# SRTM1S resolution **URL:** \ **Category:** Q&A\ **Created:** [July 23, 2023, 12:26am UTC](https://forum.generic-mapping-tools.org/t/srtm1s-resolution/4137 "2023-07-23T00:26:33Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![MahmoudMagdy0](https://avatars.discourse-cdn.com/v4/letter/m/6bbea6/32.png) [@MahmoudMagdy0](https://forum.generic-mapping-tools.org/u/MahmoudMagdy0)\ **Post date:** [July 23, 2023, 12:26am UTC](https://forum.generic-mapping-tools.org/t/srtm1s-resolution/4137/1 "2023-07-23T00:26:33Z")
when I plot a small area using SRTM1S the resolution is very good, but for large areas it becomes worse, and the size of the output file get smaller. How to keep the highest resolution? here the output images: [https://drive.google.com/drive/folders/12GxFPClmZTbBer1muqvczb8wJAdmqaKB](https://drive.google.com/drive/folders/12GxFPClmZTbBer1muqvczb8wJAdmqaKB) ---
**Author:** ![EJFielding](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/ejfielding/32/82_2.png) [@EJFielding](https://forum.generic-mapping-tools.org/u/EJFielding)\ **Post date:** [July 23, 2023, 12:51am UTC](https://forum.generic-mapping-tools.org/t/srtm1s-resolution/4137/2 "2023-07-23T00:51:57Z")
Please post the script you are using. There are several parameters that can affect output resolution. ---
**Author:** ![MahmoudMagdy0](https://avatars.discourse-cdn.com/v4/letter/m/6bbea6/32.png) [@MahmoudMagdy0](https://forum.generic-mapping-tools.org/u/MahmoudMagdy0)\ **Post date:** [July 23, 2023, 1:44am UTC](https://forum.generic-mapping-tools.org/t/srtm1s-resolution/4137/3 "2023-07-23T01:44:37Z")
gmt begin 1sec png gmt grdimage 1sec.nc -JJ20c -Cearth -B -I+d gmt end show first: I downloaded some .jp2 files second: converted them to .nc then combined them using grdblend and get the final grid (1sec.nc) finally: I tried to plot it using the attached script ---
**Author:** ![MahmoudMagdy0](https://avatars.discourse-cdn.com/v4/letter/m/6bbea6/32.png) [@MahmoudMagdy0](https://forum.generic-mapping-tools.org/u/MahmoudMagdy0)\ **Post date:** [July 23, 2023, 5:33am UTC](https://forum.generic-mapping-tools.org/t/srtm1s-resolution/4137/4 "2023-07-23T05:33:13Z")
I think I got it: It is about the dimensions of the out image, when I increased the scale in -J option the resolution become better and the out file size increased. Is that right? ---
**Author:** ![pwessel](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/pwessel/32/30_2.png) [@pwessel](https://forum.generic-mapping-tools.org/u/pwessel)\ **Post date:** [July 23, 2023, 7:26am UTC](https://forum.generic-mapping-tools.org/t/srtm1s-resolution/4137/5 "2023-07-23T07:26:23Z")
I fail to understand why you list the first, second, third etc since GMT does all that under the hood. E.g., gmt grdimage @earth\_relief\_02m -Cgeo -B -R20/25/24/26 -pdf map Changing the scale gives a larger plot but not improvement in resolution. Your post is a bit thin on the actual commands you run, so cannot help based on that. ---
