lower end of the marketplace. Fundamentally, we want to change this market — enable more users to get access to correction, and deliver real choice to those that have it already.”

     

  • Trimble Expands UAS Portfolio with Mutlirotor Partnership

    Trimble Expands UAS Portfolio with Mutlirotor Partnership

    Trimble displayed the Multirotor G4 Surveying Robot at the AUVSI Unmanned Systems Show in May.
    Trimble displayed the Multirotor G4 Surveying Robot at the AUVSI Unmanned Systems Show in May.

    Trimble is partnering with unmanned aircraft system (UAS) manufacturer Multirotor service-drone, GmbH. The collaboration will allow Trimble to expand its existing UAS portfolio to provide its customers with additional solutions to choose from based on their aerial imaging project needs.

    Multirotor service-drone, based in Germany, is a manufacturer of multirotor systems. Trimble will be Multirotor service-drone’s exclusive provider of multirotor vehicles for aerial mapping use in surveying, construction, mining, agriculture, oil and gas, and utilities. The combination of Multirotor service-drone’s stable and reliable platforms with Trimble’s industry-leading sensor technology and workflow efficiencies will provide customers with best-in-class solutions for aerial data capture.

    Unmanned multirotor systems are powerful solutions for visually documenting smaller areas, vertical structures or environments where holding position is important. High-resolution imagery, orthophotos, terrain models and normalized difference vegetation index (NDVI) map deliverables created from multirotor data provide valuable information for the survey, engineering and agriculture industries that Trimble serves, the company said.

    “We are very excited to partner with Multirotor service-drone. At Trimble we’re always looking for ways to meet our customer’s needs and enable them to solve the complex problems they encounter every day,” said Todd Steiner, product marketing director in Trimble’s Geospatial Division. “The collaboration will enable our customers to use a technology rapidly growing in popularity due to its flexibility and productivity.”

    Founded in March 2011, Multirotor service-drone quickly became a market leader in the area of professional unmanned aerial systems. In 2013, service-drone acquired competitor Multirotor and together developed the award-winning fourth-generation flight control system used in its service-drone products today. Multirotor service-drone offers a broad range of commercially used UAS within the 8 to 50 pound (4 to 25 KG) weight class. Designed and manufactured in Germany, Multirotor service-drone products are built to deliver safety, quality and consistency for professional applications, according to the company.

  • Cold Assets: GeoDecisions Platform Used to Track Icebergs

    Cold Assets: GeoDecisions Platform Used to Track Icebergs

    This photo shows drifting icebergs from the Amundsen during research expedition. (Photo: courtesy of Greg McCullough, University of Manitoba)
    This photo shows drifting icebergs from the Amundsen during research expedition. (Photo: courtesy of Greg McCullough, University of Manitoba)

    A Canadian expedition team used GeoDecisionsGeoILS platform to help track icebergs during a voyage to better understand how icebergs drift. An intelligent location server using the Esri ArcGIS platform, GeoILS enables users to monitor and locate assets and facilitate quick and coordinated responses.

    GeoDecisions, an information technology company specializing in geospatial solutions, partnered with Solara Remote Data Delivery Incorporated, Canada’s Carleton University and Esri during the project.

    Led by University of Manitoba Scientist David Barber, the crew of Canadian Coast Guard Icebreaker Amundsen sailed off the coast of Newfoundland and Labrador to research ice hazard mitigation, the effects of climate change, and polar region technology requirements. GeoILS location intelligence helped crew members visualize, analyze, and leverage project-pertinent data.

    “During the expedition, researchers and scientists used GeoILS to assess drifting through sensor monitors attached to the icebergs,” said Brian Smith, vice president of commercial solutions with GeoDecisions. “In addition to reporting and notifications, GeoILS provided the project team with maps that were tailored by selecting desired iceberg information and the geographic area of interest based on user-defined criteria.”

    Above is a representative snapshot of GeoILS’ features and range of functionality used during the Canadian iceberg expedition.
    Above is a representative snapshot of GeoILS’ features
    and range of functionality used during the
    Canadian iceberg expedition.

    GeoDecisions’ data portal was used with Iridium Solara tracking devices during the iceberg research project. “We are excited to provide tools to scientists who are gaining critical insights into the behavior of icebergs and global climate change,” said Tom Tessier, president of Solara Remote Data Delivery Incorporated.

