The z=0 galaxy luminosity function. I. Techniques for identification of dwarf galaxies at similar to 10 Mpc

We present a program to study the galaxy luminosity function of the Leo I a nd Coma I Groups at similar to 10 Mpc. We have surveyed over 7 deg(2) in Le o I and similar to 11 deg(2) in Coma I. In this paper, we detail the method we have developed and implemented for identifying on morphological grounds low surface brightness, M-R < -10, dwarf galaxies at a distance of 10 Mpc. We also describe extensive Monte Carlo simulations of artificial galaxies, which we use to tune our detection algorithms and evaluate our detection e fficiency and parameter recovery as a function of R-band central surface br ightness <mu>(R)(0) and total magnitude R-T. We find for a subset of our Le o I data that at the 90% completeness level, we can detect dwarfs comparabl e to Antlia and Sculptor. Finally, we describe preliminary follow-up observ ations that confirm we are detecting dwarf spheroidal galaxies in Leo I at 10 Mpc.