



Bird Dog User's Guide

Version 2.0 


 by The Space Technology Education Program
at The Environmental Research Institute of Michigan, Ann Arbor, MI

Supported by NASA Educational Affairs Division Grant NGT-80006

 Copyright 1989 by The Environmental Research Institute of Michigan.  
All rights reserved.




IF YOU NEED HELP...

If you encounter difficulties in installing or running Bird-Dog and this manual cannot help you solve them, please write or phone Mr. Peter Tchoryk, Environmental Research Institute of Michigan, P.O. Box 134001, Ann Arbor, MI 48113-4001.  (313) 994 - 1200.



TABLE OF CONTENTS


	PART ONE:  INTRODUCTION AND INSTALLATION

SECTION I  OVERVIEW

   What is Bird-Dog?  
   System Requirements and other Specifications  
   Definitions & Terminology 
   If You Need Help  

SECTION II  INSTALLING BIRD-DOG
   Installation on a Floppy System 
   Installation on a Hard Drive System
   Installation on a RAM disk System

	PART TWO:  BECOMING FAMILIAR WITH BIRD-DOG

SECTION I  Running Bird-Dog
   Startup Procedures
   Overview
   Summary of Bird-Dog Commands

SECTION II  Updating Bird-Dog Data Files
   Updating Ground Station Parameters
   Updating Satellite Parameters.
   Modified NASA Prediction Bulletin Format


SECTION III  UPDATING BIRD-DOG DATA FILES
   Selecting a ground station
   Updating satellite parameters



PART ONE:  INTRODUCTION AND INSTALLATION

SECTION I  OVERVIEW

What is Bird-Dog?

	Bird Dog is a satellite tracking program written by Thomas C. Leadholm, formerly of the Environmental Research Institute of Michigan (ERIM).  It is intended for use by participants of the Space Technology Education Program (STEP) in both the teaching of basic orbital mechanics of weather satellites and to supplement a Direct Readout Station.  Bird-Dog is capable of predicting satellite passes and displaying satellite acquisition windows for your location.  It shows the position of the satellite being monitored on either a flat world map or a spherical 3- dimensional plot of the earth.  These maps show coastlines, islands, rivers, state and country boundaries, and assist in discerning land features during real time acquisition of weather images.


System Requirements and other Specifications

Minimum Requirements:	IBM compatible with 256K of memory and an EGA graphics card.

Recommended configuration:	10Mhz+ IBM compatible with VGA graphics, a math co-processor, and a 23 ms (or less) hard disk.

While Bird-Dog will run on a standard PC, its performance will be enhanced if run on the configuration recommended above.  For example, the displays of the spherical earth takes approximately 5 minutes to draw on a generic IBM PC with a 40 ms hard disk and no math co-processor.  An IBM AT compatible, on the other hand, with a math co-processor and 23 ms hard disk, will take only 20 seconds to draw the same screen.

Definitions & Terminology


The following is a partial list of acronyms used in this manual, and are terms that any one interested in satellite readout stations should be familiar with.

AVHRR	Advanced Very High Resolution Radiometer 
EBBS	Electronic Bulletin Board Service
EDS 	Electronic Data Systems
FOV	Field of View
GAC 	Global Area Coverage
GMT	Greenwich Mean Time (Zulu)
IR	Infrared imagery
LAC	Local Area Coverage (1 kilometer data)
NESDIS	National Environmental Satellite, Data, and Information         Service
NOAA	National Oceanic and Atmospheric Administration
RBBS	The Dallas Remote Imaging Bulletin Board Service
VIS	Visible imagery

SECTION II.  INSTALLING BIRD-DOG

Everything needed to run Bird-Dog comes on one diskette. This floppy disk should be backed up before proceeding with the installation.

Bird-Dog may be run directly from either a floppy drive (although this is not recommended), hard drive, or RAM disk.

Distribution files:

	BIRD-DOG.EXE	The satellite tracking program
	NEST.DAT	Ground station specification
	BIRD.DAT	Satellite ephemeris
	BIRDLST. DAT	A sample list of satellites to track
	KEP2BD.EXE	Creates BIRD.DAT from KEP.LOG
	KEP.LOG	A sample Bulletin Board file containing ephemeris for approx. 80 satellites.
Installation on a Floppy System

To run Bird-Dog from a floppy drive, simply place a backup of the distribution disk in one of the available drives after booting up, and enter "BIRD-DOG" at the DOS prompt.


