# Plot data on Map with GMT.jl

**URL:** <https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937>\
**Category:** New to Julia\
**Tags:** plotting, gmt\
**Created:** [May 27, 2021, 3:11pm UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937 "2021-05-27T15:11:47Z")\
**Posts on this page:** 15\
**Page:** 1

<div class="post-metadata">

**Author:** ![mixstam1453](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mixstam1453/32/23731_2.png) [@mixstam1453](https://discourse.julialang.org/u/mixstam1453)\
**Post date:** [May 27, 2021, 3:11pm UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/1 "2021-05-27T15:11:47Z")

</div>

Hi everyone,  
I want to plot an 180x360 array on the Earth surface with coastlines. I know how to do it pycalling Cartopy, but i found GMT.jl interesting and usefull, but a little bit difficult to understand it as i am new on it.

# 1) plot data without coastlines , without correct lats!

```julia-auto
A=rand(180,360) # make the array
grdimage(A, fmt=:png,show=true) # plot it 

```

 ![GMTjl_2](https://global.discourse-cdn.com/julialang/original/3X/f/5/f53b6388ee63071f64a36eeef64813453b789304.png)

# 2) plot data with coastlines, without correct lats!

```julia-auto
grdimage(A)    
coast!(region=[0 360 -90 90],show=true)   

```

 ![GMTjl_3](https://global.discourse-cdn.com/julialang/original/3X/2/6/26023ae9f579d584d190361b113017188827d978.png)

# 3) plot only the HALF data in Robinson projection ( Northern Hemisphere) :

```julia-auto
 A=rand(90,360) # grdimage doesn't want to plot A=rand(180,360)
topo = makecpt(color=:rainbow, range=(0.1,0.9,0.05), continuous=true);
grdimage(A, coast=true,proj=:Robinson, frame=:a, color=topo,show=true)

```

 ![GMTjl_1](https://global.discourse-cdn.com/julialang/original/3X/8/6/86084b184e1622a05d6a6c45532f8fc88c00aed9.png)

######## 4) i want to plot my data in this figure:

```julia-auto
coast(region=(-180, 180, -90, 90), 
    proj=(name=:Robinson, center=0),
    resolution=:crude,
    land=:white, water=:white, area=7000,figsize=15,
    shore=:thinnest,
    frame=(annot=45, grid=45,ticks=45),
    fmt = :jpg,show=true)

```

 ![GMTjl_4](https://global.discourse-cdn.com/julialang/original/3X/8/9/89dc8573d59c9539029cacd94b31bdf84352793c.jpeg)

but i have no idea how to do it, in order to take all the latitudes correct…  
Also, is there any way to do it with Plots.jl ? I didn’t find some way do it yet without errors, even with VegaLite, GeoMakie, GadFly, PlotlyJS…  
Thanks for your time,  
Michael

---

<div class="post-metadata">

**Author:** ![joa-quim](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/joa-quim/32/227_2.png) [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Post date:** [May 27, 2021, 6:06pm UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/2 "2021-05-27T18:06:01Z")

</div>

Hi, thanks for trying it but won’t you prefer to plot something more colorful meaning than random noise? _e.g._

```julia
grdimage("@earth_relief_01d", region=(-180,180,-90,90), coast=true, fmt=:png, show=true)

```

 ![GMTjl_tmp](https://global.discourse-cdn.com/julialang/original/3X/a/e/aedc3cc481e52931e3efe9aa32de0e71a7db7667.png)

Note, you can’t make maps of Earth (or any other planetary body) without providing coordinates. `rand(180,360)` is just an array of numbers and `grdimage` just plotted in function of matrix size. To use your own data that does not come from known file formats (a very high number of them is recognized automatically) you must use the [GMT.jl types](https://www.generic-mapping-tools.org/GMT.jl/dev/types/). See docs for functions [mat2grid](https://www.generic-mapping-tools.org/GMT.jl/dev/#GMT.mat2grid), [mat2img](https://www.generic-mapping-tools.org/GMT.jl/dev/#GMT.mat2img) and [mat2ds](https://www.generic-mapping-tools.org/GMT.jl/dev/#GMT.mat2ds) that help to quickly convert your data into the needed form.

