Stream Anaysis Using SAS
The modules in this repositry are simple examples of stream identification / analysis approaches using D Criterion methods to compare orbits against a reference orbut. All of these examples are implemented in either "Base SAS" (The SAS natural language) and as a workflow using the graphical SAS Studio development tool (the latter providing an example of a workflow).
The implementation of D Criterion comparisons include Southworth and Hawkins (DSH) and the Jopek hybrid (DH), whilst the more comlex examples also include implementations of the Drummond (DD).
We hope that others will be willing to contribute ideas, improvements (bug fixes) and analytical methods so that we can add to this suite and build a more complete set of resources for the meteor community.
Peter Campbell-Burns, Richard Kacerek UK Meteor Observation Network email@example.com
|Orbital_Similarity Single.sas||Simple DD / DH / DD Stream analysis (Base SAS)|
|Orbital_Similarity Best Fit.sas||Performs iterative stream analysis (Base SAS). It compares each orbit against a list of reference streams and assigns a shower according to the lowest D Criterion value. This module implements DH, DSH, and DD|
|Orbital_Similarity Multi.sas||Performs an iterative stream analysis (Base SAS). D values are calculated each reference orbit in turn and plotted (histogram and CDF). Only meteors where the solar longitude falls within the minimum and maximum solar longitude for the shower are plotted. This module implements DH, DSH, and DD|
|D_Criterion_EX4,sas||Workflow example: Iterative stream analysis (SAS Studio) against a list of streams. This module implements DH, DSH, and DD|
|J8.csv||Reference data: Orbital elements of known showers|
SAS (Statistical Analysis System) is a software suite supporting advanced analytics, multivariate analysis, business intelligence, data management and predictive analytics and competes with products such as SAP BusinessObjects, IBM Cognos, SPSS Modeler, Oracle Hyperion, and Microsoft BI. SAS recenty released it's "University Edition" which is available at no cost. SAS University Edition includes SAS Studio, Base SAS, SAS/STAT, SAS/IML, SAS/ACCESS and several time series forecasting procedures from SAS/ETS. It is the same analytics software used in business, government, and universities around the world.
Why use SAS?
- A mature and well supported productised across many indutries for Business Intelligence and Data Integration applications
- Highly adept at handling the type of data generated by the Sonotaco UFO Suite
- Fast / efficient
- SAS Studio "Workflow" approach
- It's free
- It's learning curve is less steep than "R" (A subjective view, but it's data types are far simpler)
- I use it every day in my day job
So why not? Having also implemented the same D Criterion methods in "R", SAS feels simpler and a lot more natural once the idiosyncracies of the language are understood. However, we have yet to explore SAS' graphical capabilities properly. Like "R", there is a of on-line support available including user forums.
Getting SAS University Edition
SAS runs on Windows, Linux or APPLE in a virtual environment. Check that your computer meets the minimum requirements.
- Drummond J. D. (1981). “A test of comet and meteorshower associations”
- Jopek T. J. (1993). “Remarks on the meteor orbitalsimilarity D-criterion”
- Southworth R. B. and Hawkins G. S. (1963). “Statistics of meteor streams”.
This work is shared under the Creative Common Non Commercial Sharealike License V4.0 (www.creativecommons.org/licebses/by-nc-sa/4.0/)