Several factors can cause white patches in Landsat thermal bands B6/B10 images:

Dear Kunanayagam Thanuraj

Your missing data problem is probably due to cloud cover at the time of photo shot. You could try exploring other images taken at different times to verify this.

Might help if you included as Google Maps link to the Area of Interest and the granule number(s) you are dealing with. For instance if https://www.usgs.gov/landsat-missions/saturation-bits-parameter is occurring.

"Pixel saturation is common for TM and ETM+ (particularly in the visible bands). Digital numbers (DN) of 255 are reserved for designating saturated pixels in TM and ETM+. Pixels surrounding those with DN values of 255 are also affected by saturation.

Features likely to cause saturation include clouds, snow/ice, barren soil, and white sand. If band-specific pixel saturation is a concern for a specific application, the DN of the Landsat Level-1 data product should be used as confirmation."

Michael John Patrick Dorian M. Gaboriau John Desderius Kalimenze I appreciate the responses received regarding the white patches in Landsat images. However, in this case, the cloud locations and the white patches do not match. Instead, clouds appear as dark areas in Band 10(Landsat 8) and Band 6( Landsat 5,7). Additionally, the saturation status is "N." This issue is not for single image but all images that i have downloaded , with both B10 and B6 showing white patches and dark shadow .

I didn't have time to examine this in depth. But they don't seem to have any correspondence with what might be happening on the ground ( like a forest fire, etc. ... I'm not familiar with the area, but before, during, and after seasonal field burns can cause anomalies) or manifest in the visible bands. The scene is basically an extract of a strip, so you might look up and down the path to see if the artifacts are also appearing there. If it is data loss or sensor malfunction, sometimes these are logged ( example https://ladsweb.modaps.eosdis.nasa.gov/alerts-and-issues/163894 ).