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MARCH 2017

ANTARCTIC OASIS Thought Leader Product Review Economics Part 2 Death of the PLSS? JAVAD GNSS J-Tip Payroll and Revenue An Oasis in » ERIK DAHLBERG

Displayed with permission • The American Surveyor • March 2017 • Copyright 2017 Cheves Media • www.Amerisurv.com Adapting GNSS methods to scientific needs

t first glance, the research station located in James Ross phrase “Antarctic Island’s unique post-glacial environment. oasis” seems to be The scientific program at Mendel is an oxymoron. But an ongoing effort supervised by the MU that’s how polar Faculty of Science. The Czech Republic Aresearchers refer to the north end of has been involved in polar research for James . The largest island roughly three decades. Scientists from in the James Ross archipelago at the MU have conducted studies in the extreme northern tip of the Antarctic Antarctic since 1994, including multina- Peninsula, James Ross Island is shielded tional research programs and expeditions. from storms by the Trinity Mountains. A major part of the research at While glaciers cover 80 percent of its Mendel focuses on glaciology and land area, the island has large regions permafrost. The work also includes that are free of year-round ice. Until earth sciences of geology, geomorphol- it collapsed in 1995, a large ice shelf ogy, geochemistry, climatology and connected the island to the peninsula hydrology; biological disciplines such mainland. The exposed rock and tundra as botany, ecology, microbiology and provide important opportunities for soil biology; and paleontology. Yes, research and scientific activities. dinosaurs. Scientists have uncovered One of the newest scientific facilities dinosaur fossils in two separate geologi- is the Johan Gregor Mendel Research cal formations on James Ross Island. Station located on the Ulu Peninsula at In late 2015, a team of 11 MU scientists the far north end of the island. Named conducted the 10th expedition to the after the Czech scientist known as the station. They would continue the work of father of modern genetics, it is the Czech observation and data collection and follow Republic’s first permanent Antarctic up on the activities of earlier visitors. research facility. The station formally opened in 2007 after several years of Positioning at the planning and construction. Commonly Antarctic Circle referred to as the Mendel Polar Station, Like many scientific efforts, position the facility is owned by Masaryk information is an essential part of David Jindra collects GNSS data near the University (MU) in Brno. The station, routine data collection. Researchers Mendel Polar Station. Scientists use GNSS to which is built on permafrost, is the only need to map the location of specimens support a variety of research projects at the Czech facility in Antarctica.

Displayed with permission • The American Surveyor • March 2017 • Copyright 2017 Cheves Media • www.Amerisurv.com A group of penguins “supervise” David Jindra and a group of Jindra as he collects GNSS observations. curious penguins on a beach at James Ross Island.

and samples to correlate the data and to For research in this enable them to return to the exact same “ location for future work. And investigations region, accuracy of to characterize the behavior of the island’s glacier surfaces require the ability to make a few centimeters is accurate position measurements over time. However, the time and resources generally sufficient. available for accurate positioning are ” limited. Working under tight budgets, the researchers at the Mendel Polar Station generally sufficient,” Jindra said. “The effort must share duties that extend beyond their and time to achieve millimeter precision scientific roles. Necessary tasks such as could not be justified. The scientists have cooking, cleaning and maintenance occupy other things to worry about.” a significant portion of the time. Therefore, The need for small, simple equipment the processes to capture positions must be led the Czech researchers to select Trimble® simple, efficient and combine readily with GeoExplorer® series GNSS handhelds for the scientific activities. the project. In addition to convenient size According to David Jindra, a GNSS and and low power consumption, the onboard positioning expert and Trimble Geospatial Trimble Terrasync software was well-suited processing for geospatial data including distribution partner who accompanied the for the attribute-intensive data collection GNSS, total stations, digital levels as well 2016 expedition, the sparse geodetic control work. The handhelds could provide the as image management and processing for and lack of any real-time GNSS network durability and easy workflows needed terrestrial and aerial photogrammetry. near the station further hampered the for the work and Jindra’s methodology The software also produces a variety of positioning efforts. As he spent time with would increase productivity and accuracy. deliverables for use in GIS, CAD and other the researchers and began to understand For data processing, the team would use downstream systems. Pathfinder Office is their workflows and requirements for Trimble Business Center (TBC) and Trimble focused on GNSS post processing primarily accuracy, Jindra developed a strategy that GPS Pathfinder® Office software. Developed for mapping and GIS applications. would streamline the work. “For research in to support surveying and engineering One of the first tasks was to establish this region, accuracy of a few centimeters is applications, TBC provides analysis and suitable control at the Mendel Polar Station.

