
发表文章有不少步骤,走走停停,有时候会因为得到审稿人的赏识和认可开心不已,当然也会因为意见尖锐,无法修改而苦恼不已,下面我总结了一些例子,看看如何回答 review report 里面的问题,所有内容均是自己文章投稿的真实过程,希望对大家有所帮助。
1. 关于 Cover letter
整理了一份一般的格式,大体都是这样,呵呵
Dear Editor
Dr. Yinon Rudich Nov. 25, 2009
JGR
Manuscript Number: 2009JD013023,
“Gross primary production estimation from MODIS data with vegetation index and photosynthetically absorbed radiation in maize”
Enclosed is the revised version of the paper entitled “Remote estimation of gross primary production in maize, coniferous forest and grassland using MODIS images”. We appreciated the thorough reviews provide by the journal and the positive response of both two reviewers that found the research of this manuscript is suitable for JGR. Below is our response to their comments resulting in a number of clarifications.
Regards
Dr. Chaoyang Wu
**************
2. 关于 Response 细节
最根本的一个要求是事实就是,有什么说什么,不要企图遮遮掩掩,也不要回避,对意见一般先要礼节性的感谢或者同意,然后再做出修改。格式一般要求对不同的审稿人的意见作出一一回答,一定要细致,千万不要以为能够蒙混过关,自己把不能解决的问题删掉,这样的回复估计就要被拒掉了。还是老老实实的回答,即使暂时不能回答的,如一些方法改进之类的,委婉的说一下,如今后的实验会注意等等。 对于粗心的错误,自己就痛快承认了,没什么大不了的。哈哈,坦诚一点,给人的印象好一点。
下面是一个列子,希望能对大家有所帮助。
Manuscript Number: 2009JD013023
Manuscript Title: Gross primary production estimation from MODIS data with vegetation index and
photosynthetically absorbed radiation in maize
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Associate Editor (Remarks to Author):
Three reviewers provide reasonably consistent views about your manuscript, although their choices
of the category differ. I believe that the paper is worthy of publication in JGR as the correlations
between GPP and VIs are significant and could be useful for arid region crop growth estimation.
However, these empirical relationships would have limitations, and these limitations are not clearly
stated. In areas where radiation is variable, GPP may depend on not only vegetation greenness
but also meteorological variables. The limitations should be stated clearly in the revision. You
should revise your manuscript according to suggestions of these reviewers.
Response: We appreciate the positive comments about the manuscript. We also consider it is very
important and necessary to state the limitations of this method. With help of Prof. Anatoly Gitelson,
we decided to add a further validation of our method in forest and grassland ecosystems
in the manuscript. Although this decision was not suggested by the reviewers, we think that by
applying the method to the three species, our method can be better evaluated and compared with
other publications. This new validation part may also suggest some explanations to some concerns
of the review report. For example, the relationship between GPP and VI*VI*PAR shows species
specific. Regretfully, we did not get enough auxiliary data in the forest and grassland sites, and
these two sites are used for model validation. We can modify the manuscript just following the
suggestions in review report, but we think it will be better and more interesting by adding this part.
Reviewer #1 (Highlight):
The cross-product analyses of remotely-sensed VIs for improved GPP estimations in Maize fields.
Reviewer #1 (Comments):
Overall this is an interesting paper with some nice findings about cross-multiplying VI's to better
relate remotely sensed vegetation information with tower measures of GPP. The main weakness
is that there seems to be excessive use of "correlations" of many separate relationships which are
then combined. A more rigorous evaluation of the VI x VI approach would have been preferable
and more worthy. However, there are still interesting results presented.
My specific comments are as follows:
1. In the Abstract, PAR should be "...active radiation" and not "...absorbed radiation".
Response: we followed the suggestions.
2. The equation provided and used applies to "SAVI" and not "MSAVI".
Response: we changed the MSAVI to SAVI throughout the paper, including in the text and figures.