Installation on a Hard Drive System

To install Bird-Dog on a hard drive, first create a directory from which the program will be run (e.g., "MD c:\Bird-Dog").  Then copy all of the files from the distribution disk to this directory.  


Installation on a RAM Disk 

If your system has a RAM disk with 360K bytes or more, you can greatly improve the performance of Bird-Dog by running it from the RAM disk.  To run Bird-Dog from a RAM disk, first create the Bird-Dog directory as above and then copy the distribution files to it.  You may find it convenient to set up a batch file to do this (refer to your DOS manual).  The time it takes to do this will be quickly recouped from the performance increase in Bird- Dog.



PART TWO:  BECOMING FAMILIAR WITH BIRD-DOG


SECTION I.  Running Bird-Dog

Startup Procedures

To run Bird-Dog, you must be logged onto the directory with Bird-Dog distribution files (Bird-Dog expects to find its files in the logged directory).  Throughout this manual, it will be assumed that Bird-Dog has been loaded onto a hard disk.

Bird-Dog is started by entering "Bird-Dog" at the DOS prompt.  The Space Technology Education Program (STEP) logo will then be displayed.  


The Tracking Screen

After Bird-Dog is started, a flat-projection map of the world will be drawn and the current position of available satellites will be marked.  The available satellites are determined by the contents of a file called BIRD.DAT.  Refer to the Updating Ephemeris Data section for more information about this file.  A menu, listing available commands is provided at the top of the Screen.

The file BIRD.DAT contains ephemeris data (orbital parameters) for each satellite to be tracked.  Bird-Dog is capable of tracking 16 different satellites.  The ephemeris data for some of the more popular weather satellites (several U.S. and Soviet birds) is provided on the distribution disk.  This ephemeris data is critical to the accuracy of Bird-Dog and should be updated at least every month.  It is not uncommon for orbits to vary five or six minutes every month.  Since the acquisition window of polar orbitors is so short, it is essential that Bird-Dog be as accurate as possible.  Instructions on how to update the ephemeris data is provided later in this chapter.

It should be noted here that since all orbital predictions are based on precise assumptions of time, it is critical that your computer's clock be accurate.  It is worthwhile making an effort to set the time in your computer to an "official" reading (e.g. Time service offered by your local telephone company) at least once a week.

The position of each satellite is recomputed by Bird-Dog every second, and is marked on the screen with a circle. These circles are color coded according to the current track mode of the satellite.  For example, if a satellite is traversing North to South, or in a Descending Node, the circle marking the satellites position is colored RED, while satellites traversing South to North, or Ascending, are colored YELLOW.  This visual cue makes the track of the satellites  readily apparent.

Each circle also has a number within it which corresponds to a list of satellites on the right side of the screen.  The current position of a selected satellite is displayed at the bottom of the screen and refreshed every second.  This information includes the latitude and longitude, azimuth and elevation, range, altitude, orbit number of the satellite, local station time and GMT.  

As each satellite tracks across the map, a colored line marks its passage.  Each satellite has a unique color assigned to it and it is thus possible to follow a specific trail for many orbits.  You can imagine how cluttered a screen would become after tracking sixteen satellites for an extended period of time.

Assuming your system clock and ephemeris data are up to date, the satellite markers depict very precise locations.  If you wish to determine where the satellite will be at some time in the future (for example, to determine when it will pass into view), use the Predict Orbit option F4.  Bird-Dog does this by incrementing the local time clock two minutes every second,  calculating the new position of the satellite and marking its position on the screen.  You may pause the screen by pressing the Space Bar, or end the predict mode by pressing the escape key.

If you wish, Bird-Dog will also show the position of a selected satellite on a three dimensional plot of the earth.  Highlight the satellite you wish to monitor and then press F3.  Bird-Dog will then draw a view of the earth from the vantage point of the satellite you selected, marking the position on the ground above which the satellite is currently located.  This map will be updated continuously until the ESC key is hit. If a Predict Orbit had been drawn prior to pressing F3, it will also be displayed.

Bird-Dog also has the ability to zoom in on a selected satellite by pressing F2.  A higher level of resolution in the data base will be accessed and window approximating the Field of View of the satellite will be used.  In this mode, more detailed topographic features, such as islands, rivers, and lakes are drawn, all of which aid in the identification of features that a satellite is currently scanning.  If you have the luxury of owning two PC's on your ground station, it is often helpful to have Bird-Dog, and the satellite capture software running side-by-side.  To exit from the view mode, press the escape key.

