Level 2 Product Ver. 1.3 (006-06-0200) Release Notes
March 1, 2011
SMILES Office, Japan Aerospace Exploration Agency

1.

Descriptions

The version 1.3 is a fourth test retrieval version to verify L1B and L2 dataprocessing.
The version numbers for previous products have also been renamed, “1.0” forformer 005-06-24, “1.1” for 005-06-0032, “1.2” for 005-06-0150.

We request that the version 1.3 data should be used very cautiously for scientificpurposes, under the condition that you know characteristics of the data well.

The period of coverage of this version is from October 12, 2009 to April 20, 2010.
From November 30 to December 15, 2009, the ISS Solar Paddle stopped just infront of the SMILES IFOV due to the maintenance reason of the Port Solar
Power Module elements of the ISS.

From February 25 to March 5, 2010, the number of L1B data is only around
10% of ordinary condition, due to trouble of communication system of ISS/JEM(not according to SMILES itself).

There are two types of products. The one is consisted of minimum information(L2Product_G_RA, 0.8 MB/file), which is identical with the product of previousversion. In addition of it, the other has detailed information, such as the status flagfrom L1B and averaging kernels (L2Product, 8MB/file). Refer to the Product Guidefor details.

The pointing direction for determining tangent altitudes (geometrical) is calculated
by using SMILES scan mirror angle and ISS position. However, since the pointing
accuracy heavily would affect to error of tangent altitude determination, an average
altitude within single scan is retrieved with using the Star Sensor of SMILES in L2processing. In case that sunlight or moonbeam enters in the FOV of SMILES StarSensor, positioning information cannot be obtained, so it will be estimated from theinformation of 50 scans around the scan in such cases.

The tangent altitude for L2 data is retrieved as an elevation angle offset of antenna.



For the retrieval of Band C, a priori value of the tangent altitude is provided fromBand A or B. (There are operational modes with Band A+C and Band B+C.)

This version of L2 product includes some profiles which is inadequate for scientificuse. In using these products, it is strongly recommended to pick up usable profiles‐ 1 ‐according to the following conditions:
The L2 product might include the data of scan in case of antenna FOVinterference with ISS solar paddles, whose number is abouta few of all scans

in the product. We encourage to exclude the scans, which is under condition
that fovInterference > 0, from any data analysis. However, there is no forecast
data for FOV interference in about 7% of “antenna FOV interference” scan, so
it is difficult to exclude these scan data.
The converged profiles can be picked up with the condition of NumIterPerform> 3. The criterion is the most credible quality information,.About 85% of datafor band A, 75% for band B, and 50% for band C satisfy this criterion.

The nearly converged profiles can be picked up with the condition ofConvergence < 10. About 70% of data for band C meet this condition. However,a few scans of abnormal data per day might be included in each product.
L2 products includes altitude range not usable for validation and/or science. If theL2Precision is more than 50% compared to the AprioriError, it is probable that L2algorithm is just answering a priori. In this case, the value of L2Precision has been
turned into negative. (L2Precision and AprioriError are defined as HDF EOS5
names in the SMILES L2 products.)
Preliminary “status flag” has been newly added from this version.

Condition of vertical correlation is not introduced in the retrieval of all species
except temperature, according to the result of vertical correlation study.

2.

Improvements

L1B data have been updated from version 005 to 006. The retrieved profiles fromthe scans near “FOV interference” were improved by referring “the flags indicating
FOV disturbance.” For details of L1B data update, see the document “Level 1
Product Release Notes (Ver.006)”.

Standard temperatures for Lorentz width of absorption lines of O3, HNO3, HO2 andozone isotopes have been corrected from 300K to 296K. The effect for this correctionis around a few percent.

In correcting the tangent height on the observation point, it is introduced that theantenna elevation offset is retrieved from the average of altitude offset within one
scan. According to this change, O3 and HCl above 50km increase a few percent.

Antenna movement within the time to acquire a spectrum for single height is taken
into account with the antenna pattern. This improvement causes a few percent
increase of ozone at the peak height (lower stratosphere).
‐ 2 ‐



In order to make better fitting of the curved baseline of brightness temperature, theuncertainty of absorption coefficient is fitted with 2-dimensional function instead of
1-dimensional. As a result, residue of the baseline has been decreased to about ahalf in comparison with the previous version.

Regularization of status vectors in the inversion model with a priori error havebeen introduced. According to this improvement, 2-dimensional term of theabsorption coefficients with small number of digits can be retrieved.

The grids of retrieval altitude have been adjusted 2, 3 or 4 km depending on species,
band and altitude, instead of uniformly 3km in the previous version. In adjusting
the altitude grid, the information of altitude resolution is referred. As a result of
this modification, the species with high sensitivity (such as O3 and HCl) can beretrieved with more precise altitude grid, and the one with low sensitivity (such asBrO and HO2) can be retrieved with wider altitude range.

The altitude correlation of 10km has been introduced for all products except O3
from band A and B.

The information of convergence, FOV interference and observation altitude arestored in the status field. For details, see the format sheet in the Product Guide ofversion 1.3.

In order to evaluate the residue of spectrum, the cost function for all species and all
altitudes are stored in the CostFunctionY and CostFunctionYAll fields in theproducts.

Bugs in the AveragingKernel, InformationValue and VerticalResolution fields havebeen fixed.

3.

Remaining Issues after ver. 1.0(0024)/1.1(0032)/1.2(0150)



Correction factors of on-orbit AOS response function are experimentally obtained
from the retrieval result of temperature profiles. The new on-orbit measurement
data for AOS response function were obtained in January of 2011, and these data
are now under analysis. [Continuing from ver. 1.2]

HOCl, HNO3 (in band A) and BrO data (in band A) look not usable. [Continuingfrom ver. 1.0]

We recommend zonal mean processing on using CH3CN, BrO (in band C), HNO3 (inband C) and HO2 data.

Checking of O3 isotope products have not been sufficiently done yet. [Continuingfrom ver. 1.0]

‐ 3 ‐

4.

Newly Found Issue in ver. 1.3

Non-linearity of brightness temperature is not compensated in the version 006 ofL1B data, but the effect of this non-linearity seems to be serious. For example, afew Kelvin of temperature in the stratosphere, and 10% of ozone amount, can be
decreased with the compensation. We recognize this issue as the most important
problem. We continue our investigation in cooperation with SMILES instrument
team.

According to the change of retrieval altitude grid, altitude grids of the species insingle product are not uniform. In the future, we consider to apply the pressure
grids uniformly among the species. In addition, we are studying some
improvements of L2 retrieval algorithm.

‐ 4 ‐