Total power in decibel-kelvin scale (calculated as 10 log₁₀(T_sys)) of the AAVS1 station beam at zenith at 159.375 MHz, as a function of local time (top image). The black curve is the data points from the AAVS1 real-time station beam. The solid blue curve is the model prediction using the GSM and the dashed red curve is the prediction using the HASLAM map scaled to our observing frequencies using a spectral index of −2.5. Both predictions incorporate a model of the AAVS1 station beam pointed at zenith. The lower plot shows the difference between the data and simulated curve using GSM sky model (maximum difference ≈15%) and scaled HASLAM map (maximum difference ≈20%). The vertical spikes are due to RFI or lost packets, which used to occasionally happen when there were other processes running on the AAVS1 server during the data acquisition.