Comparing the change in voltage by a factor of two as the temperature changes is a good way to check the similarities in array materials. Here, for the linear array, we have a ~6.5888 degree difference in temperature for every factor of two increase or decrease in voltage current. The values used to determine this are highlighted by bold borders in the above image.
Here, the difference is ~11.438 degrees. There is a ~4.8 degree difference between the arrays!
It is possible that the linear arrays are made from a slightly different batch of InXGaX-1As. Since we are measuring the values of a single pixel, we should not be experiencing something that is particular to the physical setup of the array (i.e. linear or planar). Also, the responsive temperature range of the linear array is larger than that of the planar.