3. Note that Sims et al. (2006) had an earlier paper in which they utilized both NDVI (for fPAR) and
EVI in some combined fashion to predict GPP. This VI x VI case should be discussed and evaluated,
as this study has also tested the product (NDVI x EVI).
Response: we have tried to find the reference the reviewer suggested but failed. Instead, we think it may probably the paper of “A new model of gross primary productivity for North American
ecosystems based solely on the enhanced vegetation index and land surface temperature from
MODIS, RSE, 2008” which already listed in our reference. In that paper, a model (TG Temperature and Greenness) of EVI×LST was proposed for the estimation of GPP (below name Fig.6) because the MODIS LST correlated well with PAR (below name Fig.1). We find two more papers of Sims et al., 2006 (Parallel adjustments in vegetation greenness and ecosystem CO2 exchange in response to drought in a Southern California chaparral ecosystem, RSE and On the use of MODIS EVI to assess gross primary productivity of North American ecosystems, JGR), but no method of VI×VI was found. We think Our VI×VI approach validated TG model indirectly because we used the in situ measured PAR (in TG model, the LST was used as a proxy of PAR), the VI×VI constitutes a non-linear stretch of a single VI, increasing its sensitivity at high vegetation green biomass. We added some explanations in the discussion part.
4. In the Eddy covariance methods, there is no mention of what portion and what averaging of the
diurnal data was used in this study?
Response: we agree with this suggestion and provided more detail information about the EC and PAR
data used. First, we got the time of MODIS overpass time. Then five readings of NEE/T and 10
readings of PAR around the time were selected. The averaged values were used for GPP calculation.
5. In the MODIS methods section, how were the clouds and thin clouds identified and removed.
There should be mention of the use of MODIS quality assurance data information provided with the
MOD09 reflectances. There is no mention as to whether the 3x3 or 9 pixels were averaged.
Response: Yes, we added the method of cloud detection and relevant reference was also included.
Also the average values of nine pixels were averaged for later analysis.
6. Using MODIS LAI/fPAR product to derive an independent LAI- fPAR relationship is very questionable
and needs to be better assessed. In the first place, one should better define what was used, which may
have been MOD15 500m product. Secondly, for the aims of this study, the authors need to establish the
LAI- fPAR relationship with more independent, and maybe in-situ data, and not with satellite data, as
MODIS LAI/fPAR products are just more VIs and the fPAR product has been shown to have problems
in agriculture and other areas (just as stated in Xiao's and Zhang's papers). There is a lot of biophysical
information available over maize canopies (see Gitelson articles referenced), and the authors should first
evaluate use of MOD15 LAI/fPAR products through cross-comparisons with in-situ measurements from
maize fields. If the authors believe that MOD15 is suitable for use as is, then these 2 "indices" can
perhaps be directly used in their GPP model study, i.e., fPAR is directly available from satellite (MOD15),
so why not use this and avoid use of NDVI and EVI.
Response: we are very appreciated with these important suggestions by the reviewer and agree with this.
We made some corresponding changes in the manuscript and below are our clarifications. First, the
LAI-fAPAR relationship was used for calculation of LUE, which is a variable for cross validation of our
model. Due to the experiment design (see paper of Li et al., 2009, JGR, WATER experiment), some
biophysical information were not observed, especially the fAPAR. However, it will be important in our
paper to explore the potential of VIs in the estimation of both LUE and fAPAR. Therefore, we used an
indirect method to calculate these two variables. As suggested by the reviewer, we used the in situ
measurements of LAI (details of LAI measurement was also added) for fAPAR calculation with equation
of fAPAR=0.95(1-Exp (-0.5LAI)). This method demonstrated to be workable with other publications
(Ruimy et al., 1999; Xiao et al., 2004). The LUE was calculated by the following equation of
GPP=LUE*fAPAR*PAR, GPP were from EC measurements, fAPAR from in situ LAI, and PAR from
in situ meteorological measurements. We think that it was not appropriate to use MODIS product for
calculation.