Summary of Bird-Dog Keyboard commands:


F1  [Function key 1]
   Pressing F1 displays a list of commands and a short description of each.

F2  [Function key 2]
   Pressing F2 instructs Bird-Dog to Zoom-In on the selected satellite.  A window will be drawn which depicts the approximate field of view of the satellite.  State and country boundaries will be drawn as well as rivers and lakes in this mode.  Tracking a satellite in this mode while receiving imagery has been found to be quite useful in identifying land features.

SF2  [Shift Function Key 2]
   Pressing SF2 instructs Bird-Dog to refresh, or redraw, the tracking screen.  All tracking lines will be erased and the current position of satellites remarked.
           
F3  [Function key 3]
   Pressing F3 draws a perspective view of the earth as it would appear from a selected view.  This function marks the current position of the satellite with a circle and the sequence number in the BIRD.DAT file.  Bird-Dog will also draw the last Predict Orbit, if one currently exists (see function key 4).
           
F4  [Function key 4]
   Pressing F4 instructs Bird-Dog to predict the orbit of a selected satellite.  To use this option, first select the desired satellite using F5, and then press F4.  A light green line will be drawn on the map, marking the passage of the satellite.  As it is doing this, orbital information will be updated on the bottom of the screen.  If you wish to pause the satellite, press the SPACE BAR.  This will allow you time to jot down time, coordinates, etc.  To resume the predict orbit, simply press the SPACE BAR a second time.

As the satellite approaches your ground station, a box, or window will be drawn that represents the first and last scan line that you can expect to receive during that pass.  Bird-Dog will continue to predict the orbit of the satellite in this fashion until you press the escape key, or until 1500 increments (2 minutes each) have been plotted.  Bird-Dog will automatically place you back in the view mode in the event of the later.

After the escape key is pressed, Bird-Dog will display a window which contains information about the acquisition windows that have been drawn.  The first line in each group depicts the time and position of the satellite when it first enters range of your ground station, and the last line depicts the position of the satellite just prior to leaving range of your ground station.  If the file is larger than the size of the window displayed, the contents of the file can be scrolled up and down using the arrow keys as well as the PAGE UP and PAGE DOWN keys.  If you wish to print the contents of the window, press F6. 

SF4 [Shift Function Key 4]
  The SF4 function is similar to the F4 function in that information regarding orbital passes is presented to the user.  SF4 differs, however, in that the predicted orbital paths are not drawn on the map.  The windows, or acquisition boundaries, are instead, displayed along with AOS (acquisition of signal) times.  This is a much faster means to ascertain AOS times and a longer look into the future is therefore possible.  As with the F4 function, the acquisition window data are saved to disk under the name of the satellite being monitored (with an extension ".DAT").

CNTRL F4 [Control F4 key]
Pressing Control-F4 puts Bird-Dog in a Time Lapse mode.  This option allows you to speed up time (forward or backwards) which is useful in determining which satellite is the next to come into range of your ground station.  By speeding up time and focusing attention on your ground station, it is a simple matter to determine the sequence of approaching birds.  This option is also useful in studying the orbital characteristics of various satellites.  For example, it is interested to watch the erratic orbit of GOES-5 in relation to the other geostationary satellites GOES 6& 7.  GOES-5, out of fuel and drifting out of control, is anything but stationary!

Arrow Keys [Up & Down]
The arrow keys are used to select one of a given list of satellites from t he Satellite box on the right side of the screen.  The satellite selected will be colored red in the list, and its marker on the map will be filled with Cyan.  

F6 [Function Key 6]
     The F6 function allows the user to dump the contents of the screen to an EPSON FX compatible printer.  The EPSON FX printer is considered to be the lowest common denominator in printer emulations and was thus selected as the first printer to be supported by Bird-Dog.  With future releases of Bird-Dog, other printers will undoubtedly be supported.  

F10 [Function Key 10]
   The F10 function instructs Bird-Dog to display the next line of menu items.

ESC [Escape Key]
    Pressing the Escape key has the effect of stepping backwards through a chain of options, or to exit from a specific mode.  For example, pressing the escape key while in the ZOOM mode has the effect of exiting that option and returning to the TRACK mode.  Pressing ESC in the TRACK mode, the opening screen, exits you from Bird-Dog.

SECTION II.  UPDATING BIRD-DOG DATA FILES  


Updating Ground Station Parameters

	In order for Bird-Dog to accurately compute acquisition windows, it must have specific information about your ground station (the location the readout station). Specifically, Bird- Dog needs the Latitude, Longitude and Elevation of your site.  The easiest way to obtain this information is from an atlas.  Accuracy is important, but not critical, and you may approximate your location to the nearest whole number.  

