The AMSR2 Antenna has been Successfully Deployed

May 18th, 2012 by Roy W. Spencer, Ph. D.

UPDATE: AMSR2 has been successfully spun up to its initial spin rate of 4 rpm (it will later be spun up to 40 rpm for normal operations). It will take 45 days for the Shinzuku satellite to be maneuvered into the A-Train satellite constellation; about 3 months for complete instrument checkout.

Now this is a real treat…the first on-orbit image I am aware of taken from the spacecraft of an Earth-observation instrument ON the spacecraft itself (all imagery courtesy of JAXA).

The first image is an artist’s rendering of the Japanese Shizuku satellite (aka GCOM-W) with the location of the camera indicated:

The second is an actual photo from that camera of the AMSR2 instrument after its antenna has been deployed from its stowed position:

I’m not sure of the schedule regarding when calibrated data will start flowing operationally. The calibration design of AMSR2 has been improved, and I’m sure JAXA will want to be pretty confident of their calibration before data are released. Then, the algorithms which convert the calibrated data into products such as sea ice parameters and SST will have to be tested.

Well before those events happen, though, I’m sure we will see some “first light” imagery from the instrument.

A variety of Shizuku photos and artist renderings are available here.

11 Responses to “The AMSR2 Antenna has been Successfully Deployed”

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  1. RW says:

    Great news. So can we expect highly accurate SST measurments from this once it’s fully calibrated and ready for operation?

  2. Dan Murray says:

    I’m wondering if the enthusiasm evident in Dr. Spencer’s post over this new data source is shared by his detractors.

  3. bob paglee says:

    Great news! More scientific data will be welcome fodder for the debates to follow.

    And regarding debates,I wish to offer my congratulations to you for winning the very interesting one in which you participated during lunchtime at the Heartland Climate Conference in Chicago earlier this week!

  4. bob paglee says:

    For those who may have missed it here’s a link to that excellent debate– but I don’t know how long it will remain active:

    • Massimo PORZIO says:

      Thank you Bob for the link.
      I missed it, and despite my problems in understanding the English language I would compliment with Dr.Denning and Dr.Spencer for their clear way to spell out which allowed me to follow their arguments.
      Anyways I would like to know Dr.Spencer point of view about the latest Dr.Denning’s statement regard to the spectroscopic measurement of the CO2 absorptance in laboratory.
      By my point of view the absorption isn’t the important parameter for the GHGs atmospheric energy retain analysis, but their diffused transmittance instead. That because absorptance is the characteristic of a gas to transform the radiant energy into one other (usually heat). In that case why should we worry about it? Since CO2 is just a trace gas and it shares its energy with all the other dominant gases (even if they are not GHGs) in that case the presumed 4W/m^2 absorbed power due to the doubling is diluted over the atmospheric column by thermodynamic effects, and not fully reflected to the Earth surface. If I’m not wrong, when we talk about AGW we always refer to the very few meters over the ground not the whole column.
      In fact, to simulate the spectroscopic view of the satellites, MODTRAN computes the transmittance not the absorptance.
      What I still don’t realize is if the spectroscopic analyses used to model the GHGs behaviors in that simulation takes account of the very difference between diffused and regular transmittance.
      That is: is the satellites’ on board spectrometer field of view wide enough to “see” the whole outgoing radiation?
      Or better, are they designed to get the diffuse transmittance or the regular one?
      If I didn’t misunderstand him, in that video Dr.Spencer was not so confident with that 4W/m^2 of retained power per CO2 doubling.

      Have a nice day.


      • RW says:

        Interesting insights. One of things I appreciated from Dr. Roy was his clarification to Scott and the audience that the 4 W/m^2 per CO2 doubling from radiative transfer calculation/simulation is only a “theoretical measurement” (from average concentrations of GHGs). In my experience, it seems far too many people do not understand this and for whatever reason think it’s somewhow equivalent to a direct laboratory measurement.

        Also, in my experence, there seems be a lot of muddled notions as to what exactly is being calculated in these RT simulations. It’s my understanding that what is being calculated are changes in direct surface radiation to space for changes in GHG concentrations, or in the case of CO2, the reduction in direct surface radiation to space upon an instantaneous CO2 doubling. That is when CO2 is doubled, the atmosphere absorbes an additional 4 W/m^2 of surface radiative power that was previously passing directly into to space the same as if the atmosphere wasn’t even there.

        • Massimo PORZIO says:

          Hi RW,
          first of all I want to tell you that I’m not a scientist, I’m just an engineer so may be I’m wrong in what it follows.
          Anyways, when you write “That is when CO2 is doubled, the atmosphere absorbes an additional 4 W/m^2 of surface radiative power that was previously passing directly into to space the same as if the atmosphere wasn’t even there.”
          It’s my opinion that it could not be so, because that value is the very same computed by MODTRAN doubling the CO2 content of the atmosphere column. Since MODTRAN has been thought by the US Air Force for simulate what is seen by the forward looking IR sensors through the clouds, there is no doubt that doubling the content of CO2 a FLIR sensor will see that 4W/m^2 reduction at abt 670cm-1, but a FLIR sensor is not useful to estimate how much energy is passing through the atmospheric layer where it is placed. That because it has a very directive field of view. A FLIR sensor can’t see all the energy which passes that layer with angles out of its field of view which is very narrow. I don’t want to bore someone here, because I already referenced this work before in this blog, but if you google this: “First spectral measurement of the Earth’s upwelling emission using an uncooled wideband Fourier transform spectrometer” you get a pdf document wrote by some Italian scientists. On page 4076 (don’t worry, the document starts at page 4061 indeed), you can see figure 3 which shows you how at abt 34km of altitude the outgoing radiation which is tangent to the atmosphere measured by the spectrometer had a peak exactly where at the nadir the same spectrometer measured the presumed CO2 absorption. What I’m arguing is that doubling the content of CO2 into the atmospheric column, the absorption pit at 670cm-1 increases of about 4w/m^2 (I’ve no doubts about that), but at the same time that peak of energy that exits the atmosphere almost tangent to it should increase too. This should make the effective retained energy flux less than the presumed 4W/m^2.

          Have a nice day.


  5. Kasuha says:

    It’s great news to hear a new satellite has been deployed. I wonder how much controversy there will be “stitching” the new satellite measurements with the old satellite ones…

  6. nice nice i luv this one

  7. click here says:

    While I actually like this post, I believe there was an spelling error near towards the end from the 3rd sentence.

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