Index of /holdings/ihw-c-lspn-2-didr-halley-v1.0
Name Last modified Size Description
Parent Directory -
browse/ 16-May-2011 13:54 -
calib/ 18-May-2011 10:28 -
catalog/ 17-May-2011 10:57 -
CODE/ 16-May-2011 12:15 -
data/ 17-May-2011 11:09 -
document/ 18-May-2011 14:13 -
DOWNLOAD/ 23-May-2012 07:57 -
geometry/ 17-May-2011 10:20 -
index/ 23-May-2012 07:21 -
software/ 25-Jul-1990 07:17 -
aareadme.txt 17-May-2011 11:26 4.6K
dataset.html 03-Jun-2014 08:45 4.1K
voldesc.cat 17-May-2011 10:57 3.8K [PDS catalog file]
PDS_VERSION_ID = PDS3
RECORD_TYPE = "STREAM"
OBJECT = TEXT
PUBLICATION_DATE = 2011-05-16
NOTE = "AAREADME File for re-organized IHW data set"
END_OBJECT = TEXT
Re-organized International Halley Watch (IHW) Data Sets
The original IHW "LSPN disks" contained ground-based observations from
various observatories contributing to the Large-Scale Phenomena Net.
These data, originally consituting the CDROM volumes HAL_0001 to
HAL_0018, have been combined here in a single, integrated logical
volume, sorted by date.
The observational data are in a compressed format that is not supported
by PDS. These original files are under the COMPRESSED/ subdirectory
of the DATA/ directory. The browse data are sub-sampled, raster versions
of thecompressed images and are stored in a parallel directory structure
under BROWSE/. Browse files have names that correspond to their original
observational image file names. Calibration observations are also included
in the CALIB/ directory, and the summary index and errata information
provided on the final disk in the LSPN series, HAL_0018, has been
incorporated into the DOCUMENT/ subdirectory here.
In the HAL_0019-HAL_0023 "mixed disks", subsampled versions of the
LSPN observations and calibrations were included that, while apparently
identical to the browse images in terms of data content, had improved
labels with at least minimal metadata included (start time, LSPN number,
and target, for example). These have been included in the SUBSAMPLED/
subdirectory of the DATA/ directory.
Some description of the compression/decompression algorithm and source
code was included on the original disks, and is duplicated here. It is
unlikely the source code will compile on any modern system, but it may
at least provide an example of the algorithmas once used.
The data were also archived under a fairly early form of the PDS
Standards, and formatted to an equally early form of the FITS
standard, where appropriate, resulting in some particularly arcane
formats for the modern user - including PDS labels with deprecated
terminology and almost no metadata, a FITS headers which refer to an
extension type of 'COMPRESS' that was never formally adopted into the
standard and no longer exists even as a conforming extension.
The reorganization effort sought to separate the data files constituting
the unique data sets into a more contemporary, single-data-set-per-volume
format for ease of access and distribution.
The data files and most supporting files are presented here in their
original format, problematic though that might be. Users interested in
analyzing the data would probably do well to inquire of the PDS or the
Small Bodies Node for version 2.0 of the observational data set.
- A.C.Raugh, 2011-05-16