IceBridge Readies for Arctic Campaign

By George Hale, IceBridge Science Outreach Coordinator, NASA Goddard Space Flight Center

P-3 on the ramp at Wallops
The NASA P-3 airborne laboratory in front of a hangar at Wallops Flight Facility in Virginia. Credit: NASA / Jim Yungel

With IceBridge’s Arctic campaign flights about to begin, scientists, instrument operators and aircraft experts have been hard at work preparing the NASA P-3 airborne laboratory for its long trip north. On Mar. 10, 2014, the P-3, carrying instruments and researchers, flew from NASA’s Wallops Flight Facility in Virginia to Thule Air Base in northern Greenland.

NASA uses a fleet of research aircraft to study things like urban air quality, soil moisture and polar ice, meaning that these aircraft are in high demand. Planes go from one mission to the next with only a few weeks in between to remove the previous mission’s instruments, perform regular maintenance and install equipment for the plane’s next deployment.

Working on servers
Matt Standish of the Center for Remote Sensing of Ice Sheets prepares equipment to go on the NASA P-3. Credit: NASA / Christy Hansen

Removing the instruments gives aircraft technicians the room they need to work on the plane’s engines, electronics and other equipment. Once they are finished, teams install instruments and equipment racks containing the computers and electronics needed to control them.

The moment of truth for this process is a successful test of aircraft and instruments. First, researchers check instruments and wiring on the ground. Once satisfied, the P-3 goes through a series of three check flights: an engineering check flight and two project check flights.

P-3 flight station
Inside the flight station aboard the NASA P-3 during the Mar. 6 project check flight. NASA / Christy Hansen

The first of these three is the engineering check flight, which took placed the morning of Mar. 6. On this flight, P-3 pilots and crew put the aircraft through its paces to make sure things are in proper working order. Later in the day, the P-3 took off again for the first project check flight, and flew along beaches on the Atlantic coast to test the aircraft’s GPS gear and the Airborne Topographic Mapper instrument.

View of Assateague Island, Virginia
View of Wildlife Loop Drive on Assateague Island, Virginia, during the Mar. 6 project check flight. Credit: NASA / Jim Yungel

The next afternoon the IceBridge team took off again for the second project check flight to test the various radar instruments aboard the P-3. To carry this out the team flew south from Wallops and turned out to sea around Virginia Beach, heading for open water. The relatively flat surface of the Atlantic Ocean acts almost as a mirror for the radars, providing a good test environment. Also, by flying far off the coast, the team can test radars without the risk of interfering with electronics on the ground.

After completing these check flights, the team set out to pack their bags and rest before the flight to Greenland. Once leaving Wallops, the P-3 and the IceBridge team will spend the next 11 weeks in the Arctic, collecting valuable sea and land ice data before returning to the United States on May 23.

Grounded in Truth

By George Hale, IceBridge Science Outreach Coordinator, NASA Goddard Space Flight Center
Measuring polar ice from the air calls for the kind of precision flying made possible by GPS, but the usefulness of those satellites doesn’t end there. GPS information like latitude, longitude and altitude make up a crucial part of IceBridge’s instrument data, showing where each data point was collected, and ground-based GPS gives researchers a benchmark useful for checking instrument accuracy. One of IceBridge’s instruments, the Airborne Topographic Mapper (ATM), uses a laser altimeter to build what is essentially a topographic map of the surface. On each flight IceBridge will pass over the airport’s ramp to make sure that the laser altimeter, or LiDAR, is properly calibrated. Because the airport ramps are large, flat and obstruction free areas of known elevation they act as a sort of Rosetta stone, giving the ATM team something to compare their elevation measurements against.

Vehicle with GPS mounted on the roof
Vehicle equipped with a GPS antenna (on roof) before a ground survey of the ramp at Thule Air Base, Greenland. Credit: NASA / Michael Studinger

Having up-to-date elevation data for the entire ramp is the key to these ramp passes. And although IceBridge is an airborne mission this data is collected on the ground by a GPS antenna-equipped car. By driving this car in a grid pattern over the entire ramp and processing the GPS data in specialized software researchers are able to build an elevation map for the entire ramp. This map gives something researchers can use to check instrument readings, and it also reveals something that many people may not expect.

