CryoSat passes first operational tests

From the European Space Agency, it looks like CryoSat-2 is working well. I’m sure we are all looking forward to seeing what the results are.

CryoSat-2's radar altimeter is able to measure the freeboard of sea ice, that is the height of ice protruding above the water. From the freeboard, the ice thickness can be derived. Credits: ESA – AOES Medialab

ESA’s ice mission delivers first data

13 April 2010

ESA’s CryoSat-2 has delivered its first data just hours after ground controllers switched on the satellite’s sophisticated radar instrument for the first time. CryoSat-2 was launched on 8 April and has been performing exceptionally well during these critical first few days in orbit.

Europe’s first mission dedicated to studying variations in our planet’s ice cover entered polar orbit just minutes after launch last Thursday, marking the start of three days of intense activity. Mission controllers at ESOC, ESA’s European Space Operations Centre, have been monitoring CryoSat-2 around the clock to ensure the satellite’s systems and payload were functioning normally.

The CryoSat-2 satellite was launched at 15:57 CEST (13:57 UTC), 8 April, on a Dnepr rocket provided by the International Space Company Kosmotras, from the Baikonur Cosmodrome in Kazakhstan. The signal confirming that it had separated from the launcher came 17 minutes later from the Malindi ground station in Kenya.

Cryostat2  successfull launch
CryoSat-2 launch

By Sunday morning, 11 April, ESA’s Flight Director Pier Paolo Emanuelli declared that the formal Launch and Early Orbit Phase (LEOP) was complete and said, “The satellite is in excellent condition and the mission operations team quickly resolved the few problems that came up. It’s been a very smooth entry into orbit, precisely as planned.”

Later on Sunday, CryoSat-2’s primary instrument, the Synthetic Aperture Interferometric Radar Altimeter (SIRAL), was switched on for the first time and started gathering the first radar echo data.

SIRAL’s first data were acquired at 16:40 CEST and were downloaded and processed at ESA’s Kiruna ground station.

“We switched SIRAL on and it worked beautifully from the very start. Our first data were taken over the Antarctic’s Ross Ice Shelf, and clearly show the ice cover and reflections from underlying layers. These are excellent results at such an early stage and are a tribute to the hard work of the entire CryoSat community,” said Prof. Duncan Wingham, CryoSat’s Lead Investigator.

First  data received
First data received

The satellite is in a polar orbit, reaching latitudes of 88°. This orbit brings it closer to the poles than earlier Earth observation satellites, covering an additional 4.6 million sq km – an area larger than all 27 European Union member states put together.

CryoSat-2’s sophisticated instruments will measure changes at the margins of the vast ice sheets that lie over Greenland and Antarctica and in the marine ice floating in the polar oceans. By accurately measuring thickness change in both types of ice, CryoSat-2 will provide information critical to scientists’ understanding of the role ice plays in the Earth system.

“The combined ground teams proved the value of months of extensive training and preparation and the satellite has shown to be a high-quality machine with very few problems. The launch and orbit injection have been almost flawless and we are looking forward to an extremely productive mission,” said Richard Francis, ESA’s Project Manager for CryoSat-2.

ESA's ice mission
ESA’s ice mission

With LEOP complete, ground experts will now put CryoSat-2 through an exhaustive commissioning phase lasting several months, during which the systems on board the satellite and on the ground will be optimised to provide the best-ever ice thickness data from space.

“We are very happy with the first calibration results from SIRAL. The data are now being processed and made available almost immediately to the commissioning teams. We are now optimising the data-processing system and results will be released once we have accumulated enough data,” said Tommaso Parrinello, ESA’s CryoSat mission Manager.

Marking a significant achievement for ESA’s Earth observation programme, CryoSat-2 is the third of its Earth Explorer satellites to be placed in orbit, all within a little over 12 months. CryoSat-2 follows on from the Gravity field and steady-state Ocean Circulation Explorer (GOCE) mission, launched in March 2009, and the Soil Moisture and Ocean Salinity (SMOS) mission, launched last November.