	Once the location and elevation of your site is known, the next step is to modify the NEST.DAT file provided with the Bird- Dog distribution floppy.  Any standard text editor or word processor may be used for this purpose.  Bird-Dog will access this file the next time it is started.  The following is an example of the NEST.DAT file:
________________________________________________________________
Ann Arbor, MI	<---  Station Location  (15 characters)
42.25	<---  Station Latitude  (degrees north)
-83.75	<---  Station Longitude (degrees west)
300 	<---  Station Altitude  (meters)
________________________________________________________________


Other TZ Variables

EDT5EDT	(Eastern Daylight Savings Time)
CST5CST	(Central Standard Time)
CDT6CDT	(Central Daylight Savings Time)
MST6MST	(Mountain Standard Time)
MDT7MDT	(Mountain Daylight Savings Time)
PST7PST	(Pacific Standard Time)
PDT8PDT	(Pacific Daylight Savings Time)
GMT1GMT	(Use if PC Clock = GMT)


Updating Satellite Parameters

A satellite tracking program, Bird-Dog included, is only as accurate as its ephemeris data.  As mentioned earlier, it is imperative to update orbital parameters whenever possible, and at least once a month.  Satellites, on the average,  will deviate from projected orbits based on ephemeris data at a rate of about 5 minutes per month.  Since the typical acquisition time of a satellite is approximately 14 minutes, it becomes obvious that using three month old ephemeris data may cause a complete miss of a transmission!

So what is ephemeris data, how does one acquire it, and how is it used by Bird-Dog?  
   
Ephemeris data, or Keplerian elements, are pieces of information that together describe the orbital characteristics of a satellite.  A detailed description of the mathematics involved in calculating an orbit are beyond the scope of this manual.  But it is important to learn how and where to capture this information, and in turn create a file that Bird-Dog can process.

There are several sources of Ephemeris data, all of which originate from information provided on the NOAA Electronic Bulletin Board (EBBS).  This is a public access service, and in many cases, a local telephone number is provided via EDS.  To find your local number, contact Dorris Smith, of EDS, at 1 (800) 433 - 8016, and request access to the NOAA EBBS.

Another source of Ephemeris Data is through the Dallas Remote Imaging Bulletin Board Service (RBBS).  This BBS has a wealth of information regarding all aspects of the direct readout program.  Their number is (214) 394 - 7438.  Their ephemeris data is usually under Bulletin #5, and is updated weekly.  

The most current orbital elements from the NASA Prediction Bulletins are carried on the Celestial RCP/M.  (513) 427-0674.  These are updated several times weekly.

A sample of Ephemeris Data, common to both organizations mentioned above, follows.  Only those satellites, which are of interest in this discussion are listed.



SAMPLE TRANSMISSION FROM DATALINK RBBS SYSTEM



==================  DATALINK BULLETIN MENU  ==================

         1 - About the DATALINK RBBS System
 * R     2 - ALL USERS should read this bulletin if you want
   E         access to this Bulletin Board!
 * A     3 - Reasons DATALINK RBBS is requesting membership 
             donations
   D
         4 - RBBS User's Guide

 ||||    5 - LATEST SATELLITE KEPLERIAN ELEMENTS-60 SATELLITES
         6 - Documentation on NASA Keplerian Elements-How to Use
 ||||    7 - AMSAT BULLETINS AND WEEKLY NEWS -- Orbital Elements
         8 - Soviet Weather Satellite Summary
         9 - NOAA Orbital Prediction PostCard Summary
        10 -" LISTENING IN" -- 60 MINUTES TRANSCRIPT OF KETTERING               GROUP
 ||||   11- Soviet Military Satellite Frequency Listing-- Larry             VanHorn
        12  =========== The W5YI Weekly Ham Newsletter ==========
        13  NOAA SATELLITE BULLETINS-NOTICES OF INTEREST
        14  NOAA SATELLITE BULLETINS-  UPDATES   (Updated 3/89)
        15  WEATHER SATELLITES----USER BIBLIOGRAPHY
        16  Dallas Remote Imaging Group (DRIG) - Mission Profile
******  17  How to build a Weather Satellite Groundstation-A             Primer ****
        18  NASA == 1988 == THE YEAR IN REVIEW
        19  Amateur Satellite Frequency Guide == Downlink             Frequencies
        20  Wrasse 666 digital Scan Converter == How to Purchase
        21  NOAA Weather Satellite APT Notes (Updated 11/21/87)
        22  Soviet Rocket Program --  A Historical Perspective
        23  GOES VAS Imaging System for IBM PC -- John DuBois             W1HDX
        24  TBUS Orbital Predictions -- R.I.G.(Bob Leggett)U.K.
        25  Soviet Space Activities Updates
        26  NASA News Wire Updates
        27  Texas Packet Radio Society (TPRS) Conference Notes
        28  Dallas Remote Imaging Group Image Files Listing
        29  LNA for WEFAX-VAS-HRPT-GPS -- John Dubois & Greg             Ehrler
        30  GOES Navigational Summary Update  (3/89)
        31  GOES WEFAX Information Note 89-W1 (3/89)
        32  GOES I-M CONFERENCE SUMMARY
        33  Ralph Taggart's New  APT Scan Converter and Book -             Update
        34  Dartcom 137-138 Synthesized Receiver Packaging- John             DuBois