7. Section 3.2. "...we displayed the NEE and T in the daytime when the MODIS data acquired..." Again,
the authors do not provide how "daytime" is defined and how NEE, GPP, PAR were averaged to generate
a daily comparison with the satellite. Have the authors considered that satellite overpass time varies day
to day across time zones (hourly intervals)?
Response: we added the data processing information in section 2.3 and the daytime here is the MODIS
satellite overpass time.
8. There needs to be a minimal level of aggregation of the fluxes in order to be able to compare with
satellite data, and the authors need to provide this information.
Response: we consider it is necessary to give more detail information about the data used. In section
2.3, with the MODIS overpass time, we used 5 readings of NEE around and 10 readings of PAR for
aggregation and averaged in later analysis.
9. Section 3.3. How were LUE values computed and derived? is this information provided?
Response: see our explanations with concerns of No.6.
10. Section 3.4.1. "NDVI had the least potential for LUE assessment in this paper as NDVI was largely
affected by background information..". There is no data nor bases to support this? NDVI may be affected
by different soils, but the authors did not establish that (1) there are soil variations of concern within this
study and (2) and that these were responsible for the poorer NDVI results.
11. Same applies to: "First, EVI is an index that can better overcome the background disturbances and
sky conditions than other indices." The authors have not shown that sky conditions were a factor in this
study and are merely guessing why the indices yield different results. As it was not objective of this
study, such interpretations should be removed from Results; although one is free to conjecture such
ideas in the Discussion section (so move such comments to discussion section).
Response: we checked throughout the manuscript and removed these parts into a new discussion part.
12. Conclusions section: "In this paper, our method worked well for the wheat that was a relatively
homogenous canopy," As far as I know this is a study about Maize
Response: We are sorry for this mistake.
13. There should be some error bars in Figs 3-5.
Response: we added the error bars as suggested.
14. It was annoying that no page numbers were used.
Response: page numbers were added in this revision.
Reviewer #2 (Comments):
This paper investigates the relationship between gross primary production (GPP) and four vegetation
indices (NDVI, EVI, MSAVI, and WDVI), using data from a maize site. Authors aim to seek a simple
relationship between GPP and vegetation indices, which is an important effort in linking satellite
observations with CO2 flux tower measurement. However, I have a number of concerns on the
manuscript.
1. English writing needs substantial improvement, and I would suggest that authors seek a help from a
native English speaker to work on it. The manuscript does not have page number and line number,
which makes it difficult to write comments for the manuscript. The reference citation in the text does
not follow JGR format.
Response: we got help from a native speaker to proofread the paper and the reference citations were
changed to follow the JGR format.
2. Page 2 Introduction: 1st paragraph needs to be re-written and expanded to include more scientific
justification on their study of GPP.
Response: we added more information about the GPP definition and current mechanism of GPP
estimation based on LUE model.
3. Page 4 literature review on the VPM model. Note that Yan et al., 2009 used the VPM model to simulate
GPP of both winter wheat and maize crop in a study site in North China. The paper might be of interest
to the authors.
Yan, H., Fu, Y., Xiao, X., Huang, H., He, H. and Yu, G., 2009, Modeling gross primary productivity of
winter wheat and maize double-cropping system, using MODIS time series imagery and CO2 eddy flux
data, Agriculture, Ecosystems and Environment, 129(4): 391-400.
Response: yes, we added this reference to give a better introduction of both VPM model and GPP
estimation.
4. Page 5. It mentioned " The LUE could be estimated by spectral VIs ..'. it needs to specify it.
Response: We added three VIs (PRI, NDSI and MTCI) as examples for LUE estimation to specify
the use of VIs.
5. Page 5 last paragraph, "The paper is organize as follows ...", it would read better if authors start it
in a new paragraph.
Response: we followed this suggestion in the manuscript.
6. Page 6. Section 2.1. It is too short, and needs to expand for providing more info about the site,
particularly vegetation and soils.
Response: additional information were added to better description of this site.