Airport ramps may appear perfectly level and unchanging, but reality is different. First, the elevation of a ramp varies somewhat from one end to the other. “There is a relief of about 3 or 4 meters across the ramp,” said John Sonntag, ATM senior scientist. This relief gives an added benefit though because the slope gives more data to use for calibration. “If the survey shows a tilt of x degrees and the LiDAR shows a tilt of x plus 1, you know you need to make an adjustment,” Sonntag said.

Elevation map of Kangerlussauq airport ramp
Elevation map from a ground survey of the Kangerlussuaq airport ramp. Credit: NASA / ATM team

In addition to sloping, the ramps in Thule and Kangerlussuaq are changing slightly in elevation over time. Obviously any construction or repaving would change elevation slightly, but even the ground itself is rising. Although solid, Greenland’s bedrock has been pushed down and deformed over the years by the weight of the ice sheet. As Greenland’s ice sheet loses mass this downward force lessens and the bedrock starts rising—a process known as isostatic rebound. “In Thule, we’re seeing a rise of about two centimeters per year,” said Sonntag.

Two centimeters may not seem like much, but even that small of a change could affect instrument accuracy. To avoid this IceBridge does ground surveys of the ramps every year or two. Thanks to these regular surveys and continual checking of instrument calibration IceBridge researchers are able to provide the scientific community with accurate measurements of changing polar ice.

Live Twitter chat with Operation IceBridge

NASA P-3 flight deck

Have you ever wondered what it’s like to fly over the Arctic while doing scientific research? On April 8, you can follow NASA’s Operation IceBridge and ask questions about how polar researchers work and the science of polar ice as NASA’s P-3B airborne laboratory flies 1500 feet above Greenland’s ice sheet and glaciers.

IceBridge will post live in-flight highlights on Twitter@NASA_ICE from 10 a.m. to 1 p.m. EDT on Monday, April 8 (weather delay date April 9). Follow along during the flight and hear from the scientists,engineers and guest high school science teachers on board. We’ll also be taking your questions. Just use the hashtag #askNASA.

Sea ice in the Nares Strait west of Greenland

IceBridge Field Work – A Project Manager's Perspective

By Christy Hansen, IceBridge Project Manager, NASA Goddard Space Flight Center

Field work in the Arctic is a unique and challenging experience. It takes an experienced and tough team to complete mission objectives from start to finish despite the biting cold, long days and noisy environment. Early morning temperatures are often in the negative single digits, and the IceBridge team powers through it preparing for flight each day. A typical day’s work can range 12 to 14 hours, a schedule that is repeated daily until the airport is closed or until the flight crew reaches a required hard down day.

My project management perspective allows me to take a step back and appreciate not only the technical expertise of our instrument and flight crew teams, but the masterful choreography that unwinds each day to ensure the P-3B aircraft is prepped and ready, the instruments are powered on and in working condition, and the weather and corresponding science flight plan has been assessed and defined. Being actively involved in all phases of Operation IceBridge makes for a stronger and well-versed leader better able to assist any part of the team at any time. By doing this, I can ensure we are on track to meet our mission and science requirements, assist with troubleshooting in and out of the field, better manage project milestones, and ensure streamlined communication across all IceBridge disciplines with a common goal.

IceBridge project manager Christy Hansen on the stairway to NASA's P-3B.
IceBridge project manager Christy Hansen on the stairway to NASA’s P-3B. Credit: NASA / Christy Hansen
But why do we do this? How do we do this? 

We do all of this in the name of science, collecting polar geophysical data that will help characterize the health of the Arctic and Antarctic. The in-field data and derived data products IceBridge produces are helping to show annual changes in the ice. These data can be entered into models that can more accurately predict what might happen in the future in terms of ice sheet, glacier, and sea ice dynamics, and ultimately sea level rise; all of which have serious consequences for climate change.