    Solara Field Tracker 2000.
    Solara Field Tracker 2000.

    “GeoILS and the satellite tracking beacons worked very well during this project,” added Derek Mueller, assistant professor and physical geography program supervisor with Carleton University. “Thanks to our partners’ efforts, we now have a great new suite of tools for examining our data.”

  • FOIF GNSS Receivers Aid with Australian Pipeline Survey

    Photo: FOIF GNSS Receivers

    Three years ago, engineering survey company G & C Sadlier Design was engaged to perform a route selection and centerline pegging survey for a gas pipeline duplication between Somerton in Victoria and Young in New South Wales, Australia. To accomplish the work, G & C Sadlier Design turned to FOIF GNSS receivers.

    So far, about 225 kilometers have been surveyed and constructed, with 306 kilometers still to be surveyed, designed and built, according to surveyor Greg Sadlier. The current focus is a 100-kilometer section in Victoria and a 70-kilometer section in New South Wales. Recently completed are two linear static control surveys over 80 kilometers in Northern Victoria and 70 kilometers at the end of the project near Young in New South Wales.

    Photo: FOIF GNSS Receivers

    “These surveys have been done using a FOIF F60 Base GNSS receiver and two FOIF A30 Rover receivers. (Two one-man survey crews are used),” Sadlier said. The procedure is to set up the F60 base over a point with known coordinates and elevation, approximately in the center of the alignment to be surveyed.

    The base was set first, to record 1-second data to the datacard over the duration of the survey. One surveyor started the base, and surveyed forward to the end of the alignment, and the other rover crew started at the beginning of the alignment and surveyed towards the base. The rovers were also set to record 1 second data to the datacard.

    “The control points were 0.75-m steel star pickets driven flush with the ground surface, and witnessed with a galvanized 1.5-m steel star picket,” Sadlier explained. “Each rover point was surveyed for 20 minutes plus 1 minute per kilometer of the distance to the base. That is, a point that is 35 Km from the base will be occupied for 55 minutes or 3300 epochs. With the control points at easy accessed positions, usually roads crossing the alignment, at intervals of about 8 kilometres mean that the survey of 80 Km is completed in one day.

    Photo: FOIF GNSS Receivers “We have found the FOIF GNSS receivers are very easy to use, and the epoch readout on screen is very reassuring that the data is being stored, and easily confirms that the correct amount has been stored. The data is easily downloaded from the card and converted to Rinex format with FOIF RnxTransform. The data was post processed by a third party.”

    The control survey results were adjusted (Helmert adjustment) onto check Permanent Marks at both ends. “This made a rotation of 0°00’00.001” and a shift of 0.007 meters E and 0.005 meter N. An elevation difference of .035 meters was manually adjusted out over the 80 kilometers,” Sadlier said.

    “We are now using the control survey while surveying the route selection and features survey,” Sadlier said. “We have two RTK base locations at the 25-kilometer mark and 52-kilometer marks, and using our VHF radio solution have coverage over the entire job with a 10-kilometer overlap in the center.

    “We have found that RTK observed control readings of 180 epochs return residuals of less than 010 meters for both coordinate and elevation for all the static control points. Very impressive results considering the length of the survey,” Sadlier said.

    The engineering firm has yet to process the New South Wales data, but expects the same or better, Sadlier said, as the overall length is a little less and the surveyed control points were in more open country with less tree cover.

     

     

     

     

  • Kenya Land Survey Efforts Aided with Spectra Precision Equipment

    Kenya Land Survey Efforts Aided with Spectra Precision Equipment

    Photo: Kenya Department of Surveys The Kenya Department of Surveys has acquired eight Spectra Precision Focus 30 total stations and an additional eight Epoch 50 GNSS receivers as part of an ongoing major effort to adjudicate land and prepare deeds, according to Spectra Precision.

    Until recently, 67 percent of Kenya had yet to be adjudicated even as the work was supposed to be completed within 20 years after it was commissioned in 1957 by the British colonial government, according to the Lands Cabinet Ministry of Kenya. To rectify the problem, the government of President Uhuru Kenyatta two years ago began a major new push to produce three million titles by 2017. So far, the Land Surveys Department reports that 800,000 title deeds had been prepared and are being distributed.

