Received signal quality as a function of satellite elevation using a Javad Eurocard receiver ('JPSEuro') and a range of AML GPS antennae. The Quality Figure scale is in dB and effectively proportional to received power in dB at 1575.42 MHz for these examples. The scatter is typical, the received signal from a satellite fluctuates by two units over several seconds and is also effected by the antenna's surroundings. Two examples are given in the key; the AD410 L1/L2 antenna uses dielectric patches in its antenna element, whilst the AD420 uses a crossed dipole. The black line shows the expected trend for a generic high performance GPS antenna in operation, with an approximately 15 dB variation in gain from 5 degrees to 90 degrees in elevation. [The orange diamonds were obtained with an antenna from another manufacturer].