The use of GNSS has expanded to mass market users and most of them are located in populated areas and roads where local environmental characteristics, which include buildings, trees, moving objects, etc., increase the multipath and the Non-Line-of-Sight (NLoS) effects, thus dominating the GNSS measurement errors. Also threats like radio frequency (RF) interference and spoofing can affect the positioning service. These local characteristics, which cannot be corrected by the ground or satellite segments, degrade the signals leading to potentially high positioning errors and therefore may also hinder the provision of a full integrity positioning service. The purpose of the current study is to assess the possibilities that a mass-market level multi-antenna device could offer in order to improve integrity by identifying faulty measurements (i.e. high error measurements). Using the real data collected with a GPSG this is because antenna phase differences contain information related to the direction of arrival (DoA) of the received signals, also known as angle of arrival (AoA). NLoS measurements do not usually arrive from the expected DoA, which for direct signals can be obtained from user attitude and satellite Line-of-Sight (LoS), so this turns phase differences into a potential indicator that can be used to detect NLoS. Besides, the paper demonstrates how, only using the antenna phase differences, the presence of a spoofer can be detected when the spoofing signals arrive from the same direction. This can be done without any external info, even without calibrating the difference between the antenna HW biases.