    Oakar Services Ltd., an East Africa geospatial firm, provided the consulting services that led to the Department of Land Survey’s purchase of the Spectra Precision total stations and GNSS receivers.

  • Surveyors Invited to ‘Survey Earth in a Day’ — in 4D

    Survey-Earth-in-DayOn the day of the solstice, June 21, geospatial professionals around the world and members of Land Surveyors United (a global support network for land surveyors) will be simultaneously recording survey-grade GPS data from thousands of points around the globe, to gain a more accurate understanding of the earth’s surface.

    Measurements made on Survey Earth in a Day 4D (SEIAD) will serve as comparative data from prior events and to expand upon the database of logged points. “This year it will be called 4D, as we will be layering the data from our previous three years into a single map, representing points data gathered from thousands of locations around the planet by professional surveyors,” organizers said. “This day is the largest geospatial event in history as it allows surveyors to participate in their own location. With close to 3,000 more members than we had last year, we are hoping that all of you will participate from your location on June 21.”

    In 2012 the first Survey Earth event was held, establishing many new understandings between geospatial and geomatics professionals and the general public on geospatial issues, organizers said. “With a mission not only to learn more about the Earth’s surface but also monitor its changes over time, and the changes in public perspective, as a global community, we may be more capable of assessing our future,” organizers said.

    Also, International Surveyors Week 2015 occurs during the week, which ends with SEIAD. Visit the event website to sign up and learn how to participate, or follow SEIAD on Facebook.

  • INTERGEO Conference in Stuttgart Focuses on Future

    InterGeo-logo

    The conference program and registration for INTERGEO 2015 are now live. Register before July 31 to benefit from the early-bird booking rate.

    The conference will open with keynote speeches by Chris Cappelli (Esri Inc.) on “The Age of the Location Platform: How Mapping and GIS are Transforming the Work Environment” and Prof. Georg Gartner (TU Wien, Vienna University of Applied Sciences), president of the International Cartographic Association, on “The Future of the Map – the Map of the Future.” 

    “The agenda for the INTERGEO conference in Stuttgart is packed with exciting topics that are the focus of ongoing political debate on the digital world and will play a key role in shaping the way we work in future,” reads a statement by INTERGEO. “With keynote speeches and plenary talks delivered in English and simultaneous interpreting provided for one strand of the conference on the second day, it is clear that INTERGEO is also becoming increasingly significant on an international scale.” 

    The major topic of discussion at 2014’s INTERGEO remains a key part of the conference this year — INSPIRE examines geo-issues from a European perspective, providing practical examples and focusing on further development of the European directive. Other central themes include geodata as a basis for construction management and land development, a major concern for future development at regional and local level, as well as issues relating to property markets and valuation. These subjects are all crucial when it comes to discussing the “smart cities” and “smart villages” of the future, according to INTERGEO.

    Another highlight of INTERGEO in Stuttgart this year will be the panel discussion on the second day on “Geospatial Information – A Key Element for Emerging Markets.” The high-profile panel of speakers include Bengt Kjellson (UN-GGIM Europe), Ola Rollen (Hexagon), Steve Berglund (Trimble) and Chris Cappelli (Esri Inc.).

    A further key topic at the conference that is set to have a profound effect on the working world is geoinformation and mobility. DDGI and DVW will be addressing this together and discussing practical examples in two event strands.

    The contributions on big data will focus on the rapid development of data capture, processing and presentation as well as the direct integration of data into business processes. Geoinformation as an element of networked processes is a subject of major international significance, as evidenced by the conference’s high-profile speakers. “In terms of digitization, the conference will be key to paving the path to Geospatial 4.0 and the networking of digital geodata,” said Prof. Karl-Friedrich Thöne, president of the event’s host, DVW, adding, “INTERGEO is the ideal forum for creating processes that could eventually benefit the entire value-added chain.”

    As important as data may be in the digital world, it is also crucial to have the right visualization concepts in place. This will be demonstrated through presentations on the German Cartographers’ Day, which will form part of INTERGEO this year.