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50 thoughts on “CryoSat passes first operational tests

  1. This satellite has unprecendented precision, and so we’ll be able to get an accurate photo of the situation in the polar regions. But the lifetime of this satellite is said to be 3 or 4 years, so I don’t see how it will be possible to infer longterm trends from its data.

  2. The issue with this is that unless they begin with a fresh starting point there is no way to analyse anything. I would therefore presume that the intention is to monitor the ice as of now and any changes that occur subsequently, or are they just going to hide/exaggerate the decline?

  3. let’s all hope that the likes of Pachauri and Jones and WWF do not start calling the good folks who operate this satelite. It will all become a huge waste.

  4. And as soon as the first real reports come in, a host of “synthetic” ice measurements for the past 150 years will be released, all of which will purport to show just how much thinner the ice is now than it has *ever* been before!
    But at least this will establish a verifiable baseline for the future.

  5. With proper adjustments to the data you can provide supporting evidence for any agenda. The accuracy depends on the group evaluating the data

  6. RE: wws (09:35:28) :
    (snip)
    But at least this will establish a verifiable baseline for the future.
    This is of course dependant upon the code in the programming and the intrepretation of incoming data WRT how Melt Ponding will be considered as either sea level or water above sea level.

  7. “CryoSat-2’s radar altimeter is able to measure the freeboard of sea ice…”
    As a canoeist, I love this.

  8. pgosselin (09:22:41) :
    This satellite has unprecendented precision, and so we’ll be able to get an accurate photo of the situation in the polar regions. But the lifetime of this satellite is said to be 3 or 4 years, so I don’t see how it will be possible to infer longterm trends from its data.

    My reading of ESA’s release is that they are not at all interested in long term trends:
    “CryoSat’s original objective was to determine if there was a trend towards diminishing ice cover. There now seems little doubt that there are indeed trends – the challenge now is to characterise them.”
    http://www.esa.int/esaLP/ESAOMH1VMOC_LPcryosat_0.html
    And in order to “characterize” the diminishing ice cover, “CryoSat-2’s sophisticated instruments will measure changes at the margins of the vast ice sheets that lie over Greenland and Antarctica and in the marine ice floating in the polar oceans.”
    The objectives of this mission appear to me to be extremely narrow, and so will their findings be.

  9. If the thinness is good for AGW theory, the cry will be: “See, we told you.”
    If the thickness is bad for AGW theory, the cry will be: “There’s something wrong with the satellite.”
    Place your bets.

  10. Original Mike (10:14:14) :
    “CryoSat-2’s radar altimeter is able to measure the freeboard of sea ice…”
    As a canoeist, I love this.
    ——————
    Reply:
    Me too–I have four of the craft. However, it got me to thinking, if I were sitting in one of my canoes and this thing went over, how could it infer my weight by measuring my canoe’s freeboard unless they knew what kind of canoe I was paddling. (The freeboard shapes are diffierent for all four of my craft.) Hmmmmm…

  11. Well I hope it is able to figure out how thick all that buckled and piled up ice is.
    Am i correct in assuming that this sea ice grows in the same fashion as epitaxial deposition works, so those slabs of ice, whose freeboard will be measured are perfectly flat top and bottom; so fromt he freeboard and the 9/10 or 10/11 ratio you can find the total thickness from top to bottom all over the complete sheet; totally marvellous.
    It’s a long time since I did any elementary mechanics (statics); but if I remember correctly, since ice is less dense that sea water, the center of mass of the ice must be above the center of pressure; so those ice floes are inherently unstable, and during the course of their lifetime, they must do a whole lot of tipping; speaking of tipping; so I don’t see how they could in fact grow as a plano parallel layer of ice.
    Ergo, they can’t be cosntant thickness throughout.
    So what is it that the freeboard height is going to tell us again ?
    Enquiring minds want to know.
    But hey; I’m sure glad it is all apparently working properly. Congratulations to the team.