See also [Some examples · GMT](https://www.generic-mapping-tools.org/GMT.jl/dev/examples/#And-the-%22Hello-Round-World%22) for an example on how to plot data on maps. GMT itself has also many examples that look much nicer (and way less scaring) when using the `GMT.jl` wrapper.

---

<div class="post-metadata">

**Author:** ![mixstam1453](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mixstam1453/32/23731_2.png) [@mixstam1453](https://discourse.julialang.org/u/mixstam1453)\
**Post date:** [May 28, 2021, 10:23am UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/3 "2021-05-28T10:23:57Z")

</div>

Hi, congratulations for the package!  
Thank you for your instructions.  
I found that my problem was in mat2grid with incorrect x and y.  
Finally i plot a 360x180 grided array of outgoing solar radiation, with Robinson projection:

```julia
B= Array(q[:,:,1]) # q is a ClimArray (by using ClimateBase), 180x360, but the lats are from 89.5 to -89.5
B=Array(B') # transpose the array in order to get 360x180
B=reverse(B, dims = 2) # make the lats to be from -89.5 to 89.5
G2 = mat2grid(B , x=collect(0.5:1:359.5), y=collect(-89.5:1:89.5)) # x are the lons, y the lats

coast(region=(-180, 180, -90, 90), 
    proj=:Robinson,figsize=16,frame=(annot=45, grid=45,ticks=10)) # make the map
topo = makecpt(color=:rainbow, range=(0,225,20), continuous=true) #make colorbar
grdimage!(G2, coast=true,color=topo,
          frame=(annot=45,grid=45,title="CERES OSR")) # plot my gridarray
colorbar!(pos=(anchor=:BC,length=(12.5,0.6), horizontal=true, offset=(0,1.0)),
          color=topo, frame=(ylabel="W/m^2",), fmt=:jpg, show=true) # plot colorbar

```

 ![GMTjl_6](https://global.discourse-cdn.com/julialang/original/3X/f/5/f5b73fbb7b7ed06b9c19e69f5d2fcd1e3214ab7c.jpeg)

Now i will looking for :  
how to plot a text outside of the map (inside the map i do: text!([“Hello World”], x=92.0, y=30.0) ) ,  
the color of title and text and  
how to make the size of figure larger ( when figsize=30, some part of the right side of map is cutted…).  
Thanks again!!

---

<div class="post-metadata">

**Author:** ![rafael.guerra](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rafael.guerra/32/216610_2.png) [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Post date:** [May 28, 2021, 11:43am UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/4 "2021-05-28T11:43:06Z")

</div>

@mixstam, could you please edit your posts to include code inside ``` triple-backticks. See guidelines [here](https://discourse.julialang.org/t/psa-make-it-easier-to-help-you/14757). Thanks.

**NB:** _are you using Linux or Windows?_

---

<div class="post-metadata">

**Author:** ![mixstam1453](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mixstam1453/32/23731_2.png) [@mixstam1453](https://discourse.julialang.org/u/mixstam1453)\
**Post date:** [May 28, 2021, 12:09pm UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/5 "2021-05-28T12:09:22Z")

</div>

@ [rafael.guerra](https://discourse.julialang.org/u/rafael.guerra) Thank you. I use Linux, Kubuntu.

