ESDU 17008 gives a detailed account of the principles of laser-Doppler anemometry (LDA). Both the Doppler and fringe models are described. Guidance is given on component and configuration selection (including optical-access requirements) for applications, in various media, where 1D, 2D or 3D measurements are required. Flow seeding methods are described, together with setting-up and calibration procedures and signal processing. Emphasis is given to the safety requirements associated with laser operation. Flow charts are provided to help determine if LDA is appropriate for a given application and to aid configuration selection. ESDU 17008 should be read in conjunction with the introductory Data Item, ESDU 16001. ESDU 17008 and its associated Data Items deal with a wide range of flow-measurement applications but are also appropriate to specialised applications, such as wind-tunnel testing.