  Being able to accurately predict the arrival of coronal mass ejections (CMEs)
at Earth has been a long-standing problem in space weather research and
operations. In this study, we use the ELlipse Evolution model based on
Heliospheric Images (ELEvoHI) to predict the arrival time and speed of 10 CME
events that were observed by HI on the STEREO-A spacecraft between 2010 and
2020. Additionally, we introduce a Python tool for downloading and preparing
STEREO-HI data, as well as tracking CMEs. In contrast to most previous studies,
we use not only science data, which has a relatively high spatial and temporal
resolution, but also low-quality beacon data, which is - in contrast to science
data - provided in real-time by the STEREO-A spacecraft. We do not use data
from the STEREO-B spacecraft. We get a mean absolute error of 8.81 $\pm$ 3.18 h
/ 59 $\pm$ 31 kms$^{-1}$ for arrival time/speed predictions using science data
and 11.36 $\pm$ 8.69 h / 106 $\pm$ 61 kms$^{-1}$ for beacon data. We find that
using science data generally leads to more accurate predictions, but using
beacon data with the ELEvoHI model is certainly a viable choice in the absence
of higher resolution real-time data. We propose that these differences could be
minimized if not eliminated altogether if higher quality real-time data was
available, either by enhancing the quality of the already available data or
coming from a new mission carrying a HI instrument on-board.
