The SCUBA-2 reduction pipeline is being reviewed on December 10th
(see http://scuba2.jach.hawaii.edu/deltapdr.html for documents).
We are currently expecting to be writing new applications in C, with DRAMA
as the messaging interface and NDF as the native file format. Obvious
questions from the review panel are then:
- Why DRAMA?
+ ADAM is difficult to justify for new code
+ SOAP and C do not seem to be a common combination
+ We use DRAMA all over the place for low level control of the
telescope and instruments.
- Why NDF?
+ We are using Starlink applications
+ I much prefer it to FITS
+ I hope it can read large files
- Why C, when everyone (even the SPIRE pipeline from which we are
using FTS algorithms) is moving to Java?
+ It is hard to justify Java given our data rates
(500 GB/night)
To minimize issues such as this we are proposing to develop an abstraction
layer that will remove the algorithm writer from the DRAMA/NDF issues. The
obvious model for the NDF part is HDX/NDX (since that can provide an
identical view for both FITS and NDF) and I've recommended that the FTS
team adopt it for their pipeline integration. Unfortunately HDX/NDX is
only in Java which makes it hard to use from C.
+ How much effort would it be to write a C version?
+ Is there any detailed documentation on HDX (including an XML schema)?
--
Tim Jenness
JAC software
http://www.jach.hawaii.edu/~timj
