Image built vs google maps image

Q&A
1

google
google1200×710 209 KB
Hello All,

I have created an image using the following commands:
% grdimage grid_file.grd -JM${IMAGE_SIZE}c -R${MIN_LON}/${MAX_LON}/${MIN_LAT}/${MAX_LAT} -C${CPT_FILE_NAME}.cpt -K > ${IMAGE_NAME}.ps
% ps2raster -A -TG -E${IMAGE_DPI} ${IMAGE_NAME}.ps

Both built and google images have Mercator projection. It seems that the built one is a bit stretched in vertical direction, hence proportions of the bay are distorted.
Could anybody advice on how to fix this?

Thank you. Best regards.

test
test1182×2644 35.9 KB
test.ps (252.3 KB)
test
test1182×2644 35.9 KB

2

It’s difficult to help since your script only includes variables, and we have no idea of knowing what those are.

When I’ve had problems with stretching, it usually was solved by instead of specifying a width (e.g. -JM15c), specify a scale (e.g. -Jm1:10000).

3

Hello Andreas,

Thank you very much for your reply. I have cleared an automation script of everything non-gmt related. Please find attached archive, I hope you will be able to give an advise.

Best regards,
Dmitri

built_vs_google.zip (436.0 KB)

4

Hmm, all I did was to replace your -JM.. with -Jm1:10000, but that produces an identical plot (except for size). Are you sure that it’s not correct? Is there an error in your grid-file?

5

The grid is some 120 m offplace regarding WGS but other from it, no problems and we are sure grdimage and mercator projection are working fine.

image

6

Thank you very much, Joaquim!

7

Unfortunately there is. Thank you for your reply!

Best regards,
Dmitri

8

There is what?..