---

<div class="post-metadata">

**Author:** ![joa-quim](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/joa-quim/32/227_2.png) [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Post date:** [May 28, 2021, 12:57pm UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/6 "2021-05-28T12:57:09Z")

</div>

OK, the image size issue first. This is something I must work more and at least document better. What happens is that by default we start with an A4 page size which the best for me that almost always do the visualization in PostScript. For all the other formats the page size is increased automatically but that it’s too late when the default output format is PS.  
Short, for the moment, declare an environment variable called “JULIA\_GMT\_IMGFORMAT” and set it to `"png"`. E.g., **before** starting GMT do

`ENV["JULIA_GMT_IMGFORMAT"] = "png";`

or after `using GMT`

`GMT.FMT[1] = "png"`

Now the text. Here the issue is that you want to plot the text _somewhere in the universe_. That is, outside the plot domain and that it’s not possible if you use the geographical coordinates. What you have to do is to start a new plot domain but this time using paper coordinates. Something like

```julia
text!(["Hello World"], region=(0,30,0,30), proj=:linear, x=15, y=15) 

```

and you may have to add a `figsize=...` if the default one does not fit with previous plot.

---

<div class="post-metadata">

**Author:** ![mixstam1453](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mixstam1453/32/23731_2.png) [@mixstam1453](https://discourse.julialang.org/u/mixstam1453)\
**Post date:** [May 31, 2021, 8:17am UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/8 "2021-05-31T08:17:59Z")

</div>

Hello, have a good week.  
Thanks again.  
I plot my text well,

 ![GMTjl_rob](https://global.discourse-cdn.com/julialang/original/3X/e/a/eadf437028128628fb5faaff16e21f95ab5156bd.jpeg)  
the code is here:

```julia

text(["mean = 170 W/m^2"],figsize=30,frame=(annot=""),region=(0,30,0,30), proj=:linear, x=7, y=9 ,font=(10,:red)) 
text!(["20 May 1994"],frame=(annot=""),region=(0,30,0,30), proj=:linear, x=1, y=9 ,font=(10,"Palatino-Italic",:darkgreen)) 
text!(["Outgoing Solar Radiation at TOA"],angle=7, frame=(annot=""),region=(0,30,0,30), proj=:linear, x=13, y=9.2 ,font=(10,"Courier-Bold",:purple))

coast!(region=(-180, 180, -90, 90), 
    proj=:Robinson,figsize=16,frame=(annot=45, grid=45,ticks=10)) # make the map
topo = makecpt(color=:rainbow, range=(0,225,20), continuous=true) #make colorbar
grdimage!(G2, coast=true,color=topo,
          frame=(annot=45,grid=45,title="CERES OSR")) # plot my gridarray
colorbar!(pos=(anchor=:BC,length=(12.5,0.6), horizontal=true, offset=(0,1.0)),
          color=topo, frame=(ylabel="W/m^2",), fmt=:jpg, show=true) # plot colorbar

```

but about the size of the image i can’t fix it with `GMT.FMT[1] = "png"` or `ENV["JULIA_GMT_IMGFORMAT"] = "png";` , because when i execute this and then plot:

```julia
grdimage(G2, figsize=(30,14),coast=true,color=topo,frame=(annot=45,grid=45,title="CERES OSR")) # plot my gridarray

