Visit the tips page to look for answers to some usage questions.
Read the paragraph on backgrounds in Herschel maps if you ever wondered about them.
If you wonder about the shape of some point sources in PACS maps:
On the PACS Calibration Web, you will find a very useful document describing the structure and possible
distortions of the point spread functions (in particular the elongation and undershooting at high scan speed).
Likewise, on the SPIRE Calibration Web, you will find up-to-date documentation about the average beams.
| documentation and reference
|| download and installation
Scanamorphos is an IDL software to build maps from scan observations made with bolometer arrays, in particular with the PACS and SPIRE photometers onboard the Herschel space telescope (wavelength range of operation: 70 to 500 µm). The prototype software has been developed on SPIRE simulated data and on real data from P-Artemis, an instrument of the same design as one of the PACS subarrays, but operating on the ground (mounted on APEX). After the launch and performance verification of Herschel, it has been extensively tested on both SPIRE and PACS flight data.
Scanamorphos is chiefly designed to remove the low-frequency noise, both thermal and non-thermal, causing additive brightness drifts. To this end, it makes use of the redundancy built in the observations (each portion of the sky with nominal coverage is sampled by multiple bolometers at multiple times) to derive the brightness drifts directly from the data themselves. This means that Scanamorphos does not depend on any noise model, and is thus immune to mismatches between models and reality, that may occur because the noise is not perfectly calibrated, or does not satisfy the model assumptions, or varies in time, or is altered by the pre-processing (from level 0 to level 1 in the Herschel jargon). Furthermore, the algorithm is adaptable to other bolometer arrays, by modifying the few instrument-specific parameters.
Scanamorphos is flux-conserving and restores sources on all spatial scales, ranging from point sources to extended structures with scales just below the map size. (Of course, there is no hope of faithfully restoring brightness gradients on scales larger than the map; to handle these, strong assumptions have to be made.)
Here are the main functionalities:
The processing is fully automated, but ample visualization of intermediate results at various steps is enabled.
If you use Scanamorphos to map your SPIRE data, you might need point response functions (PRF) also mapped with Scanamorphos. PRF built in March 2010 from Uranus observations are available from this page. They will be updated when I find the time.
* portmanteau word composed of "scan" and "anamorphosis"
anamorphosis: reversible transformation of an image by a mathematical or optical operator
(from the Greek , implying the idea of a transposition or return; and : shape)
documentation and reference:
download and installation:
inquiries, bug reports, suggestions for improvements or new functionalities: