Which two reasons could explain why a raster image would not align with reference data?

When considering why a raster image might not align with reference data, one pivotal reason is that the aerial image was not orthorectified. Orthorectification is a process that corrects the distortions in aerial images caused by terrain relief and camera tilt. Without this correction, the image retains these inaccuracies and will likely not align correctly with reference data that is usually rectified and precise. This misalignment is especially evident when comparing with highly accurate spatial datasets, leading to potentially significant errors in spatial analysis or decision-making.

Additionally, another factor contributing to misalignment can be that the data is in a different projection than the reference data. Projections transform three-dimensional Earth data into two-dimensional maps, and if the raster image uses a different coordinate system or projection than the reference data, it can lead to noticeable differences in alignment. Hence, ensuring consistent spatial referencing across datasets is crucial for accurate mapping and analysis.

While the extent not being defined and the spatial reference being undefined can cause issues with data usability, they are not as specifically linked to physical misalignment with reference data as the other two reasons described.