But how do we reach these science goals? The steps and teamwork required are simply astounding. Each part of our team is like a puzzle piece and everyone is needed to complete the puzzle. All teams must clearly know their individual responsibilities, but also be able to work together and mesh where their job ends and another begins.

The choreography starts in the beginning, or planning phase where the science team establishes targets of interest on the ice in accordance with our level 1 science requirements. Then our flight planner designs survey flights, having a unique ability to efficiently mesh the science targets with the range and flight dynamic capabilities of the P-3B aircraft.

Next the aircraft office at NASA’s Wallop’s Flight Facility prepares the P-3B for deployment to some of the harshest environments on Earth and supplies the flight crew that executes the specific flight paths over our required science targets. The instrument teams provide the instrumentation—laser altimeters, radars, cameras and a gravimeter and magnetometer—and expertise in operating equipment and processing data during and after flights. Our logistics team deploys to the field ahead of time, establishing security clearances, local transportation and accommodations, and internet and airport utilities.

Finally, our data center ingests and stores the data that our team collects, ensuring it’s useable and available to the wider community. Our data is not only used by polar scientists and other researchers around the world, it is also used to help satellite missions like the European Space Agency’s CryoSat-2 and NASA’s ICESat-2 calibrate and validate satellite instrumentation.

A view of ice from NASA's P-3B airborne laboratory.

A view of ice from NASA’s P-3B airborne laboratory. Credit: NASA / Christy Hansen

And finally, a day in the field …

Assuming a standard 8 a.m. local takeoff and eight hour mission duration, we generally have three major groups who follow different schedules pre-flight each morning.

The P-3 maintenance and flight engineer crew typically starts the earliest, heading to the airport about three hours before takeoff. They prep and warm up the plane, conduct some tests and fuel it, all in preparation for the instrument team arrivals and flight operations.

In parallel with aircraft prep, IceBridge’s project scientist, project manager and flight planner team head to the weather office. The team works with local meteorologists, reviewing satellite imagery and weather models to determine the optimal weather patterns that support our flight requirements—clear below 1500 feet, the altitude we typically fly—and final target selection.

In the meantime, the instrument teams arrive at the aircraft to power up and check their systems prior to takeoff. By 7:30 a.m., the aircraft doors close, and we take off by 8. Our eight-hour flights range between flying high and fast, to low and slow over our targets, which include geophysical scans of ice sheets, glaciers, and sea ice.

We typically land around 4 p.m., close out the plane, check data and meet at 5:30 for a science meeting. Many folks continue to work for a few hours afterward, processing data or writing mission reports. All of this is repeated daily, for up to 6 days in a row, which can be exhausting, but in the name of important scientific research, an amazing team, and majestic polar landscapes, I could not imagine anything else.


Crew members working on the P-3B. Credit: NASA / Christy Hansen

Teacher and Science Adviser to Experience IceBridge

By Jette Rygaard Poulsen, Math and Physics Teacher, Hasseris Gymnasium, Aalborg, Denmark

Danish science teacher Jette Rygaard Poulsen

Danish science teacher Jette Rygaard Poulsen

Jette Rygaard Poulsen is the science adviser for the Danish Ministry of Education, and in this role she is participating in developing new subjects for the Danish high schools. One of the latest examples is the combination of physics and geography where a special focus on the Arctic areas could be extremely relevant. Poulsen is working on how Operation IceBridge can contribute. Not only with raw data from measurements, but also with general information on the flying laboratory and the equipment usage. This insight can be coupled directly to the mathematical models the Danish students are already using during their education. Poulsen is also the coordinator of Danish teachers participation in Operation IceBridge.

Apart from her advisory work for the Ministry, Poulsen is also teaching physics and math at the general high school Hasseris Gymnasium in Aalborg, Denmark. Poulsen graduated from Copenhagen University as M.Sc in Meteorology, and has since maintained a special interest in the Arctic climate.

