A previous question asked what the little metal plates between the horizontal and vertical stabilizer were (they are vortex generators), however I am much more interested in what the gray tube shaped structures are that go down the top quarter of the fuselage. What are they and what do they do? Are they sensors, countermeasure pods, something else?
The aircraft is the Indonesian Airforce Boeing 737-2X9 “Surveiller” aircraft, used for Maritime Patrol. The fairings house Side looking Airborne Radar for matitime surveillance. From b737.org:
Fitted with Motorola AN/APS-135(V) Side Looking Airborne Modular Multi-Mission Radar (SLAMMR) The antenna of which was mounted in two 16ft housings on the upper rear fuselage. This system could spot small ships at ranges of 100nm.
Indonesia Operates three of them- AI-7301, AI-7302 and AI-7303.