Old manual but the principals apply.
The following application is written in Powerhouse.
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The ARGOS application allows users to manipulate ARGOS PTT data and produce maps and listings.
To start the application, typing ARGOS once logged onto Marvin and the first screen looks similar to this. There may be slight differences as the application evolves ahead of this manual.
To activate any of the options, just type the number on the left in the action box.
Screen 10 Programs and batch reporting allows the user to cluster multiple PTT profiles together as one logical unit that can be reported via one action. The following example displays the program 973 and lines 4 to 13 display several PTTs and some of the data from the profile.
Investigator and details are for storing the chief invstigator of the program and details of its purpose. Please enter these if missing so the maintainer of the application can sort out any problems with particular ptts/programs.
Batch name is a name that the user can assign to this program and is used by the VAX to name the batch job that gets created. The options at the bottom allow the user to control this job.
Screen 11 allows the user to create a profile of a PTT that can be used repeatedly to plot maps and/or produce a list of positions and distances from specified reference points.
A profile is a set of parameters that control the extraction of data from the Argos data sets and then the mapping of that subset of data.
Each profile has a unique computer generated number starting from 1. By using this to identify the profile, instead of the PTT number, you can change the PTT number without casuing problems with profiles linked to multi-profile plots. Screen 11 has multiple keys. It will ask for a record via
The above example requires data about PTT number 1398 from 13-Nov-1994 to 30-Nov-1994 excluding data with quality below 1 and using Edmondson Point in the Ross Sea as the reference point. A map is constructed using the set map limits and not the bounds of the data. When first plotting some data, it is useful just to let the data control the map plot bounds so that all data is visible. After selecting some suitable map limits then set the flag Autoscale map to N.
Once you have a profile then use the following commands
Unfortunately it cannot be directed to the Mac file server so they stay in your login area on the vax. Do the following
Some parameters and how they control the data.
The method used is
The following graph show the original RMS speeds for 78 data points (in black). After filtering for speeds above 5 km/hr, the red line is the result. Note that removing one 'bad' point can significantly lower the RMS velocity for surrounding points. In this case only 7 points were filtered out
This method has the advantage of excluding bad points no matter what class.
Class 0 or worse have no guaranteed position nor error radius. Class 0 hits have been known to appear on the other side of the world. Giving it an error radius is meaningless.
At the top of the listing is the date range, profile name and comments from the profile, the miminum quality of fixes used and the start reference point.
It contains the following columns
The final column (marked L for light) is a flag to indicate how dark it is
This screen allows the user to associate several profiles together and then plot them on a common map.
Finally once a profile is created, do either of the following
Some hints - use a low resolution map such as tas_to_msn until you get the desired result and then use the high resolution map aat_coast.geo for a final output. This later map takes a while to read and plot.
Unfortunately it cannot be directed to the Mac file server without corruption so they stay in your login area on the vax. Do the following
The following example plot of 3 profiles shows the two birds are near each other whilst the 3rd bird is typically more than 60 km from them. The index on the right hand side shows which PTTs are paired per plot.
Screen 12 is a maintenance table of reference points and locations that can be used to calculate distance and bearings from as the PTT transmitter wanders about. A three letter code is used to identify the location. Use a sensible code that is easy to remember. Note some locations are ships as this table is used by many other applications so please dont muck it up indescriminately.
If relevant, enter positions as decimal degrees (negative for southern latitudes or western longitudes) and decimal minutes.
Map name is the actual VMS filename. The above examples live in the directory pointed to by the logical map:. These maps have a specfic data format. Contact the author for more details.
Filenames ending with GEO are recent and better resolution maps. All new map files will eventually replace the older *.DAT files.
Both these options create a log file of the session with the Argos computers, and if the appropriate commands were used, the log file will contain the PTT data amongst other text. See the last section for details of some Argos commands.
Statistics from loading recent PTT data Records read 1191 New records added 833 Old records updated 357 For file: SCISUP:[ARGOS.SCRATCH]ALL_DISPOSE_DAILY.DAT;2 Program PTT Passes Dates Notes 366 1171 41 1996 01 10 to 1996 01 11 1172 46 1996 01 10 to 1996 01 11 1173 37 1996 01 10 to 1996 01 11 973 1398 21 1996 01 10 to 1996 01 11 21055 30 1996 01 10 to 1996 01 11 23358 19 1996 01 10 to 1996 01 11 23360 19 1996 01 10 to 1996 01 11 25985 21 1996 01 10 to 1996 01 11 25986 6 1996 01 10 to 1996 01 10 25987 33 1996 01 10 to 1996 01 11 25989 34 1996 01 10 to 1996 01 11 27169 5 1996 01 11 to 1996 01 11 No calibration file for PTT 1155 4471 39 1996 01 10 to 1996 01 11 4473 37 1996 01 10 to 1996 01 11At the top is the total number of records contained in the download, the number of records that were updated and the number of new ones. Since the load occurs every day and we get two days data, the number of updated records is about the same as the number of new records. A PTT will create at most 28 messages per day, ie a message per pass.
Further down is the PTT and its program along with the number of messages processed. If a calibration file is missing, it is noted in the last column. This file is important as it contains the dates when the PTT is valid along with conversion factors for converting sensor data to real units. For tracking purposes, the conversion factors are not important.
Note that by the time you query the database, the data is between 4 and 24 hours old. If you wish to get the most recent positions (for example retrieving an incoming PTT) then you will need to login directly to the Argos computers.
The Argos computers retain only the last 4 days data online. After that it is purged. About two to three weeks after the end of a month, the Division receives a tape containing the complete records from the last month. It is a superset of the daily downloads. All data in the database is replaced with this set of data. You know when a new set of data has been added when you receive a mesage like...
Date: Tue, 16 Apr 1996 14:17:07 +1000 (EST) From: "John Morrissy, Antarctic Div."This signifies that new Class Zero (CZ) and Dispose (DS) data files for Feburary 1996 have been processed. It has been sent to the email list ARGOS_USERS.
To: ARGOS_USERS@antdiv.gov.au CC: JOHN_MOR@antdiv.gov.au Subject: New monthly Argos tape These files from the new monthly Argos tape are now in ARGOS_DATA DS_1996_02.DAT CZ_1996_02.DAT
Note that a repeated analysis of the last months data may give rise to a different output. After three months, Argos remove all data and expect the host institute to retain the data. The current online database at the Division goes back to 1991 with tapes going back to 198?. There are notes on how the process for downloading ARGOS data.