  12. I’d like to point out that the mission duration might well not be 3-4 years. In a similar position, NASA will routinely declare a 3 yr mission, with hardware designed for a minimum of 5 years. This serves two purposes. First, NASA can declare a “successful” mission after only 3 years and will still look good even if the hardware fails prematurely at 4 years. This type of consideration is very important for bureaucrats. Second, they need include only the costs of data support and processing for 3 years in their initial budget requests, which makes the mission appear more palatable to the funding agencies. If the mission survives the 3 years, then they’ll go back and request money for an “extended mission”. Everything I know suggests that the same type of considerations apply in ESA also.

  13. As stated in the Climate Change 2007 Synthesis Report by the Intergovernmental Panel on Climate Change, “Satellite data since 1978 show that annual average Arctic sea-ice extent has shrunk by 2.7% per decade.”

    There’s the given. Now we just have to “characterize” the trend. In 1000 days.

  14. Zeke the Sneak (10:22:53) And those margins we can forecast will be receding (during summertime, of course). It looks that everything has been decided in advance. We are the ones to be fooled, because WE ARE the fools and they the sages, so let us cheer them with lots of bubbling- CO2 and Coffee energized – kool-aid.

  15. I wonder what will happen when CryoSat produces data that refutes AGW wrought shrinkage of polar ice caps? Can we ask the EU for our extorted climate taxes back?

  16. pgosselin (09:22:41) :
    This satellite has unprecendented precision, and so we’ll be able to get an accurate photo of the situation in the polar regions. But the lifetime of this satellite is said to be 3 or 4 years, so I don’t see how it will be possible to infer longterm trends from its data
    But after 4 years the ice will all be gone, so there will not be a need for this sat.

  17. Hopefully, they think, there is enough inertia in the oceans to keep the good ice melt going so that the clarion call for AGW Carbon-Cash Syphoning System in Nashville and Washington, and Wall Street get’s an irreversible head of steam on it. The gig ends when the ice returns to ‘normal’ but not before the Satellite ends operations. Standby for annoying headlines.

  18. The participating Governments in this project all have a AGW agenda, like the Governments this satellite represents its agenda is basis.

  19. Pretty cool, but,
    How in the WORLD can they establish a “trend” with a satellite that only lives for 4 years? This is barely enough time to work out baselines and methods.

  20. Hmm, I wonder if they’ll publish anything at all if the data contradicts the consensus mantra… Perhaps they will, since a 4 year dataset is easily discarded by climaxologists. On the flip side, if the ice is found to be evaporating, I’m sure the results will be warmly embraced. With all the scrutiny, and pressure to perform, they are experiencing difficulty maintaining the warming mood. Perhaps a bit of ice, in just the right places, will help keep the wilting thermometers upright.

  21. enneagram (10:51:32) :
    And those margins we can forecast will be receding (during summertime, of course).

    You don’t think it could actually be worse than 2.7% per decade shrinkage…do you?!? 🙂

  22. @RockyRoad: Good question. Canoe freeboard varies from the design (as well as the load). Ice shape probably doesn’t vary as much as canoe shape. Or maybe they’re just interested in the freeboard and not making judgements about the amount of ice below the surface.

  23. Freeboard n.
    1. Nautical The distance between the water line and the freeboard deck of a ship.
    2. The distance between normal water level and the top of a structure, such as a dam, that impounds or restrains water.
    3. The distance between the ground and the undercarriage of an automobile.
    Provided for any other confused head-scratchers out there. 😉

  24. Original Mike (11:36:11) : There will be an assumed ice density. This will allow them to create, from the freeboard, the total mean ice thickness. Of greater concern to me is how they’ll calibrate this thing in the presence of melt ponds. I can’t imagine that they’d use the Caitlin “expedition” results …… !!! Hopefully they’ve gotten enough experience with AMSRE to have a handle on things. Anybody have any insights?