Read what bulletin(s), L)ist, N)ew ([ENTER] = none)? 5

  Courtesy Dallas Remote Imaging Group
    Datalink RBBS ============> 214-394-7438

    Dedicated to satellite tracking, decoding of NOAA/Soviet
    meteorological satellite telemetry, and Digital Image
    Processing of satellite pictures.

    Jeff Wallach,      N5ITU, Chairman

    John Williams,            Co-Chairman
    John DuBois,       W1HDX, VAS/HRPT Design Engineer
    T S  Kelso,               Air Force/NASA liason
    Ed O'Grady                Soviet Space Program Analyst
    Jim Blocker,       KF5IW, Director Software Development
    Jose Sancho       WB5YFU, Director of Engineering

  All aspects of Amateur Radio covered on Datalink RBBS

============================================================


 ||||    5 - LATEST SATELLITE KEPLERIAN ELEMENTS-60 SATELLITES



- Current NASA Prediction Bulletins #544 -
More [Y]es,N)o,C)ontinuous,A)bort? Y                                    

The most current orbital elements from the NASA Prediction Bulletins are carried on the Celestial RCP/M, (513) 427-0674, and are updated several times weekly.  Documentation and software are also available on this system.  As a service to the amateur satellite community, the most current of these elements are uploaded weekly to the DataLink RBBS.  This week's elements are provided below.  The Celestial RCP/M may be accessed 24 hours/day at 300, 1200, or 2400 baud using 8 data bits, 1 stop bit, no parity.

                                      - TS Kelso
                                   SYSOP, Celestial RCP/M

[* NOTE :  THIS FILE HAS BEEN EDITTED TO INCLUDE ONLY COMMONLY *]
[*         RECEIVED APT WEATHER SATELLITES                     *]
NOAA 9
1 15427U          89196.47764042 0.00000488           28734-3 0  4043
2 15427  99.1448 183.9754 0014425 233.1046 126.8803 14.12086380236448

NOAA 10
1 16969U          89200.21509624 0.00000598           28162-3 0  2513
2 16969  98.6366 230.0955 0013415 153.2927 206.8943 14.23090983148495

Meteor 2-16
1 18312U          89197.05155044 0.00000219           18868-3 0  2913
2 18312  82.5532 196.6614 0012858 109.1610 251.0911 13.83492947 96506

Meteor 2-17
1 18820U          89197.08879468 0.00000215           18415-3 0  1310
2 18820  82.5437 257.5868 0016069 184.3558 175.7471 13.84183932 73685

Meteor 3-2
1 19336U          89198.88838834 0.00000391           10000-2 0  2175
2 19336  82.5439 153.9460 0018931  69.3292 290.9789 13.16855311 46958

NOAA 11
1 19531U          89199.89876582 0.00000494           29490-3 0  1061
2 19531  98.9414 143.7651 0012043 138.5761 221.6325 14.11072946 41948

Meteor 2-18
1 19851U          89195.09296800 0.00000116           10000-3 0   554
2 19851  82.5222 137.8092 0013064 231.1896 128.8588 13.83817828 18807


The procedure for capturing Ephemeris Data makes two assumptions of the user: 
 1) That the telephone number for either the NOAA Bulletin Board or the Dallas Remote Imaging Bulletin Board is known, and  2) that there is access to a personal computer, modem and a communications package such as Procomm (capable of saving files to disk).
  
