PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM RECORD_BYTES = 80 SPACECRAFT_NAME = GIOTTO TARGET_NAME = "HALLEY" OBJECT = TEXT PUBLICATION_DATE = 2006-11-06 NOTE = "AAREADME.TXT File for data set: GIOTTO C NMS 4 1P/HALLEY V1.0 " END_OBJECT = TEXT END NMS ARCHIVE FOR THE COMET ENCOUNTER PHASE 1. Introduction This archive contains derived data of the NMS instrument on GIOTTO. It also contains documentation which describes the NMS data, the calibration they have undergone and a note on the confidence level The NMS data archived in this data set are the best currently available NMS data. Supporting documentation and label files conform to the Planetary Data System (PDS) Standards, Version 3.6, Jet Propulsion Laboratory (JPL) document JPL D-7669, Part 2. Additional information about the NMS experiment can be found in documents on ESA's file servers and from the PDS Small bodies Node. 2. Volume format N/A 3. File formats The NMS data consists of tables containing densities of a given mass/charge vs Distance from the nucleus along the Giotto trajectory as well as ion tempera- ture and velocity as a function of distance. All data files are in pure ASCII and use a TABLE object with attached label. The RECORD_TYPE is fixed length with 80 bytes records. Structure pointers, which describe the table COLUMNs, are defined in the labels in order to keep it easy readable. All document files (except PDF format) contain 80-byte fixed-length records, with a carriage return character (ASCII 13) in the 79th byte and a line feed character (ASCII 10) in the 80th byte. This allows the files to be read by the MacOS, DOS, Unix, and VMS operating systems. All tabular files are described by attached PDS labels. There are a few exceptions from fixed-length records. One is the file PNG_DESCRIPTION.TXT which was added together with the browse products by Bjoern Grieger. It uses the stream record type with variable record length. For the files VOLDESC.CAT, LABINFO.TXT, and this file AAREADME.TXT itself, the RECORD_TYPE was changed to STREAM for PDS compliance, as the keyword FILE_RECORDS is missing. Tabular files are formatted so that they may be read directly into many database management systems on various computers. All fields are separated by commas, and character fields are enclosed in double quotation marks ("). Character fields are left justified, and numeric fields are right justified. The "start byte" and "bytes" values listed in the labels do not include the commas between fields or the quotation marks surrounding character fields. The records are of fixed length, and the last two bytes of each record contain the ASCII carriage return and line feed characters. This allows a table to be treated as a fixed length record file on computers that support this file type and as a normal text file on other computers. PDS labels are object-oriented. The object to which the label refers (e.g., IMAGE, TABLE, etc.) is denoted by a statement of the form: ^object = location in which the carat character (^, also called a pointer in this context) indicates that the object starts at the given location. In an attached label, the location is an integer representing the starting record number of the object (the first record in the file is record 1). In a detached label, the location denotes the name of the file containing the object, along with the starting record or byte number. For example: ^TABLE = "INDEX.TAB" indicates that the TABLE object points to the file INDEX.TAB . Pointers to data objects are always required to be located in the same directory as the label file, so the file INDEX.TAB in this example is located in the same directory as the detached label file. Other types of pointer statements can also be found in this dataset.To resolve the pointer statement, first look in the same directory as the file containing the pointer statement. If the pointer is still unresolved, look in the following top level directory: ^ STRUCTURE - LABEL directory ^ CATALOG - CATALOG directory ^DATA_SET_MAP_PROJECTION - CATALOG directory ^DESCRIPTION - DOCUMENT directory. Below is a list of the possible formats for the ^object keyword. ^object = n ^object = n (used for our TABLES) ^object = "filename.ext" (used for COLUMN definitions) ^object = ("filename.ext",n) ^object = ("filename.ext",n) where n is the starting record or byte number of the object, counting from