  25. The satellite probably operates by sending a radar pulse in its nadir direction, essentially normal to the surface of the water/ice. Two reflections will be returned, one from the ice and one from the water. If the ice has variations in its vertical contour, this will result in a spread in return pulse duration. The water, being “flat” (except possibly for waves), should give a tighter return signal. The time delay between the mean strengths of the two returns should correspond to the vertical separation between the ice and the water. Due to the fixed density difference of ice vs. water, the freeboard so found will be directly proportional to the average ice depth beneath the water. (What counts really is ice volume, but if the profiles are averaged, it works out to be depth.) And I expect this can “work” only at the margins of the ice pack, because that is where the ice-water juxtaposition is most reliably found. (The method would work over water leads in pack ice, but the returns would be dominated by the ice signal, and probably would be less accurate on account of that.)

  26. What other sources of data have we to verify the accuracy of this satellite? Despite proclaiming success right out of the bag, I’ll remove the truckload of salt when I see some repeated confirmation of specific areas on the ground.
    This instrument must do more than simply measure sea level at the fringes of an icefield, and compare to the levels within the ice field, like a simple gps experiment.
    But is it realistic to expect an accurate reading of an ice field 100% covered that is hundreds of miles across? Or will there be complicated algorythms to interpolate and fill in data…

  27. “”” MikeP (12:31:53) :
    Original Mike (11:36:11) : There will be an assumed ice density. This will allow them to create, from the freeboard, the total mean ice thickness. Of greater concern to me is how they’ll calibrate this thing in the presence of melt ponds. I can’t imagine that they’d use the Caitlin “expedition” results …… !!! Hopefully they’ve gotten enough experience with AMSRE to have a handle on things. Anybody have any insights?
    13
    04
    2010
    Michael J. Dunn (12:45:32) : “””
    That makes sense to me; maybe they can scan the ice surface which would obtain a mean surface level, and then the buoyancy thing would yield the total ice volume; wish I’d thought of that.

  28. It’s ESA which is intrinsically bound up with the EU. If it’s EU then it’s a campaign of lies and deceipt to promote their own favoured agenda…
    http://www.esa.int/esaCP/SEMFEPYV1SD_index_0.html
    So I expect nothing from this except propagandised out-pourings designed to promote the EU agenda i.e. AGW with shrinking polar ice and everything else green that sucks in order that they can control us and tax us – in that order…
    I hope I’m wrong but I’m not holding my breath…

  29. And don’t forget the ice is covered by snow. The US IceSat 2 (planned for 2015) will carry both radar for freeboard + laser so that the snow depth can be determined as well. In addition, IceSat is planning for Imaging so that location will be perfect.
    Cryosat will use “modelled” snow cover in its calculations. We all know how that goes.

  30. “We are very happy with the first calibration results from SIRAL.”
    I find that I can’t read this without wondering how the scientists’ preconceived ideas might affect the “calibration” of this instrument. And I’m pissed off at the lot of them for making me wonder.

  31. @ Michael J. Dunn (12:45:32) :

    The satellite probably operates by sending a radar pulse in its nadir direction, essentially normal to the surface of the water/ice. Two reflections will be returned, one from the ice and one from the water. If the ice has variations in its vertical contour, this will result in a spread in return pulse duration. The water, being “flat” (except possibly for waves), should give a tighter return signal.