Displayed with permission • The American Surveyor • March 2017 • Copyright 2017 Cheves Media • www.Amerisurv.com A GNSS handheld on a tripod serves as a reference station for positioning at the Mendel Station. A mark on the boulder provides a stable reference point.

The nearest precise control point was at the the Chilean station to point 4003. Jindra positioning into their daily activities. With Chilean General Bernardo O´Higgins station compared the long-duration observations the Geo7X collecting data at the reference on the more than 50 with measurements taken during past cam- station, scientists carried Trimble GeoXH™ km (30 mi) away. Using a Trimble Geo7X paigns and confirmed that 4003 was indeed 6000 series GNSS handhelds to more GNSS handheld mounted on a tripod, Jindra stable. The dual-frequency, carrier-phase remote locations, ranging up to 15 km (9 mi) created a new reference point named “4003.” results reinforced the plans to use 4003 as from the base. All of their GNSS data could After collecting dual-frequency data over a reference station for the 2016 campaign. It be processed against the data from 4003. several days, Jindra downloaded the data will also provide a reference point for use by Because the baselines were in 15-km range, from the Geo7X and acquired corresponding future expeditions. they produced better accuracy than earlier data from the Chilean station. He then used When the local control was in place, expeditions that tied points to the distant TBC software to compute the baseline from the researchers could incorporate GNSS O´Higgins station. In addition to the shorter

Displayed with permission • The American Surveyor • March 2017 • Copyright 2017 Cheves Media • www.Amerisurv.com year (6.5 to 10 ft), position accuracy of a few centimeters is sufficient. Following a process that is repeated every year, the team measured several hundred points on the glaciers to quantify changes in position at the bamboo rods. Data from the recurring measurement of coordinates is combined with remote sensing and climatology data to develop information about the glaciers’ evolution, motion, trends and shrinking volume. While more complex data analyses are conducted after the Tight quarters at Mendel Station combined sleeping areas and expeditions return home, they rely heavily workspaces. Team members on accurate GNSS data. Jindra said because shared common tasks of cooking, the teams could work quickly and confirm cleaning and station maintenance. each day’s data, the researchers came away with a high level of confidence in their results. They could also use TBC and lines, the ability to collect dual-frequency produce accurate positions at the bamboo Pathfinder Office to produce output and data reduced the time needed for GNSS rods with just three minutes of occupation reports formatted for use by other software observation at each location. time. Each day’s data was processed and analysis tools. in Pathfinder Office to produce 3D Because permafrost represents a Science in the Antarctic coordinates. “As you would expect, working continuously fluctuating material, another One of the most important uses of GNSS at on the glaciers was a good environment goal of the research was to better understand the Mendel Polar Station is for monitoring for GNSS,” Jindra said. “There are no the behavior and evolution of the ground at glaciers. Scientists are studying four glaciers obstructions and the satellite availability the station. For their studies on permafrost, on the island within 15 km of the station. was always quite good.” Because the glacial the team used GNSS approaches similar to On three glaciers, networks of bamboo rods motion could be on the order of 2-3 m per the glacier measurements. They identified are installed into the ice at regular intervals. Researchers use GNSS to measure the 3D position at the base of each rod. They also measured the distance from the top of the bamboo to the ice surface. To streamline the GNSS portion of the work, Jindra trained the scientists to use the stop-and-go kinematic method (SGK). The SGK approach is used to obtain precision similar to RTK but without the need to have a base station or other source of real-time corrections. The GNSS receiver collects satellite data continuously while in motion between points of interest. It is held stationary at a point for a few minutes. The in-motion and stationary data is down- loaded to post-processing software, which can then produce centimeter results. Jindra selected the SGK technique because the continuous tracking of satellites could produce precise positions with short occupation times. With the handhelds collecting data continuously, they could Scientists use a laser to check verticality while drilling for core samples in the permafrost. The cores are used in studies including microbiology and climatology in the post-glacial region.

