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The galactic bulge is a significant part of our galaxy, but it is hard toobserve, being both distant and covered by dust in the disk. Therefore there donot exist many hi-res optical spectra of bulge stars with large wavelengthcoverage, whose determined abundances can be compared with nearby, similarlyanalyzed stellar samples. We aim to determine the, for chemical evolutionmodels, so important alpha elements of a sample of bulge giants using hi-resoptical spectra with large wavelength coverage. The abundances found will becompared to similarly derived abundances from similar spectra of similar starsin the local thin and thick disks. In this first paper we focus on the Solarneighborhood reference sample. We use spectral synthesis to derive the stellarparameters as well as the elemental abundances of both the local as well as thebulge samples of giants. Special care is taken to benchmark our method ofdetermining stellar parameters against independent measurements of effectivetemperatures from angular diameter measurements and surface gravities fromasteroseismology. In this first paper we present the method used to determinethe stellar parameters as well as the elemental abundances, evaluate them, andpresent the results for our local disk sample of 291 giants. When comparing ourdetermined spectroscopic temperatures to those derived from angular diametermeasurements, we reproduce these with a systematic difference of +10 K and astandard deviation of 53 K. The spectroscopic gravities are reproducing theones determined from asteroseismology with a systematic offset of +0.10 dex anda standard deviation of 0.12 dex. When it comes to the abundance trends, oursample of local disk giants is closely following that of other works analyzingsolar neighborhood dwarfs, showing that the much brighter giant stars are asgood abundance probes as the often used dwarfs.

Abundances of disk and bulge giants from hi-res optical spectra: I. O, Mg, Ca, and Ti in the Solar neighborhood and Kepler field samples