1. Introduction  
2. Initial Feasibility Study  
3. Modelling Details  
3.1. X-ray Luminosity Functions  
3.2. Linear Bias Factors  
3.3. Photometric Redshift Model  
4. Angular Power Spectrum and Fisher Matrices  
4.1. Angular Power Spectrum  
4.2. Fisher Matrix  
5. Forecast Results  
5.1. Baryon Acoustic Oscillations  
5.2. Cosmological Parameters  
6. Discussion  
6.1. Comparison with Dedicated Cosmological Surveys  
6.2. Dependence on the Parameters of the All-Sky Survey  
7. Conclusions