  • JAVAD GNSS Remote Assistance and Monitoring Services

    JAVAD GNSS Remote Assistance and Monitoring Services

    Together with free live technical support provided by practicing professional land surveyors via phone, email, message board and text messaging, JAVAD GNSS is pleased to announce the release of another innovative product, RAMS, Remote Assistance and Monitoring Services for J-Field software. J-Field is the field controller software developed for the TRIUMPH-LS GNSS receiver and the VICTOR-LS field controller. RAMS is currently available to all users of J-Field, JAVAD’s powerhouse software for survey data collection, stakeout, and computations.

    Photo: JAVAD GNSSWith the J-Field enabled receiver/controller connected to the Internet (via internal GSM SIM card, Wi-Fi hotspot or Ethernet), users can make their receiver/controller accessible to JAVAD’s customer support team from anywhere in the world with three button presses. “It’s like having the support person looking over the user’s shoulder,” said Shawn Billings, a surveyor from Texas.

    While the TRIUMPH-LS is connected to RAMS, the user and support person share control of the receiver, giving the support person the ability to make changes to settings on the receiver or train the user remotely. “It has changed the way support is conducted, making us more efficient at determining issues and more effective in training users,” said Billings. The connection is password-protected to ensure that only those intended have remote access to the receiver.

    Beyond technical support, RAMS server access is available to the user community as well. This offers the ability for project managers to remotely supervise crew efforts in the field. Because operational control of the TRIUMPH-LS/VICTOR-LS is shared between the server user and the field user, the server user (project manager) could perform the more complex operations of land surveying, such as COGO calculations and localizations, as necessary, and then allow the field user (crew member) to continue the more routine tasks of data collection.

    Photo: JAVAD GNSSShould the task be simpler to accomplish with office software, RAMS allows file transfer directly from the LS to the server user’s own computer and vice versa, thus enabling the project manager to easily export points, linework (dwg, dxf, shape), vectors, photos and other project-related data from the LS to his desktop. From there, he can manipulate the data in his desktop application and then copy files, with newly computed coordinates or linework, back to the LS for the crew to work with in the field. In this way, RAMS uniquely supports the obligation surveyors have to exert responsible charge over their field crews.

    The full receiver control, the access to receiver files, the robust RTK features of the TRIUMPH-LS and the fully customizable collection settings in J-Field make site monitoring possible as well.

    RAMS server can be accessed with almost any device with an Internet browser and Internet access. “I’ve used RAMS server to assist customers from my desktop computer, laptop, android tablet and even my cell phone,” Billings added. “Using JAVAD’s RAMS server requires no installation of software on the remote device, only an Internet connection and web browser.”

    For those wanting to operate RAMS on their own server, the RAMS Server application is available from JAVAD GNSS. An Android version of RAMS Server is also available, allowing users to connect an Android device directly to the TRIUMPH-LS without the need for an Internet connection. RAMS for Android creates a local network between the Android device and the LS and allows a field user to see and manipulate J-Field with the Android device should it be necessary to work with the LS beyond the reach or view of the user.

    For more information on RAMS, J-Field, TRIUMPH-LS, VICTOR-LS and other JAVAD GNSS solutions, visit www.javad.com, email [email protected] or call 408-770-1770.

     

  • Establishing Orthometric Heights Using GNSS — Part 1

    Establishing Orthometric Heights Using GNSS — Part 1

    Editor’s Note: This month, we introduce a column by David B. Zilkoski, one of our two new Survey Scene editors. Zilkoski has worked in the fields of geodesy and surveying for more than 40 years, including serving as director of the National Geodetic Survey. See his full bio at the end of this article. He is joined by coeditor David Doyle, who contributed the May column.


    The Three Types of Heights Involved in Computing GNSS-Derived Orthometric Heights

    By David B. Zilkoski

    David B. Zilkoski
    David B. Zilkoski

    This column is the first in a series of newsletters discussing issues associated with establishing orthometric heights using GNSS. The purpose of my columns is not to promote a particular procedure or process, but to provide the reader with information and analysis tools to consider when using GNSS to estimate orthometric heights.

    This information is not new. During the past two decades, I have written several articles and papers on estimating GNSS-derived orthometric heights and presented numerous seminars describing guidelines on how to estimate GNSS-derived heights. However, due to the automation of technology and “blackbox” processes, many users are accepting results without performing the proper analysis to ensure that their results are reasonable and correct. These processes and procedures are not difficult to perform, but they can be very beneficial to obtaining an understanding of the accuracy of your results and ensuring your results are correct.