Greenland Teacher to Gain Insight on Arctic Ice

By Mette Noort Hansen, Science Teacher, GU Sisimiut, Sisimiut, Greenland


Sisimiut, Greenland, science teacher Mette Noort Hansen

I teach introductory science, arctic technology, geography and biology to high school students in Sisimiut, Greenland, where I moved to from Denmark in July 2012. I have a M.Sc. in biology and geography and am interested in nature and the environment, both professionally as a teacher and personally in the form of hiking, skiing, botanizing or other activities.

I heard about the possibility of joining the IceBridge mission through a science newsletter for high school teachers in Greenland, and from my colleague Sine, who joined the mission in 2012. I hope that the mission will give me and future students an insight in contemporary research regarding the melting of polar ice, and a better understanding of what the research tells us, compared to what the media tells us.

Following IceBridge I will develop a theme for introductory science, regarding glaciers, the research done in IceBridge, and the definition of science. The product is made available for all science teachers in Greenland in June 2013, as part of a larger web-based teaching-platform for Greenlandic high school teachers.

PolarTREC Teacher's Path to IceBridge

By Mark Buesing, Libertyville High School, Libertyville, Ill.


Libertyville High School physics teacher Mark Buesing

Libertyville High School physics teacher Mark Buesing

I teach physics and AP physics at Libertyville High School in Libertyville, IL – about 45 miles northwest of Chicago. My undergrad is in electrical engineering from the University of Illinois and I worked for a number of years at Hughes Aircraft in California and Motorola in Illinois. After a short stint as a professional bicycle racer, I found out I was meant to be a high school physics teacher, and earned a graduate degree in secondary education from Roosevelt University. I’ve been teaching now for almost 20 years.

My route to Operation IceBridge was serendipitous. A former student of mine works for the US Antarctic Program, and while in Antarctica, she met a science teacher participating in the PolarTREC program (Teachers and Researchers Exploring and Collaborating). This student sent me an e-mail telling me about the program and encouraged me to apply. That application was selected by Operation IceBridge, which has a very active educational outreach program.

My students asked me what I’ll be doing in Greenland with NASA, and I told them, “You are the next generation of scientists and engineers. Who are the next people NASA will hire to help continue all the research? … You!” So my job is to bring the science Operation IceBridge does back to my class and help motivate students to pursue careers in science and engineering. In the not-too-distant future, if the kids in my class today are working on a project like Operation IceBridge I will have done my job.

IceBridge personnel and Buesing in Fairbanks, Alaska.
From left: Michael Studinger, IceBridge project scientist; Mark Buesing, Libertyville High School physics teacher; and Christy Hansen, IceBridge project manager

NASA Operation IceBridge: Notes from the Field (Arctic 2013)

By Sinead Farrell, Sea Ice Scientist, NASA Goddard Space Flight Center / University of Maryland

Editor’s note: This entry was originally posted on the Scientist’s Soapbox, a blog published by the Earth Science System Interdisciplinary Center at the University of Maryland in College Park, Md. 

Introduction:

The NASA Operation IceBridge mission began the Arctic 2013 research campaign on Monday 20th March. The mission will survey the Greenland Ice Sheet and sea ice pack of the Arctic Ocean. The NASA IceBridge mission is now in its fifth year and continues to measure Arctic sea ice thickness and snow depth. These data continue the time series of ice thickness measurements begun with NASA’s ICESat in 2003, and will provide a link to the NASA ICESat-2 mission, due for launch in mid-2016.

Surveys are conducted using a specially-equipped P-3B research aircraft (see photo below) that flies above the ice carrying a number of science instruments including radar and laser altimeters, and high-resolution cameras. This year the first flight took place from Thule, Greenland over Arctic sea ice north of the Lincoln Sea, on Wednesday 20th March. IceBridge flew beneath the European Space Agency’s CryoSat-2 satellite, that carries a special radar altimeter known as SIRAL. The mission was designed to fly a gridded-survey beneath the satellite to help validate CryoSat’s measurements over sea ice. The aircraft then transited from Thule across the Arctic Ocean to Alaska on Thursday 21st March. Over the coming days IceBridge will attempt a number of sea ice flights over the Beaufort and Chukchi Seas from a base at Fairbanks International Airport, Alaska. ESSIC’s Sinead Farrell hopes to participate in the first Alaska mission on Friday 22nd March, pending good weather. Dr. Farrell is a sea ice scientist and member of the NASA IceBridge science team.