    @ Glenn (13:32:07) :

    But is it realistic to expect an accurate reading of an ice field 100% covered that is hundreds of miles across? Or will there be complicated algorythms to interpolate and fill in data…

    Michael – is this scan going to be one slice across the ice? There are irregularities in all directions, so I want to ask if it is getting the reading over the entire ice area? Does it need to? I wouldn’t think one pass is good – it could be reading a low area or a high area, and how would it know? Is it going to assume that on the average 50% of all the scans are in low areas and 50% high and that averages out okay in large populations?
    Is there any wave action under large ice sheets? Many films of the open ocean shows large swells. Do these swells exist under pack ice? If so, will they be taken into account? An ice sheet is often larger than the peak-to-peak of swells. If the swells exist around the pack ice, do they also exist under it? Again, is it assumed the average of all scans will read 50% swells and 50% swales, so that on average it is okay in large enough populations of readings?
    Near shorelines does the wave action create wave turbulence? Does this affect the level of the ice? The water around the ice certainly will not be flat in all cases. Winds and currents will “complex up” the picture.
    While in principle this sounds like such a straightforward comparison, in practice it seems like there are a lot of variations in conditions to take into account.
    In engineering I have a rule of thumb that says:

    The time and effort and complexity of any project or question will be inversely proportional to the time it takes to voice the question.

    BEWARE of short and apparently simple questions.

  32. Okay, so it can measure how high the ice is floating. Does rotten ice float lower or higher? Anyone? Anyone? Bueller? Anyone?

  33. I posted this comment on the earlier thread: let’s not pre-judge. If the trend from the last three years of increasing ice extent continues, maybe data from this satellite will provide the final nail in the coffin of AGW.

  34. Mustafa Mohatarem (19:37:16) :
    Don’t be so naive.
    This satellite will continue to report the ice thinning, just like ICESat did:
    http://www.arctic.noaa.gov/reportcard/seaice.html
    Sea ice age and thickness
    Then when the normal Arctic ice extent takes a plunge this summer,
    http://arctic-roos.org/observations/satellite-data/sea-ice/observation_images/ssmi1_ice_area.png
    down past 2009 levels, or 2008 levels, or even 2007 levels,
    they will just say “that’s because the ice was so thin”.
    Hello!
    This satellite is microwaving the ice, orbit after orbit after orbit!
    Try putting an ice cube in your microwave for 1 minute – this satellite will be microwaving the ice for 4 years!
    Why do you think the AGW crowd was so eager to launch this satellite right after ICESat died ?

  35. What is everyone worried about? I’m sure Hansen et al will be able to come up with the perfect Homogenization factors.

  36. I can see how thickness measurements would work on free floating ice out in open water but how does it deal with compacted ice in the Beaufort Sea for example?

  37. Mike P, John Walker et al.:
    Ice shape shouldn’t matter much, but ice denisty does. In Greenland, you’re dealing with ancient ice which has been under extreme pressures for millennia. Some icebergs literally explode as they release pent-up gasses. There is a color scheme for Greenland icebergs, I believe green is the oldest, and some of the colors are quite spectacular. Some of the pressures involved in the interior probably approach something like the pressure at the base of the ice dam in Lake Missoula, i.e., exotic high-pressure forms of matter, neither solid nor liquid.
    ESA is pro-AGW, completely. This CryoSat project seems to be over doubts in NASA’s methodology for measuring ablation of the Greenland icecap via telemetry and mascon sensing from discrete sats. I couldn’t make heads nor tails of NASA’s methodology on this, they call it “stripping out extraneous mass” to arrive at a value for the GL icecap, but it doesn’t make any sense to me how they did it.
    The trend in GL seems to be warmer at sea level in the south (Cape Farewell even had some grass winter-over this year) but colder with more precipitation up on the ice. This doesn’t equal net ablation. All the media spectacles involving “lubrication” underneath glaciers that historically do what they’re doing right now, and the seasonal water floes that open large drain holes on the cap, are just that, media spectacles.
    It’s embarrassing for Denmark to have the facts on the royal territory of Greenland cast in so much doubt. Denmark is 100% behind AGW of course, with very little political or academic opposition.
    Not to belittle the measurments for Antarctica, I did notice Raytheon Polar Services at South Pole Station or McMurdo were gearing up for incoming CryoSat2 data.
    tl;dr: “freeboard” might work on new sheet ice free floating, but will probably give skewed data for ‘bergs because assumptions about density aren’t true. ESA does EU PNS, don’t expect much.

