Did you ask yourself, which software has been used!!!
I think my above simple clarification already explains your question;
Once more, Do you use GAMMA S/W, or/and SNAP-StAMPS, then the right sign of subsidence and uplift is also has mentioned before is below once again,
Finally I have a message to all InSAR software engineers, in any next ESA related conference, hope to unify the subsidence, and uplift palette, Or ground movement representative palette.
For more clarification, because might be the junior researchers in some probability cases would understand the palette means the colors of the bar and the signs positive and negative, and actually Not, the following example explains more what I meant exactly of this phrase mentioned above with regard to unify the palette,
The core of InSAR techniques is measuring the distance between satellite and the objects on the ground or/and the ground, Let’s suppose the ground in the level zero, GAMMA S/W, and SNAP-StaMPS, calculate any movement towards satellite as an uplift and this represents an increase of the ground height from level zero, thus the sign is positive, on the contrary side any movement away from satellite means subsidence and ultimately it represents as a decrease of the ground height from the level zero and thus the sign is negative.
Other InSAR softwares, calculate the movement towards satellite or an uplift as a decrease of the distance between the ground or/and an object and the satellite, and then it has a negative sign, on the other hand the movement of the ground away from satellite or subsidence will increase the distance between both, and then it has positive sign.
Of course both are correct, unify the mathematical calculations of all software, and ultimately the palette will give the users and the clients of any company a good comprehensive idea of the actual process.