```

I get the larger size but when i try then colorbar!() or coast!() or text!() (something with !) i get this error:

```julia
julia> colorbar!(pos=(anchor=:BC,length=(12.5,0.6), horizontal=true, offset=(0,1.0)),             
                 color=topo, frame=(ylabel="W/m^2",), fmt=:jpg, show=true) # plot colorbar        
Error: /undefined in A
Operand stack:
   0
Execution stack:
   %interp_exit .runexec2 --nostringval-- --nostringval-- --nostringval-- 2 %stopped_push --nostringval-- --nostringval-- --nostringval-- false 1 %stopped_push 1990 1 3 %oparray_pop 1989 1 3 %oparray_pop 1977 1 3 %oparray_pop 1833 1 3 %oparray_pop --nostringval-- %errorexec_pop .runexec2 --nostringval-- --nostringval-- --nostringval-- 2 %stopped_push --nostringval--
Dictionary stack:
   --dict:728/1123(ro)(G)-- --dict:0/20(G)-- --dict:75/200(L)--
Current allocation mode is local
Current file position is 9647080
psconvert [ERROR]: System call [gs -q -dSAFER -dNOPAUSE -dBATCH -sDEVICE=bbox -DPSL_no_pagefill -dMaxBitmap=2147483647 -dUseFastColor=true '/tmp/GMTjl_tmp.ps' 2> './psconvert_71425c.bb'] returned error 256.
ERROR: Something went wrong when calling the module. GMT error number =
Stacktrace:
 [1] error(s::String)
   @ Base ./error.jl:33
 [2] gmt(::String)
   @ GMT ~/.julia/packages/GMT/wprG1/src/gmt_main.jl:289
 [3] showfig(d::Dict{Symbol, Any}, fname_ps::String, fname_ext::String, opt_T::String, K::Bool, fname::String)
   @ GMT ~/.julia/packages/GMT/wprG1/src/common_options.jl:2951
 [4] finish_PS_module(d::Dict{Symbol, Any}, cmd::Vector{String}, opt_extra::String, K::Bool, O::Bool, finish::Bool, args::GMT.GMTcpt)
   @ GMT ~/.julia/packages/GMT/wprG1/src/common_options.jl:3101
 [5] finish_PS_module(d::Dict{Symbol, Any}, cmd::String, opt_extra::String, K::Bool, O::Bool, finish::Bool, args::GMT.GMTcpt)
   @ GMT ~/.julia/packages/GMT/wprG1/src/common_options.jl:3028
 [6] colorbar(cmd0::String, arg1::Nothing; first::Bool, kwargs::Base.Iterators.Pairs{Symbol, Any, NTuple{5, Symbol}, NamedTuple{(:pos, :color, :frame, :fmt, :show), Tuple{NamedTuple{(:anchor, :length, :horizontal, :offset), Tuple{Symbol, Tuple{Float64, Float64}, Bool, Tuple{Int64, Float64}}}, GMT.GMTcpt, NamedTuple{(:ylabel,), Tuple{String}}, Symbol, Bool}}})
   @ GMT ~/.julia/packages/GMT/wprG1/src/psscale.jl:85
 [7] #colorbar!#358
   @ ~/.julia/packages/GMT/wprG1/src/psscale.jl:93 [inlined]
 [8] top-level scope
   @ REPL[596]:1

```

Similar error i get even if i code:

```julia
text(["mean = 170 W/m^2"],figsize=30,frame=(annot=""),region=(0,30,0,30), proj=:linear, x=7, y=9 ,font=(10,:red)) 
text!(["20 May 1994"],frame=(annot=""),region=(0,30,0,30), proj=:linear, x=1, y=9 ,font=(10,"Palatino-Italic",:darkgreen)) 