  38. One thing not mentioned yet is knowledge of the geoid, i.e. the vertical location of “mean sea level” will vary spatially based on localized changes in the gravity field. Thus if you are measuring any respectable distance from a sufficiently wide lead with open water, you will need knowledge of the geoid to interpolate. Even with a “repeating orbit” (possibly +/- 1 km cross track variation),there will be limitations to knowledge of the mean as aliasing will bias partially known oceanographic and tidal signals into the mean. Plus, you will only get estimates of sea level when you can observe the sea through a lead. It’s not clear to me how long you’d have to keep measuring to get a sufficient amount of unbiased data. It would seem that there would be a seasonal variation in open water and so seasonal steric changes would be biased into the mean also.
    So really, you must have at least the following models: snow cover, melt pond coverage, ice density, geoid, seasonal steric height changes, and tides. If any of the models are poor, then the quality of the ice volume estimates will be similarly poor. I don’t think that you can assume that errors will average out over the entire Arctic region. Some will, some won’t.
    Anything else?

  39. In response to Feet2theFire (17:16:47)—
    I confess I am not an expert on how Cryosat is implementing its sensor, but am making straightforward assumptions based on my experience in dealing with the general topic of radar.
    The cartoon graphic may be misleading in that it implies some kind of scanning plane moving across the ice/water field. This is not consistent with the actual physics of radar. What is more likely is that the Cryosat will send a radar pulse directly downward from its overhead position. This means the radar pulse wavefront will be similar to a gigantic pancake; it will hit a large area (perhaps square kilometers in extent) and some of it will reflect from the ice, while the rest of it will reflect from the water. All the satellite will be able to determine is the timing delay between the two reflected returns, to measure the freeboard as I mentioned previously. Necessarily, the returns will be averages over the area under the pulse. As the beam “footprint” moves across the ice field with the motion of the satellite, successive “cookie-cutter” radar hits can be had. They may even overlap, which can allow some detail to be determined by comparing adjacent pulse returns.
    Wave action is a phenomenon that occurs on a free surface. By definition, it cannot occur beneath a floating object (though wave turbulence might persist beneath). Whatever the wave action may be doing to the ice, the radar pulse will be so fast, it will be like high-speed photography catching the rugby player in mid-leap.
    Must now go to a meeting, but I hope the above is helpful.

  40. Europe….launching “CONVENIENT” satellites while economically collapsing. No Social justice anymore?

  41. Michael J. Dunn (08:51:23) :
    Wave action is a phenomenon that occurs on a free surface. By definition, it cannot occur beneath a floating object (though wave turbulence might persist beneath).

    Now I’m confused. What’s surfing all about then?

  42. I for one am glad that Cryosat 2 was successfully launched. Any measurements that get at the total ice volume on the planet are very important and this has been largely unknown over large spatial and temporal coverage because until ICESat scientists only had submarine sonar (in the Arctic Ocean) and individual mass balance estimates at glaciers and ice sheets. The way forward is to monitor ice thickness changes globally (because really, extent doesn’t give you the full picture).

  43. what’s the “freeboard” of slushy sea ice? what’s the “freeboard” of sheet ice when two or more layers hump and scatter back the radiation like multiple sea levels? I can’t really see this working to measure sea ice at all. there are tides, there’s the problem of inconstant gravity, there’s the geometry problem of flatish crystals on a spherical surface, and there’s constant motion in the sea ice and with icebergs turning over dramatically as they melt. it might shed some light on land ice though, if they do it right.

  44. Dear “Z”,
    Surfing is a situation where the surfer is small flotsam compared to the scale of the wave. Size matters. But there has to be a free surface (the boundary between air and water) for the wave to occur.
    Mike

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