i am not so sure weather this will solve your problem but  i hope you will find it helpful.

https://www.youtube.com/watch?v=kheo8xv3gdg

https://landsat.usgs.gov/gap-filling-landsat-7-slc-single-scenes-using-erdas-imagine-TM

https://landsat.usgs.gov/filling-gaps-use-scientific-analysis

https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&uact=8&ved=0ahUKEwi0neOa_ZnUAhUCS48KHW8GBbAQFgg_MAQ&url=https%3A%2F%2Fgis.stackexchange.com%2Fquestions%2F30250%2Fhow-to-fill-gaps-in-slc-off-landsat-7-etm-images-with-qgis&usg=AFQjCNFdfn4jLFxM4LHbuHWRFYIrVU5qvg&sig2=I1MbdH78qH3fINZlB11Ndg

https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&cad=rja&uact=8&ved=0ahUKEwi0neOa_ZnUAhUCS48KHW8GBbAQFghLMAY&url=http%3A%2F%2Fwww.mdpi.com%2F2072-4292%2F9%2F1%2F12%2Fpdf&usg=AFQjCNGEsfLqGoecfMDZe8qPnVykPgBb3A&sig2=_GkM0fEWiw59MZENnNVr4Q

https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&cad=rja&uact=8&ved=0ahUKEwi0neOa_ZnUAhUCS48KHW8GBbAQFghRMAc&url=http%3A%2F%2Fwww.jatit.org%2Fvolumes%2FVol63No1%2F16Vol63No1.pdf&usg=AFQjCNFe2Gm8GbbbpTKtIoiEhVB900s4eQ&sig2=rDAeARtEDYSXDFywJ1gRmw

https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=9&cad=rja&uact=8&ved=0ahUKEwi0neOa_ZnUAhUCS48KHW8GBbAQFghYMAg&url=https%3A%2F%2Fpdfs.semanticscholar.org%2F8e60%2F413d7a5bcdad61784aff34faebfb910e0805.pdf&usg=AFQjCNGikZ6Hsb2oqf6BBI-0Fv8C27Q9jg&sig2=xgawWS3bpIXpyPgbdRYgFA

https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&cad=rja&uact=8&ved=0ahUKEwi0neOa_ZnUAhUCS48KHW8GBbAQFghdMAk&url=https%3A%2F%2Fwww.intechopen.com%2Fdownload%2Fpdf%2F38452&usg=AFQjCNFobKyh7WNMXQwYvaXtidPQuueJkA&sig2=pgNlbQArP0LZvkcUiSae6w

Raju Thapa,

Thanks a lot for your detailed information. 

before your reply i found a toolbox which is employed in a youtube video:

https://www.youtube.com/watch?v=QbUXbdk6u7M

Can i use it for scientific purpose ? 

Best

Dear Majid

SLC tools for filling gaps calculated value of pixel. you need real pixel value for LST estimation. Most authors not used SLC algorithm, because they do not get the real pixel temperature value.

Dear Tea Duplančić Leder,

Thank you for your answer and guide

Best,

Dear Majid, you may consider the algorithm of gap filling (spatial analysis) in ERDAS Imagine.

alguien tendrá la herramienta de Gapfill para ArcGis 10.5

https://www.arcgis.com/home/item.html?id=e424afd2d30a427fbb8e614f0845ae31

Download this tool and select fix landsatscan line error

Dear Somayeh Amini ,

I found a toolbox to fill the gaps (or scan-lines) . After filling, I estimated the LST. I didnt estimate the LST of original images (it's recommended). So i have not compared the LST of original images and gap-filled images.

Where can I find Landsat 7 Scan Line Error correcting tool for Landsat Toolbox in ArcMap to download?

Gilbert Adjoyi

https://www.arcgis.com/home/item.html?id=e424afd2d30a427fbb8e614f0845ae31

Thank you Vetiya for the toolbox.

download landsat toolbox

I found this helpful

https://www.arcgis.com/home/item.html?id=e424afd2d30a427fbb8e614f0845ae31

thank you for solving my same problem!

Thanks. I helped me today.

Thanks for your help

Pls l need landsat tool box for arcgis 10.5