```

```julia
julia> text!(["20 May 1994"],frame=(annot=""),region=(0,30,0,30), proj=:linear, x=1, y=9 ,font=(10,"Palatino-Italic",:darkgreen))                  
Error: /undefined in A
Operand stack:
   0
Execution stack:
   %interp_exit .runexec2 --nostringval-- --nostringval-- --nostringval-- 2 %stopped_push --nostringval-- --nostringval-- --nostringval-- false 1 %stopped_push 1990 1 3 %oparray_pop 1989 1 3 %oparray_pop 1977 1 3 %oparray_pop 1833 1 3 %oparray_pop --nostringval-- %errorexec_pop .runexec2 --nostringval-- --nostringval-- --nostringval-- 2 %stopped_push --nostringval--
Dictionary stack:
   --dict:728/1123(ro)(G)-- --dict:0/20(G)-- --dict:75/200(L)--
Current allocation mode is local
Current file position is 20857
psconvert [ERROR]: System call [gs -q -dSAFER -dNOPAUSE -dBATCH -sDEVICE=bbox -DPSL_no_pagefill -dMaxBitmap=2147483647 -dUseFastColor=true '/tmp/GMTjl_tmp.ps' 2> './psconvert_71425c.bb'] returned error 256.
ERROR: Something went wrong when calling the module. GMT error number =
Stacktrace:
 [1] error(s::String)
   @ Base ./error.jl:33
 [2] gmt(::String)
   @ GMT ~/.julia/packages/GMT/wprG1/src/gmt_main.jl:289
 [3] showfig(d::Dict{Symbol, Any}, fname_ps::String, fname_ext::String, opt_T::String, K::Bool, fname::String)
   @ GMT ~/.julia/packages/GMT/wprG1/src/common_options.jl:2951
 [4] finish_PS_module(::Dict{Symbol, Any}, ::Vector{String}, ::String, ::Bool, ::Bool, ::Bool, ::GMT.GMTdataset{Float64, 2}, ::Vararg{Any, N} where N)
   @ GMT ~/.julia/packages/GMT/wprG1/src/common_options.jl:3101
 [5] finish_PS_module(::Dict{Symbol, Any}, ::String, ::String, ::Bool, ::Bool, ::Bool, ::GMT.GMTdataset{Float64, 2}, ::Vararg{Any, N} where N)
   @ GMT ~/.julia/packages/GMT/wprG1/src/common_options.jl:3028
 [6] text(cmd0::String, arg1::GMT.GMTdataset{Float64, 2}; first::Bool, kwargs::Base.Iterators.Pairs{Symbol, Any, NTuple{4, Symbol}, NamedTuple{(:frame, :region, :proj, :font), Tuple{String, NTuple{4, Int64}, Symbol, Tuple{Int64, String, Symbol}}}})
   @ GMT ~/.julia/packages/GMT/wprG1/src/pstext.jl:127
 [7] text(txt::Vector{String}; x::Int64, y::Int64, first::Bool, kwargs::Base.Iterators.Pairs{Symbol, Any, NTuple{4, Symbol}, NamedTuple{(:frame, :region, :proj, :font), Tuple{String, NTuple{4, Int64}, Symbol, Tuple{Int64, String, Symbol}}}})
   @ GMT ~/.julia/packages/GMT/wprG1/src/pstext.jl:144
 [8] #text!#370
   @ ~/.julia/packages/GMT/wprG1/src/pstext.jl:146 [inlined]
 [9] top-level scope
   @ REPL[598]:1 

```

To enlarge image size it is not my issue for now, but generally i would like to know how to achive this in future. I really appreciate your prompt responses and GMT.jl has a lot of features for further study.

Cheers,  
Michael

---

<div class="post-metadata">

**Author:** ![joa-quim](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/joa-quim/32/227_2.png) [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Post date:** [May 31, 2021, 11:20am UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/9 "2021-05-31T11:20:32Z")

</div>

Thanks. Opened [an issue](https://github.com/GenericMappingTools/GMT.jl/issues/617) to track this. Diagnosis is done but need to come out with a solution.

---

<div class="post-metadata">

**Author:** ![joa-quim](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/joa-quim/32/227_2.png) [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Post date:** [May 31, 2021, 5:09pm UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/10 "2021-05-31T17:09:28Z")

</div>

OK, the problem is hopefully solved but solution for now lives only on the master branch. It also now defaults to _png_ so no more need to use the environment variable (unless you want to change the default to _e.g._ _pdf_)

Note, you can use `region=:global` and `frame=:none` instead of `region=(-180, 180, -90, 90)` and `frame=(annot="")`

---

<div class="post-metadata">

**Author:** ![mixstam1453](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mixstam1453/32/23731_2.png) [@mixstam1453](https://discourse.julialang.org/u/mixstam1453)\
**Post date:** [June 1, 2021, 7:21am UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/11 "2021-06-01T07:21:26Z")

