Some "smart" bombs require GPS, but not all. It's my understanding that certainly the US military (and thus one imagines the IDF) possesses the ability to interfere with the C/A code but not the P(Y)-code. This being the case it would be next to useless for Hamas to attempt to jam GPS (unless Israeli troops were carrying civilian GPS units for personal use), but advantageous for the IDF.
You're right, not all "smart" bombs require GPS. I assumed that the IAF is using JDAM smart bombs, which use IMU & GPS integration. I don't see why one should use infrared or laser-guided bombs when one can use JDAMs.
The IDF could interfere with the C/A code indeed. Since Hamas seems to use obsolete equipment, I honestly don't see what tactical advantages would the IDF gain from jamming the civilian GPS signal.
One uses laser-guided bombs for improved accuracy. The USAF has embarked on an LJDAM program to combine the fair condition accuracy of laser with poor condition performance of IMU/GPS in to a single weapon system.
Those laser-guided JDAMs require the target to be "illuminated" by laser until it is hit, right? If so, LJDAMs are not "fire & forget" kind of bombs, which is OK, since the IAF owns the sky over Gaza anyways.
Since the IAF wants to minimize the collateral damage (at least that's what they say), then LJDAMs would indeed make sense. I stand corrected.
Blocking commercial GPS would make a lot of sense if there are palestinian forward observers watching the maneuvers of the IDF on the ground and communicating the coordinates of the IDF units so they could be shelled by (precise) mortar fire.