    To understand how to estimate GNSS-derived orthometric heights at centimeter-level accuracy, you must have a basic understanding of the types of heights involved, how these heights are defined and related and how accurately these heights can be determined. In other words, you need to obtain a basic understanding of ellipsoid, geoid and orthometric heights and how they are related and their estimated accuracies.

    To adequately address these topics, a series of Survey Scene newsletters will be separated into several sections. Some of this material will be a review (and probably boring) for those of you that have been performing GNSS-derived orthometric height surveys but, hopefully, you will gain a little benefit from the review. For those of you just starting out, I hope this will whet your appetite to obtain a better understanding of heights.

    The following is a brief outline of what the columns will address:

    • Description of the three types of heights involved in computing GNSS-derived orthometric heights. That is, the definition of ellipsoid, geoid and orthometric heights, and how they are related. The user should understand what potential issues can arise due to how each height was defined, modeled and published. For example, in the United States, what errors exist in the published NAVD88 heights due to the leveling network design and remaining systematic errors in the leveling data? Constraining a North American Vertical Datum of 1988 (NAVD 88) published height that’s less accurate than your GNSS-derived orthometric height may allow your results to be consistent with the surrounding published heights, but could be distorting the rest of your results. In the end, you may need to do that, but you should know how your decision has influenced the rest of your results. I was the NAVD 88 project manager, so I know where all the problems are hidden. I am just kidding about knowing where all the problems are hidden, but there are issues associated with performing a nationwide network adjustment. NGS’ latest scientific geoid models can be useful in identifying potential issues in NAVD88.
    • Basic procedures for detecting published NAD 83 (2011) ellipsoid height outliers and how repeatability does not mean accuracy. Why you can’t assume that the published ellipsoid heights between two closely spaced stations is accurate to the published formal errors.
    • A description of the differences between a scientific gravimetric geoid model and a hybrid geoid model, and why it is important to use both geoid models in your analysis. The latest NGS hybrid geoid model, Geoid12B, is made consistent with the published NAVD 88 heights. This means you will be consistent with NAVD 88 when using GEOID12B to estimate GNSS-derived orthometric heights. However, this doesn’t guarantee that your GNSS-derived orthometric heights are accurate. NGS’s new beta experimental geoid height model xGEOID14B is not distorted to fit the published NAVD 88 heights, so it is useful for identifying valid NAVD 88 benchmarks.
    • Basic procedures for validating NAVD 88 height constraints used to estimate GNSS-derived orthometric heights. How to ensure your monuments haven’t moved since their last survey, and how good are your leveling-derived orthometric height constraints? Based on all available information and data, basic procedures to determine how good the final set of GNSS-derived orthometric heights really are. NGS 59 guidelines outline basic rules and procedures that need to be adhered to for computing accurate NAVD 88 GNSS-derived orthometric heights.
    • A description of NGS’ proposed 2022 Vertical Reference Frame and why it will be a good replacement for NAVD 88.

    Background

    Since 1983, NOAA’s National Geodetic Survey (NGS) has performed control survey projects in the United States using GPS satellites. NGS used these early GPS surveys projects to develop guidelines and procedures to estimate GPS-derived orthometric heights. These publications are known as NGS 58 and NGS 59.

    Over the past three decades, GNSS surveying techniques have proven to be so efficient and accurate that they are now routinely used in place of classical line-of-sight surveying methods for establishing vertical control networks at the 2-cm level. Understandably, interest has been growing in using GNSS techniques to replace all leveling requirements. During the next decade, scientists will continue to develop better models and tools to facilitate GNSS-derived orthometric heights replacing classical line-of-sight surveying for many applications. In the meantime, it is important to have a clear understanding of the basic concepts of establishing GNSS-derived orthometric heights, otherwise water (or something worse) may not flow “down hill.”

    Let’s start with a review of the three types of heights used when estimating GNSS-derived orthometric heights and how they are related.