</div>

Hi,that works !  
Firstly `]add GMT#master`  
Here is the code with the larger figure size:

```julia
text(["mean = 170 W/m^2"],figsize=50,frame=:none,region=(0,50,0,50), proj=:linear, x=18, y=27 ,font=(18,:red)) 
text!(["20 May 1994"],frame=:none,region=(0,50,0,50), proj=:linear, x=37, y=27 ,font=(18,"Palatino-Italic",:darkgreen)) 
text!(["Outgoing Solar Radiation at TOA"],angle=-7, frame=:none,region=(0,50,0,50), proj=:linear, x=43, y=25.8 ,font=(18,"Courier-Bold",:purple))

coast!(region=:global, 
    proj=:Robinson,figsize=50) # make the map
topo = makecpt(color=:rainbow, range=(0,225,20), continuous=true) #make colorbar
grdimage!(G2,coast=true,color=topo,
          frame=(annot=30, grid=30,ticks=10,title="CERES OSR"),par=(FONT_ANNOT_PRIMARY=18,)) # plot my gridarray
colorbar!(pos=(anchor=:BC,length=(32.5,0.7), horizontal=true, offset=(0,1.0)),
          color=topo, frame=(ylabel="W/m^2",),par=(FONT_ANNOT_PRIMARY=18,), show=true,savefig="/home/michael/Desktop/gmt1.png") # plot colorbar & show and save figure

```

The figure size now is 50 and i also enlarge the font of annotations with `par=(FONT_ANNOT_PRIMARY=18,)`

 ![gmt1](https://global.discourse-cdn.com/julialang/original/3X/0/e/0eceb758bce994f4597cd9ca73a5357717306bf7.png)

Many thanks!  
Cheers,  
Michael

---

<div class="post-metadata">

**Author:** ![joa-quim](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/joa-quim/32/227_2.png) [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Post date:** [June 1, 2021, 11:28am UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/12 "2021-06-01T11:28:42Z")

</div>

Cool and thanks for pushing me to do this fixes.

One thing on your plot. You are plotting the coastlines twice. First with the `coast!` command and then again with the `coast=true` option of `grdimage`. Furthermore the first coastlines plot is hidden by the next image plot. You may skip the call to `coast!` and move its options to `grdimage` where they are the same.

---

<div class="post-metadata">

**Author:** ![joa-quim](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/joa-quim/32/227_2.png) [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Post date:** [June 1, 2021, 3:28pm UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/13 "2021-06-01T15:28:16Z")

</div>

@mixstam1453 A curiosity question. What is this _Outgoing Solar Radiation at Top of Atmosphere_? First I thought in ground reflection but looking at the image pattern it does not make much sense.

---

<div class="post-metadata">

**Author:** ![mixstam1453](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mixstam1453/32/23731_2.png) [@mixstam1453](https://discourse.julialang.org/u/mixstam1453)\
**Post date:** [June 1, 2021, 3:53pm UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/14 "2021-06-01T15:53:51Z")

</div>

Is the solar radiation that finally reflected back to the space (from clouds, aerosols and earth’s surface). The CERES project provides satellite-based observations of this. It is conceptually useful to think of the altitude at about 100 kilometers above the Earth as the “top of the atmosphere.”

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**Author:** ![joa-quim](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/joa-quim/32/227_2.png) [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Post date:** [June 1, 2021, 4:04pm UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/15 "2021-06-01T16:04:24Z")

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Thanks. On the back of my mind was a question on if this data could be useful to do better atmospheric correction of satellite images. But it would need to be on a per wavelength basis, not total radiation.

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**Author:** ![mixstam1453](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mixstam1453/32/23731_2.png) [@mixstam1453](https://discourse.julialang.org/u/mixstam1453)\
**Post date:** [June 2, 2021, 7:41am UTC](https://discourse.julialang.org/t/plot-data-on-map-with-gmt-jl/61937/16 "2021-06-02T07:41:00Z")

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Yeah, i don’t study the satellite images but possibly it is necessary per wavelength basis for the correction.