**Author:** ![MahmoudMagdy0](https://avatars.discourse-cdn.com/v4/letter/m/6bbea6/32.png) [@MahmoudMagdy0](https://forum.generic-mapping-tools.org/u/MahmoudMagdy0)\ **Post date:** [July 23, 2023, 5:22pm UTC](https://forum.generic-mapping-tools.org/t/srtm1s-resolution/4137/6 "2023-07-23T17:22:38Z")
Because for resolution 5m and better I got some errors. I tried to delete cache files and rerun but nothing changes. I do not know if GDAL affects that. ```auto grdblend [NOTICE]: Remote data courtesy of GMT data server oceania [http://oceania.generic-mapping-tools.org] grdblend [NOTICE]: SRTM15 Earth Relief at 02x02 arc minutes reduced by Gaussian Cartesian filtering (3.8 km fullwidth) [Tozer et al., 2019]. grdblend [NOTICE]: -> Download 60x60 degree grid tile (earth_relief_02m_p): S30E000 grdconvert [ERROR]: File C:/Users/Right was not found grdconvert [ERROR]: Cannot find file C:/Users/Right grdconvert [ERROR]: Option -G: Given more than once (offending option is -GC:/Users/Right) grdconvert [ERROR]: Specify only one output file grdconvert [ERROR]: Specify only one input file grdblend [ERROR]: ERROR - Unable to convert SRTM file C:/Users/Right Click/.gmt/server/earth/earth_relief/earth_relief_02m_p/S30E000.earth_relief_02m_p.jp2 to compressed netCDF format grdblend [ERROR]: Unable to obtain remote file @S30E000.earth_relief_02m_p.nc grdconvert [ERROR]: File C:/Users/Right was not found grdconvert [ERROR]: Cannot find file C:/Users/Right grdconvert [ERROR]: Option -G: Given more than once (offending option is -GC:/Users/Right) grdconvert [ERROR]: Specify only one output file grdconvert [ERROR]: Specify only one input file grdblend [ERROR]: ERROR - Unable to convert SRTM file C:/Users/Right Click/.gmt/server/earth/earth_relief/earth_relief_02m_p/S30E000.earth_relief_02m_p.jp2 to compressed netCDF format grdblend [ERROR]: Cannot find file @S30E000.earth_relief_02m_p.nc grdconvert [ERROR]: File C:/Users/Right was not found grdconvert [ERROR]: Cannot find file C:/Users/Right grdconvert [ERROR]: Option -G: Given more than once (offending option is -GC:/Users/Right) grdconvert [ERROR]: Specify only one output file grdconvert [ERROR]: Specify only one input file grdblend [ERROR]: ERROR - Unable to convert SRTM file C:/Users/Right Click/.gmt/server/earth/earth_relief/earth_relief_02m_p/S30E000.earth_relief_02m_p.jp2 to compressed netCDF format grdblend [ERROR]: Cannot find file @S30E000.earth_relief_02m_p.nc grdblend [ERROR]: File @S30E000.earth_relief_02m_p.nc not found [Session gmt (0)]: Error returned from GMT API: GMT_FILE_NOT_FOUND (16) grdimage [ERROR]: ERROR - Unable to produce blended grid from C:\Users\RIGHTC~1\AppData\Local\Temp/=tiled_211_PX_a22328 [Session gmt (0)]: Error returned from GMT API: GMT_GRID_READ_ERROR (18) [Session gmt (0)]: Error returned from GMT API: GMT_GRID_READ_ERROR (18) [Session gmt (0)]: Error returned from GMT API: GMT_GRID_READ_ERROR (18) ``` ---
**Author:** ![Joaquim](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/joaquim/32/16_2.png) [@Joaquim](https://forum.generic-mapping-tools.org/u/Joaquim)\ **Post date:** [July 23, 2023, 5:43pm UTC](https://forum.generic-mapping-tools.org/t/srtm1s-resolution/4137/7 "2023-07-23T17:43:48Z")
> [@MahmoudMagdy0](#): > > `File C:/Users/Right was not found` People never believe when we warn the to **do not use spaces in file names (directories included)** I bet that you have a directory called “Right _or-wrong_” ---
**Author:** ![MahmoudMagdy0](https://avatars.discourse-cdn.com/v4/letter/m/6bbea6/32.png) [@MahmoudMagdy0](https://forum.generic-mapping-tools.org/u/MahmoudMagdy0)\ **Post date:** [July 23, 2023, 7:40pm UTC](https://forum.generic-mapping-tools.org/t/srtm1s-resolution/4137/8 "2023-07-23T19:40:07Z")
Ok I will change it, thank you.