    Types of Heights and Their Relationship

    Orthometric heights (H) are referenced to an equipotential reference surface, e.g., the geoid. The orthometric height of a point on the Earth’s surface is the distance from the geoidal reference surface to the point, measured along the plumb line normal to the geoid. These are the heights most surveyors have worked with in the past and are often called mean sea-level heights.

    Ellipsoid heights (h) are referenced to a reference ellipsoid. The ellipsoid height of a point is the distance from the reference ellipsoid to the point, measured along the line that is normal to the ellipsoid. Years ago, the term ellipsoid height may have been a new concept to many traditional surveyors, but prevalent today because ellipsoid heights are readily derived from GNSS measurements.

    At the same point on the surface of the Earth, the difference between an ellipsoid height and an orthometric height is defined as the geoid height (N). It should be noted that h=H+N is an approximate equation because H is measured along the plumb line normal to the geoid, where h is measured along a line normal to the ellipsoid (see Figure 1). For all practical survey projects, this small difference can be ignored.

    Figure 1. Relationship of ellipsoid, geoid and orthometric heights.(Figure from POB article by David Zilkoski, The GPS Observer column, Feb. 28, 2001)
    Figure 1. Relationship of ellipsoid, geoid and orthometric heights.(Figure from POB article by David Zilkoski, The GPS Observer column, Feb. 28, 2001)

    Several error sources that affect the accuracy of orthometric, ellipsoid and geoid height values are generally common to nearby points. Because these error sources are in common, the uncertainty of height differences between nearby points is significantly smaller than the uncertainty of the absolute heights of each point. This is the key to establishing accurate orthometric heights using GNSS.

    Orthometric height differences (dH) can then be obtained from ellipsoid height differences (dh) by subtracting the geoid height differences (dN):

    dH = dh – dN

    Each of these heights and height differences have systematic errors that are accounted for by following appropriate procedures during data acquisition, by applying corrections based on environmental conditions and models, and/or estimating parameters using adjustment techniques. There will always be remaining errors that are not accounted for, and you must perform the appropriate procedures to detect, reduce or eliminate these errors in the final set of GNSS-derived orthometric heights.

    Relative Accuracy Estimates

    Adhering to NGS guidelines (NGS 58), ellipsoid height differences (dh) over short baselines (less than 10 km) can now be determined with 2 sigma uncertainties that are typically better than +/ 2 cm. The requirement that each baseline must be repeated and agree to within 2 cm of each other, and they must be repeated on two separate days, during different times of the day, should provide a final GNSS-derived ellipsoid height better than 2 cm at the 2-sigma level. The requirement that spacing between local network stations cannot exceed 10 km helps to keep the relative error in geoid height small.

    Adding in the small error for the uncertainty of the geoid height difference and controlling the remaining systematic differences between the three height systems will produce a GNSS-derived orthometric height with 2-sigma uncertainties that are typically +/- 2 cm. Therefore, it is possible to establish GNSS-derived orthometric heights to meet certain standards, not millimeter standards, but 2-cm (95%) standards are routinely met now using GNSS.

    When high-accuracy field procedures are used, orthometric height differences can be computed from measurements of precise geodetic leveling with an uncertainty of less than 1 cm over a 50 kilometer distance. Less accurate results are achieved when third-order leveling methods are employed. Depending on the accuracy requirements, GNSS surveys and present high-resolution geoid models can be employed as an alternative to classical leveling methods.

    In the past, the primary limiting factor was the accuracy of estimating geoid height differences. With the computation of the more accurate National high-resolution geoid models, e.g., GEOID12A, the limiting factor is ensuring that the NAVD 88 orthometric height values used to control the project are valid. Strategically occupying benchmarks with GNSS that have valid NAVD 88 height values is critical to detecting, reducing or eliminating blunders and systematic errors between the three height systems. (Note: Valid NAVD 88 height values include, but are not limited to, the following: benchmarks that have not moved since their heights were last determined, were not misidentified, and are consistent with NAVD 88.)

    Conclusion

    This newsletter addressed the basic concepts of GPS-derived heights. To reiterate, it is important that you understand there are three types of heights involved with estimating GNSS-derived heights: ellipsoid, geoid and orthometric. Each of these heights has its own error sources that need to be detected, reduced or eliminated by following specific procedures or applying special models. This series of newsletter columns will address these potential errors sources and provide procedures to assist you in identifying these errors.