Displayed with permission • The American Surveyor • March 2017 • Copyright 2017 Cheves Media • www.Amerisurv.com Researchers return to the Mendel Polar Station on James Ross Island. The station is in one of the island’s “oases” where permafrost is exposed during summer months.

several experimental and containers to areas for soil detect any motion sample collection related to shifts in on nearby mesas. the permafrost. By The locations of the establishing the local collection points control point 4003, Researchers install a were marked and Jindra provided meteorological sensor accurately measured on James Ross Island. a fixed reference using the stop-and-go The stability of the for monitoring the kinematic technique. locations can be checked structures using very They also recovered over multiple seasons. short GNSS baselines. a number of points Work at Mendel previously established alternated between by British teams on volcanic hummocks and The Busy Season science and survival. Because of the small established precise coordinates on the sta- The Mendel Polar Station operates only dur- (11-person) team, everyone had multiple tion’s climate and meteorological sensors. In ing the Antarctic summer. The small facility duties. In addition to managing the nearly all cases, the GNSS system produced consists of a station building and several GNSS measurements, Jindra helped with coordinates with accuracy well within the shipping containers repurposed for use as cooking and station operations. He assisted team’s needs. The points were cataloged and storage and other purposes. Solar panels the science efforts by collecting water monitored; the GNSS data will enable future and small wind turbines supply electricity. samples, reading and recording various expeditions to continue precise observation As part of the scientific efforts, the teams climate sensors, and catching penguins for of the points in coming years. conducted measurements on the buildings biological studies.

Displayed with permission • The American Surveyor • March 2017 • Copyright 2017 Cheves Media • www.Amerisurv.com A GNSS handheld collects data on the corner of a building at the research station. Repurposed shipping containers provided storage and supported the station’s self-sufficient energy system.

Jindra conducted some research of his Using Trimble ViewPoint RTX correction RTX technology for scientific activities in own as well. He wanted to examine the services, he tested the system at Mendel Antarctica remains open. performance real-time GNSS positioning Polar Station and at an Argentinian station After two short, intensely busy weeks, using satellite-delivered GNSS correction on roughly 75 km (47 mi) part of the expedition departed Mendel Polar services in the Antarctic. He said that the southwest of Mendel. While it was possible Station. The data they collected will support Trimble RTX™ high-accuracy GNSS cor- to receive the ViewPoint RTX corrections months and years of processing and analysis. rection technology utilizes an established in Antarctica, Jindra was concerned about Plans are already underway for future visits global reference station network along accuracy in the remote location. by Czech teams to James Ross Island. While with satellite orbit and clock data to supply When used with the R1 receiver, the Jindra won’t be accompanying the next corrections for high accuracy positions in ViewPoint RTX service is capable of produc- expeditions, he is pleased that he was able to real time. The corrections can be supplied ing sub-meter accuracy; Jindra was able to contribute to the scientific efforts. at different levels of accuracy and via confirm that performance. In both locations “The new methodology will bring cellular Internet connection or satellite he obtained sub-meter real-time positions more accurate and valuable results to all broadcast. Trimble RTX includes different with less than one minute of convergence applications in future campaigns,” Jindra levels of accuracy to suit specific needs. time. “Our tests have documented that explained. “This combination of different One example is the Trimble ViewPoint Trimble RTX corrections are functional at geospatial technologies and methods is the RTX service, which can provide accuracy the area of northern Antarctic Peninsula,” right way to reach a maximum quality and that is equal to or better than differential Jindra said. “In the future, they could be complexity of scientific activities results in GPS (DGPS). Because ViewPoint RTX used for a spectrum of precise collection of this unique area.” ◾ corrections can be delivered by satellite, the geographical data. It’s important not only for solution can operate in remote areas where the scientific community. Other applications Erik Dahlberg is a writer specializing in the DGPS reference stations are not available. can benefit by knowing that real-time sub- geomatics, civil engineering and construction industries. Drawing on extensive training and To conduct the tests, Jindra used a meter to meter accuracy can be achieved experience, Dahlberg focuses on applications Trimble Juno® 3B handheld connected via in Antarctic locations and conditions.” He and innovations in equipment, software and Bluetooth® to a Trimble R1 GNSS receiver. said that the question of broader usage of techniques.

Displayed with permission • The American Surveyor • March 2017 • Copyright 2017 Cheves Media • www.Amerisurv.com