View of a sea ice lead from the NASA P-3B.
View of a sea ice lead from the NASA P-3B. Credit: NASA / Christy Hansen

Daily Blog Posts:

Tuesday 19th March: Arrived in Fairbanks, Alaska on Tuesday to slightly warmer spring temperatures than I had expected. After organizing a rental car, figuring out how to use the engine heating block and the all-wheel drive, I headed for the hotel to unpack and (re)familiarize myself with the locale. The last time I enjoyed an extended visit to Fairbanks was exactly ten years ago, while I was conducting my graduate studies at University College London. Back then I also participated in a NASA airborne campaign over the Chukchi, Beaufort and Bering Seas aimed at validating the NASA AMSR-E radiometer. Things have not changed much in Fairbanks over the years!

Wednesday 20th March: The first in a series of IceBridge science flights was successfully completed on Wednesday. Although the mission was conducted far away over Arctic sea ice northwest of Greenland it was nonetheless a very exciting mission to follow. I was involved in designing a set of gridded flight-lines over the ice such that our airborne survey would provide temporally and spatially coincident measurements with CryoSat-2, while it passed high over-head. This is a technically challenging flight to conduct but things worked out well. The sea ice appeared more dynamic than we had expected, but the number of cracks in the ice, known as “leads”, will actually help in the data analysis aimed at inferring sea ice thickness. While waiting for the IceBridge mission to transit from Greenland to Alaska, I will spend time visiting the International Arctic Research Center (IARC), at the University of Alaska – Fairbanks (UAF). On Wednesday I had the opportunity to meet with some of my colleagues at IARC to discuss on-going and future projects to better understand the diminishing Arctic sea ice pack. I was also able to attend a lecture by Dr. Ron Kwok of NASA’s Jet Propulsion Laboratory on the topic of “Recent Changes in the Arctic Sea Ice Cover: A remote sensing perspective”. Fortuitously there are many national and international sea ice scientists visiting UAF right now to participate in meetings and workshops. Some are even en route to conduct field-work on the sea ice near Barrow, Alaska. Although it’s very cold (-19 degrees Celsius this morning!) and snowing, this is a great time of the year to be in Fairbanks!

Thursday 21st March: Thursday began with the exciting news that the NASA P-3 was en route to Fairbanks. Today’s mission from Greenland to Alaska was flown along what is called the “Laxon Line”. The flight is named in honor of University College London Professor Seymour Laxon. Seymour, my graduate advisor, died tragically 3 months ago. Seymour was a pioneer in the use of satellite altimeters to study sea ice and was the lead sea ice scientist on the CryoSat-2 mission. Today we measured ice thickness and snow depth along a flight line that crosses most of the Arctic Ocean. Thanks to a good tail-wind the P-3 landed one hour early in Fairbanks, right around lunch time. I was really lucky to watch the plane land with my colleagues Jackie Richter-Menge from the Cold Regions Research and Engineering Laboratory (CRREL) and Pam Posey from the Naval Research Laboratory (NRL). Once through customs we met our colleagues off the plane and welcomed them to snowy Alaska!

Friday 22nd March: On Friday we hope to conduct a third sea ice mission over the Arctic, weather permitting. We always need good weather to fly our surveys since clouds can potentially interrupt the measurements we make from the aircraft. We’re particularly interested to see what is happening to the sea ice in the Southern Beaufort Sea this year after the ice pack suffered a wide-spread “break out” event in mid-February. This event caused the ice pack to fragment into smaller floes and become more dynamic. Although these break-out events are not unusual in this region, they do not normally happen in February, the dead of winter. We will provide more updates as the day progresses.