    My next column in this series, coming in the August Survey Scene, will review guidelines for detecting, reducing or eliminating error sources in ellipsoid heights, and provide a brief discussion on using published NAD 83 (2011) ellipsoid heights in your analysis.

    References

    NOAA Technical Memorandum NOS NGS-58, Guidelines for Establishing GPS-derived Ellipsoidal Heights (Standards: 2 cm and 5 cm), Version 4.3.

    NOAA Technical Memorandum NOS NGS-59, Guidelines for Establishing GPS-derived Orthometric Heights (Standards: 2 cm and 5 cm), are available. These guidelines address the establishment and densification of vertical control networks through the use of GPS surveys and valid NAVD 88 orthometric control.


    David B. Zilkoski has worked in the fields of geodesy and surveying for more than 40 years. He was employed by National Geodetic Survey (NGS) from 1974 to 2009. He served as NGS director from October 2005 to January 2009. During his career with NGS, he conducted applied GPS research to evaluate and develop guidelines for using new technology to generate geospatial products. Based on instrument testing, he developed and verified new specifications and procedures to estimate classically derived, as well as GPS-derived, orthometric heights. 

    Now retired from government service, as a consultant he provides technical guidance on GNSS surveys; computes crustal movement rates using GPS and leveling data; and leads training sessions on guidelines for estimating GPS-derived heights, procedures for performing leveling network adjustments, the use of ArcGIS for analyses of adjustment data and results, and the proper procedures to follow when estimating crustal movement rates using geodetic leveling data.  

  • $100 for 300 Well-Chosen Surveyor Words

    If you are a professional land surveyor, we’d like to hear from you! Send us a brief account of how you use GNSS in your surveying work, what tips and tricks you can share with other surveyors, and what other hardware and software you are combining with GNSS to get the job done.

    Submit around 300 words, although you can certainly go longer if you wish. Five winners will be chosen from the submissions received at [email protected]; winners will be chosen on the basis of clarity, liveliness, and, in some small measure, the unusual nature of the surveying tasks you perform or the way you go about them. Winners will receive $100 gift cards.

    But we’re interested in hearing about straight run-of-the-mill jobs, too! Send your entries to [email protected]. Some entries may also be chosen for further development into articles for this newsletter, or GPS World magazine, or other publishing opportunities.

  • TerraGo Edge 3.6 Features Enhanced Support for High-Accuracy GPS

    TerraGo Edge 3.6 Features Enhanced Support for High-Accuracy GPS

    Photo: TerraGoTerraGo Edge 3.6 is now available. TerraGo Edge 3.6 features enhanced support for high-accuracy GPS receivers on both iOS and Android, as well as a host of new mapping features, basemap sources and integration with Google Earth.

    “TerraGo Edge’s enhanced support for EOS and SXBlue receivers helps users take advantage of real-time, high-precision GPS receivers while getting all the productivity benefits that come with the smartphone and tablet user experience,” said Brian Mickel, technical consultant, LHNav. “This is the future of GPS data collection where mobile users can integrate independent GPS receivers to get whatever level of accuracy the job requires.”

    New features in version 3.6 include:

    • Sub-meter and cm precision with SXBlue and EOS GPS receivers for iOS and Android
    • Polygon and polyline note support added on iPhone and Android
    • Auto-drawing polygons and polylines from GPS points
    • Multi-note view on iPhone and Android
    • KML import and export added to growing list of data interfaces, improves Google Earth integration
    • New mapping features and editing of polygon notes
    • New “over-zoom” feature allows extreme map zooming on all devices and basemaps
    • Brand new basemap source options

    TerraGo Edge is an open GPS data collection solution, helping customers replace outdated handhelds and proprietary databases with an open, modern, mobile solution that meets the needs of all stakeholders. For the field users, TerraGo Edge delivers any level of precision with unparalleled support for a full range of Bluetooth GPS receivers on Android and iOS.

    For the manager, TerraGo Edge provides a real-time dashboard for monitoring field users and data collection. For GIS users, TerraGo Edge provides accuracy settings that ensure GPS data quality, with tools for QA and open export to any GIS or CAD system.

    A free trial of the TerraGo Edge app for iOS or Android is available.