This is not a "Giraffe S 3D" radar, nor is it any type of 3D radar:
- "Giraffe S" is a 2D version of the Giraffe AMB (see e.g. this Master Thesis regarding mast development in collaboration with SAAB: http://publications.lib.chalmers.se/records/fulltext/134453.pdf )
- Giraffe AMB was developed in the late 1990s, so it's quite impossible to have been sold to the Singapore airforce in 1988 (see e.g. the timeline in this presentation provided to the Czech defence university: http://katalog.unob.cz/konferencepvo/data/uploads/2012/dvd.img/prezentace/08_mikas.pdf )
It is however most likely a Giraffe 75.