The NASA P-3B on the ramp at Fairbanks, Alaska.
The NASA P-3B on the ramp at Fairbanks, Alaska. Credit: NASA / Jim Yungel

IceBridge Arctic 2013 Check Flights Complete

By George Hale, IceBridge Science Outreach Coordinator, NASA Goddard Space Flight Center

On Mar. 14 and 15, the IceBridge team carried out project check flights in preparation for the Arctic campaign. After an engineering check flight earlier in the week to make sure everything is properly secured inside the aircraft, scientists and a small number of instrument operators board the P-3 to begin flights over the Wallops Flight Facility airfield and beaches near Wallops Island, Va., to test the Airborne Topographic Mapper (ATM) and Digital Mapping System (DMS) and over the Atlantic Ocean to test the Multichannel Coherent Radar Depth Sounder (MCoRDS), the snow and accumulation radars, and Ku-band radar altimeter.

These check flights have two main purposes. The first is to test the equipment to make sure it’s all in working order and the second is to collect data that is used to calibrate the instruments. Every time an instrument is installed in a research aircraft it’s important to make sure that nothing has changed since the last time it was flown.

Flight paths for both IceBridge check flights.

Flight paths for IceBridge check flights on Mar. 14 (blue) and Mar. 15 (red). Credit: NASA

Ground tests can catch many alignment and installation problems, but the real moment of truth comes in flight tests. On the afternoon of Mar. 14, the IceBridge team took off for flights near Wallops to test the ATM and DMS systems and check other electronics. By flying a level flight at varying altitudes, the teams can collect data that ensures their instruments are properly calibrated.

Different materials reflect light to varying degrees, which can make a difference with a laser-based instrument like ATM. Because IceBridge is measuring snow and ice, highly reflective materials, the ATM team will often test over sandy areas the beaches near Wallops. This is because sand reflects light in a similar way to ice. Another test is to check areas near each other with widely different albedos, for example, the white numbers and surrounding dark pavement on the runway. If light and dark targets next to each other show the same elevation then the instrument is calibrated properly.

The NASA P-3B at Wallops Flight Facility before the IceBridge check flight on Mar. 14, 2013. Credit: NASA / Kyle Krabill
The NASA P-3B at Wallops Flight Facility before the IceBridge check flight on Mar. 14, 2013. Credit: NASA / Kyle Krabill

Similarly, the team tests the DMS instruments to make sure the camera is aligned properly and that focus and frame rate are set appropriately. The rate at which the DMS camera captures photos depends on the aircraft’s speed and altitude, with lower altitude and higher speeds needing a faster rate to ensure proper coverage.

On Mar. 15, the team took off in the morning to do final checks of the P-3B’s radar instruments. Instead of flying along the beaches near Wallops, the P-3 headed out 200 nautical miles over open water in the Atlantic Ocean. The reason for doing this test over the ocean is twofold. First, U.S. law prevents IceBridge from operating its radars inside the country, and second, the ocean surface acts almost like a mirror for the radar, making it ideal for testing. By comparing transmit and return signal strengths at different altitudes, the team can make sure the radar is working properly.

The P-3B returns to Wallops after the first of two IceBridge check flights. Credit: NASA / Kyle Krabill
The P-3B returns to Wallops after the first of two IceBridge check flights. Credit: NASA / Kyle Krabill

Signal strength, however, is only part of the picture. MCoRDS is made up of several antennas in an array, with each antenna’s signal recorded separately. To make sure that each element is aligned correctly, the P-3B climbs to a high altitude and banks left and right while researchers measure how the return signals change during the maneuver. These maneuvers are also the reason why the radars are tested on a separate day from ATM and DMS. Once the plane banks more than 15 degrees, its wing blocks these instruments from seeing GPS satellites in orbit and both ATM and DMS need accurate GPS data to work properly.

With the check flights complete it is nearly time for IceBridge scientists, instrument team members and flight crew to make the trip to Thule, Greenland, to start the 2013 Arctic campaign. The P-3B is scheduled to make the transit flight from Wallops early on the morning of Mar. 18, and the first science flight is scheduled for Mar. 20.

