Definition of Duplicate Observation
A proposed observation is considered a duplicate of another observation if all of the following conditions are met:
- Target field location
- For a single-field, the proposed position coincides within the half-power beam width of the
other observation. Moving objects (e.g., Solar System objects) will be identified by name. - For mosaic observations, more than 50% of the proposed pointings are within the half-power beam width area covered by the other observation.
- For evolving or variables sources, the duplication is not scientifically justified.
- For GBT monitoring programs, no two active programs can monitor the same proposed position that coincides within the half-power beam width of the other observation. Moving objects (e.g., Solar System objects) will be identified by name.
- Angular Resolution
- The proposed angular resolution differs by a factor of ≤ 2 from the other observation.
- Spectral Windows
- For the VLA and VLBA,
- Continuum: The requested sensitivity (rms) for the aggregate bandwidth is better by a factor of ≤ 2 from the other observation and the requested frequency is within a factor of 1.3.
- Spectral line: If the central frequency in any requested correlator window is encompassed by the other observation and the sensitivity per spectral channel, after smoothing to the same spectral resolution, is better by a factor of ≤ 2. Or, if the spectral resolution, as justified by the science case, is better by a factor of ≤ 2.
- For the GBT,
- Continuum: The requested sensitivity (rms) for the aggregate bandwidth is better by a factor of ≤ 2 from the other observation and the requested frequency is within a factor of 1.3.
- Spectral Lines: Within the largest beam size of two receivers with overlapping frequency ranges, any spectral line being the same while taking into account velocity/redshift.
Solar observations will not be checked for duplication.