7. Page 6, Section 2.2, how frequently does LAI is measured?
Response: The LAI was measured everyday during the experiment time.
8. Page 7, section 2.4. Is the daily MODIS data used in the study? Is the MODIS onboard Terra or the
MODIS onboard Aqua satellite used? When 3x3 pixels (1.5km) are used? What is the fraction of maize
within the 1.5 km radius?
Response: we used the MODIS/Terra daily surface reflectance data in this paper. The 3x3 pixels were
used for calculation of reflectance covering the EC sites. In the maize site, the fraction of maize within t
he 1.5 km radius would be higher than 95% because only small ridges were inside. For forest and
grassland sites, the fraction could be almost 100%.
9. Section 2.5, page 7 - Page 8, it needs to expand and provide detailed description on how LUE was
calculated. Maize is a summer crop, why authors used data from 11/1/2007 to7/12/2008 to derive a
relationship between LAI and fapar?
Response: in section 2.5, we provided a more detail information of LUE and fAPAR determination.
Furthermore, we also consider it was not appropriate to use MODIS LAI/fAPAR product to derive
the relationship. Instead, we used a method suggested by reviewer1 to use the in situ measured LAI
for the calculation of fAPAR with equation of fAPAR=0.95(1-Exp (-0.5LAI)). This method demonstrated
to be workable with other publications (Ruimy et al., 1999; Xiao et al., 2004). The LAI used was data
in the same time of other observations.
10. Page 8, Section 2.6, authors need to specify what indices were used the work of Inoue et al. (2008).
Response: some VIs were added in the part to avoid confusion.
11. Page 10, Section 3.1, why only data (NEE and T) from 22:00pm to 3:00am next day are used in
calculated? The night time definition needs to revisit and authors should use appropriate definition of
night time? In short, authors need to provide much better and consistent way to describe how to
partition NEE data into GPP and ecosystem respiration.
Response: we added an explanation of nighttime selection. Because high altitude in western China,
sunlight time may from 05:00 to 21:00 in summer, therefore, we selected the time from 22:00 to
03:00 in the night to acquire the relationship of NEE/T.
12. Page 11, Section 3.3., Authors need to provide much more detailed information on how they
calculate LUE.
Response: information was added in section 2.5.
13. Page 12, section 3.4.1, while vegetation indices are correlated with LUE, it does not mean that one
can use vegetation indices to replace LUE. One must realize that vegetation indices and LUE are two
different terms and biological processes. In that same paragraph, authors also found good correlation
between vegetation indices and fapar.
Response: we agree with the suggestions by the reviewer, perhaps because we authors are not native
speakers, and we made mistakes in the use of “replace”. These VIs just could be indicators or proxies
of the variables. The revision will be proofread by a native speaker and we are trying to make it clear
and consistent.
14. Page 15, it stats "", if that is the case, what is the value of this paper? Does that relationship change
by biome? Or does that relationship change by pixel?
Response: the statement of “it seems unlikely there is a universal relationship of fapar or LUE to a VI”
is about the specific regression coefficients. Our mean is that a regression model (specific coefficients)
derived from maize ecosystems may not valid for other ecosystems. As many researches
(Gitelson et al., 2005, Chl estimation different for maize and soybean, GPL) indicated that different
ecosystems may act differently. Therefore, in the revision, although all reviewers did not suggested
to apply our method in other ecosystems, we decided to add a further validation part in the manuscript
to see if this method works in forest and grassland. As we did not get enough auxiliary data (LAI),
we just apply the model derived from maize for forest and grassland systems. We got clear difference
in regression and this result implies, first, our method may also work for forest and grassland, and
second, different species may affect the regression.
15. This manuscript only uses 1-month long CO2 flux data, and it does not cover the entire plant
growing season of maize. It is not sure how well the GPP equation would work in early and late part
of the maize growing season.