the beginning of the file (record 1, byte 1) indicates that the number given is in units of bytes filename is the upper-case file name ext is the upper-case file extension 4. Dataset contents The files in this dataset are organized in one toplevel directory with several subdirectories. The following table shows the structure and content of these directories. In the table, directory names are enclosed in square brackets ([]), upper-case letters indicate an actual directory or file name, and lower-case letters indicate the general form of a set of directory or file names. FILE CONTENTS Top-level directory | |- AAREADME.TXT The file you are reading. | |- ERRATA.TXT Description of known anomalies and errors | present on this dataset. (if present) |- VOLDESC.CAT Volume catalog file | | |- [BROWSE] A directory containing NMS browse products | | | |- [NEUTRALS] Directories containing NMS neutral gas | | | browse products | | |- [N-UNPUB] Directory containing unpublished neutral data | | | browse products | | |- [N-PUB] Directory containing published neutral data | | browse products | |- [IONS] Directories containing NMS ION browse | | | products | | |- [I-UNPUB] Directory containing unpublished ion data | | | browse products | | |- [I-PUB] Directory containing published ion data | | browse product | |- [OTHERS] Directories containing other NMS browse | | products | |- [PLASMA] Directory containing velocity and temperature | | data browse products | |- [YIELD] Directory containing specific yield data | browse products | | |- [CATALOG] A directory containing information about the | | NMS dataset. | |- CATINFO.TXT Description of files in the CATALOG | | directory. | |- DATASET.CAT PDS dataset catalog object. A description | | of the dataset, parameters, processing, data | | coverage and quality. | |- *.CAT PDS catalog objects. Mission, spacecraft, | instrument, personnel, reference, and | software descriptions. | |- [DATA] A directory containing NMS data files. | | | |- [NEUTRALS] Directories containing NMS neutral gas data | | | files | | |- [N-UNPUB] Directory containing unpublished neutral data | | | | | |- [N-PUB] Directory containing published neutral data | | | |- [IONS] Directories containing NMS ION data files | | | | | |- [I-UNPUB] Directory containing unpublished ion data | | | | | |- [I-PUB] Directory containing published ion data | | | |- [OTHERS] Directories containing other NMS data files | | | |- [PLASMA] Directory containing velocity and temperature | | data | |- [YIELD] Directory containing specific yield data for | the NMS detector | | |- [DOCUMENT] A directory containing document files | | | |- DOCINFO.TXT Description of files in the DOCUMENT | directory. | | |- [INDEX] A directory containing index files relating | | to this volume. | |- INDXINFO.TXT Description of files in the INDEX directory. | | | |- [LABEL] A directory containing label and include | files from the attached labels |- LABINFO.TXT Description of files in the LABEL direcotory 6.Errata and Disclaimer A cumulative list of anomalies and errors is maintained in the file ERRATA.TXT at the root directory of this dataset. Although considerable care has gone into making this dataset, errors are both possible and likely. Users of the data are advised to exercise the same caution as they would when dealing with any other unknown data set. Reports of errors or difficulties would be appreciated. Please contact one of the persons listed herein. 7. Whom to Contact for Information For questions concerning this dataset, data products and documentation: University of Bern, Kathrin Altwegg, Physics Institute Division of Space Research and Planetary Sciences Sidlerstrasse 5 CH-3012 Bern Switzerland Phone: (+41 31) 631-4415 Fax: (+41 31) 631-4405 Email: altwegg@space.unibe.ch For questions concerning the generation of NMS products: University of Bern, Thierry Semon, Physics Institute Division of Space Research and Planetary Sciences Sidlerstrasse 5 CH-3012 Bern Switzerland Phone: (+41 31) 631-4425 Fax: (+41 31) 631-4405 Email: thierry.semon@phim.unibe.ch For questions concerning the generation of browse products: Aurora Technology B.V. for ESA - European Space Agency Bjoern Grieger ESAC Camino Bajo del Castillo s/n Urb. Villafranca del Castillo E-28692 Villanueva de la Canada Madrid Spain Phone: +34 91 81 31 107 Fax: +34 91 81 31 218 Email: bjoern.grieger@esa.int