Preparations for Arctic Campaign Under Way

By George Hale, IceBridge Science Outreach Coordinator, NASA Goddard Space Flight Center

An IceBridge field campaign is the culmination of months of planning and preparation. At January’s science team meeting, scientists focused the campaign’s goals and provided mission planners the details needed to finalize flight plans. With these final details ironed out the next step was to start preparing the tools of the trade, IceBridge’s aircraft and instruments. For the past several days, instrument teams and aircraft technicians at NASA’s Wallops Flight Facility in Wallops Island, Va., have been getting the P-3B ready for the 2013 Arctic campaign, which is scheduled to have its first science flight on Mar. 20.

Operation IceBridge is but one of several missions to use NASA’s P-3B airborne laboratory. After each mission, this aircraft returns to its home base at Wallops where it undergoes repairs and routine scheduled maintenance needed to keep it flying at peak efficiency and where science instruments are swapped out. This rotation of airborne science missions keeps the Wallops aircraft team busy, preparing between three and five missions per year. “Sometimes it’s more and sometimes it’s less,” said P-3B flight engineer Brian Yates. “We’re working on some relatively large projects, so we have five this year.”

NASA's P-3B airborne laboratory in a hangar at Wallops Flight Facility as it is being prepared for the upcoming Arctic campaign.

NASA’s P-3B airborne laboratory in a hangar at Wallops Flight Facility as it is being prepared for the upcoming Arctic campaign. Credit: NASA / George Hale

After the aircraft’s maintenance is complete and the previous mission’s equipment has been removed, the IceBridge team starts installing the mission’s suite of science instruments. This process can be generally divided into a few portions: installing the instrument and the equipment needed to control it and collect data, testing the individual instruments and checking to make sure the aircraft and instrument suite work together as they should.

The first step is installing the components that gather the data, such as cameras, radar arrays and laser transceivers. The Airborne Topographic Mapper (ATM) laser and Digital Mapping System (DMS) cameras are installed in bays on the underside of the aircraft. Each of these instruments looks down through windows in the plane’s belly. The Multichannel Coherent Radar Depth Sounder (MCoRDS) antenna is attached to the underside of the aircraft. Previously this has included antennas under the wings, but IceBridge is flying with a trimmed down MCoRDS instrument with an array beneath the P-3B’s fuselage.Additional radar instruments like the accumulation and snow radars and Ku-band radar altimeter are also installed at this time.

The MCoRDS radar antenna on a cart prior to being attached to the underside of the P-3B.

The MCoRDS radar antenna on a cart prior to being attached to the underside of the P-3B. Credit: NASA / George Hale

While this hardware was being installed on the plane, other members of the instrument team put together all of the hardware needed to operate the instruments in metal racks that are then securely bolted to the floor of the plane. Making sure everything is securely fastened is crucial because of the often turbulent nature of low-altitude polar survey flights.

ATM equipment racks waiting to be installed in the P-3B.
ATM equipment racks waiting to be installed in the P-3B. Credit: NASA / George Hale

Once everything is in place and secured the next step is to make sure the instruments work properly. This means rounds of testing both on the ground and in the air. Ground testing involves checking instrument connections and alignment. “We’ll check on the camera to make sure it’s seeing through the window ok and not catching the edge,” said DMS field engineer Dennis Gearhart.

Everything being used in this IceBridge campaign has flown before, but it’s important to make sure the instruments are working properly.”We want to make sure things work as well as they did when they were put into storage,” said ATM program manager James Yungel. To do this, the ATM team will bounce the laser off a ground target 500 feet away.

The MCoRDS antenna secured to the underside of the P-3B.

The MCoRDS antenna secured to the underside of the P-3B. Credit: NASA / George Hale

The real test of all this work comes with the mission’s check flights on Mar. 13 and 14. The first flight, known as an engineering check flight is carried out with flight crew only and is to ensure that everything is properly installed and secured. Scientists and instrument operators participate in the second flight, where instruments are powered on and tested. “The check flights are a final arbiter,” said Yungel.

This year’s IceBridge Arctic campaign will run from Mar. 18 through May 3. The P-3B will operate out of airfields in Thule and Kangerlussuaq, Greenland, and Fairbanks, Alaska.