Response: We agree with this concern. Due to earthquake in China 2008, we could not get part of
the data, especially in the later mature season. Our experiments started from the beginning (3-4
leaves, 5cm in height) to a middle stage (about 1.8 m in height) of maize. Thus, the method may
work in the early stage. For the late, especially the senesces, more work will be needed. We will
continue this method in future research. We added some clarifications in the discussion part.
16. The linear correlation or regression analysis in this manuscript does show the usefulness of
vegetation indices, however, if a model does not include climate constraint, it is of no use to estimate
the effect of weather variation (e.g., temperature, water).
Response: Yes, we consider it’s right to concern more about the climate variables in the estimation of GPP. The linear correlation may be the most important findings in this study and is explained by Monteith logic. The main aim of the paper is trying to find a model that can use all inputs from remote sensing observations for GPP estimation as it will be helpful for crop growth evaluation as large areas, quickly and iteratively. However, this method has some limitations, for example, maybe can not track the seasonal changes. We added a new discussion part to better evaluate our method, especially for the limitations.
17. Figure 5, LUE values are very small. It does not make sense, when compared with other publications.
Response: we changed the unit of LUE (mol CO2mol-1PPFD) in the revised version so that this result
could be better compared with other literatures.
Reviewer #3 (Highlight):
I think that the theme is important because it can take advantage for other agronomical cultures using
MODIS data or other remote sensor.
Reviewer #3 (Comments):
Comments to manuscript:
1. The authors mention that R2 is the correlation coefficient, which is false because R2 talks
about the determination coefficient.
Response: we followed this suggestion and made changes throughout the paper.
2. Adapt the introduction to the work that they developed and not to mix introduction with methodology.
Response: we removed some part of method in section 2.1 as a new part of methodology.
3. They present acronyms that are not defined in the manuscript, and I suggest reviewing the writing
of this because in some paragraphs is confused.
Response: we checked throughout the paper and made corrections where needed.
4. In the variables that used they do not show the units in the manuscript and either in the title of the figures.
Response: we added the units of variables both in the text and in figures.
5. Change the color of some symbols of figures 6 to 8, because are not appraised well.
Response: we changed the color in figures.
6. There are orthographic errors and of writing in the text corrected them.
Response: we checked through the manuscript and made changes accordingly.
7. Some literature were not in the references and three references are not mentioned in the text.
Response: all references were checked for consistency.
8. If the authors wrote 22:00 p.m., then to correct 3:00 a.m. instead of 3.
Response: we followed this suggestion.
9. I consider that the period of study is very short and it is not possible to speak of seasonal changes
Response: Yes, we agree with the concern and provide more information about the stages of maize.
The limitations were also stated in the new discussion part.
10. They do not present discussions sufficient to support the results, and the figures little are taken
advantage of, is necessary to discuss more on the matter.
Response: we agree with this suggestion and we added a new part of further validation of our method
with additional discussions.
11. I think that the simple objective to estimate GPP derived from data MODIS is not sufficient and
makes lack as GPP modeled related to in situ data, as well as its variation.
Response: yes, we consider the in situ data (e.g., temperature, water content) would be more related
with the GPP and GPP models incorporating these variables may more logically be accepted by scientists.
Remote observations, such as MODIS and other sensor data, would be offering a method of GPP
evaluation quickly, nondestructively and timely in those cases where in situ data were impossible.
Recently, less dependent on input parameters becomes a momentum for development of new models
in GPP estimation. Much work has been done; for example, using VIs (Gitelson, IEEEL, Landsat;
Sims, 2008, RSE, MODIS). We are trying to find a model with less input variables. For example,
Sims et al., 2008 showed a model of GPP estimation with land surface temperature. On the other
hand, if we can find some indicators of LST from satellite observations, we may avoid using the
in situ measurements. Here is an explanation of the objective of the study, we are trying to use all
remote sensing data for GPP estimation. With Monteith equation, we used VIs for estimation of
both LUE and fAPAR. Estimation of PAR from satellite observations would be very helpful for
our method and this work is undergoing. However, we also know that this method do have limitations
in the operational application. These limitations were added in the discussion part of manuscript.