The procedure for capturing Ephemeris Data may be summarized as follows:

1.   Start by backing up the current BIRD.DAT file you are currently using.  The simplest way to do this is to rename it to OLDBIRD.DAT.  

2.  Dial into either bulletin board listed above and step 
through the appropriate menus that will display the ephemeris data.

3.  Open a log file on your PC.  This procedure varies from one communications package to another, but most of the major packages have this capability.  Read the file, which will save the information on your PC.  After the file has been copied, turn off your log file.

4.   Exit the bulletin board and run the program KEP2BD.  This program reads the file BIRD_LST.DAT, which contains a list of satellites you wish to track, and then reads through a LOG file that has been downloaded form one of the bulletin boards mentioned above containing ephemeris data.  When a match is found between the satellite list and the log file, the satellite's Keplerian data is extracted and stored in the file BIRD.DAT.  A sample BIRD_LST.DAT file follows:

NOAA 9	The satellite name as found in log file
NOASS-9	The name as it will appera in Bird-Dog files
137.62	The APT frequency of the satellite.
NOAA 10
NOAA-10
137.5
NOAA 11
NOAA-11
137.62
Meteor 2-16
M2-16
137.3
Meteor 3-3
M3-3
137.85

The first entry is the name of the satellite you want to include in the tracking program.  It's spelling must match EXACTLY, its corresponding entry in the file you've downloaded from the bulletin board (it is also case sensitive).

The second line contains the spelling as you wish it to appear in Bird-Dog.  Note that these names must conform with DOS file name conventions, since they are used to create acquisition window files.  The names may not contain any spaces and should be 8 characters or less in length.

The third line contains the APT frequency of satellite in Mhz.  The current frequencies for the active weather satellites are:
NOAA 9	137.62
NOAA 10	137.50
NOAA 11	137.62
METEOR 2-16	137.3
METEOR 3-3	137.85

To run the program KEP2BD
	syntax:		KEP2BD	argl	arg2

where argl is name of satellite list (BIRD_LST.DAT)
arg2 isname of the log file containig ephermis data.

The program will read the list file and then begin processing the log file.  If a satellite is found in the log file, its Keplerian elements will be extracted and appended to the BIRD.DAT file, along with its APT frequency from the BIRD_LST.DAT.  A typical BIRD.DAT file follows:

_____________________________________________________________________
NOAA 9            137.62
1 15427U          89196.47764042 0.00000488           28734-3 0  4043
2 15427  99.1448 183.9754 0014425 233.1046 126.8803 14.12086380236448
NOAA 10           137.5
1 16969U          89200.21509624 0.00000598           28162-3 0  2513
2 16969  98.6366 230.0955 0013415 153.2927 206.8943 14.23090983148495
Meteor 2-16       137.4
1 18312U          89197.05155044 0.00000219           18868-3 0  2913
2 18312  82.5532 196.6614 0012858 109.1610 251.0911 13.83492947 96506
Meteor 2-17       137.4
1 18820U          89197.08879468 0.00000215           18415-3 0  1310
2 18820  82.5437 257.5868 0016069 184.3558 175.7471 13.84183932 73685
Meteor 3-2        137.85
1 19336U          89198.88838834 0.00000391           10000-2 0  2175
2 19336  82.5439 153.9460 0018931  69.3292 290.9789 13.16855311 46958
NOAA 11           137.62
1 19531U          89199.89876582 0.00000494           29490-3 0  1061 2 19531  98.9414 143.7651 0012043 138.5761 221.6325 14.11072946 41948
Meteor 2-18       137.3
1 19851U          89195.09296800 0.00000116           10000-3 0   554
2 19851  82.5222 137.8092 0013064 231.1896 128.8588 13.83817828 18807
_____________________________________________________________________
   4. After the data file has been modified, copy it to the directory where the Bird-Dog distribution files are located. The next time Bird-Dog is started, the new ephemeris data will be used.


Modified NASA Prediction Bulletin Format

The following is a description of the foramt used by NOAA na dNORAD to stroe satellite ephermeris data.  The format has been modified slightly to include th APT frequency of each satellite.

Data for each satellite consist of three lines in the following format:

AAAAAAAAAAA       ***.**
1NNNNNU NNNNNAAA NNNNN.NNNNNNNN +.NNNNNNNN +NNNNN-N +NNNNN-N N NNNNN
2 NNNNN NNN.NNNN NNN.NNNN NNNNNNN NNN.NNNN NNN.NNNN NN.NNNNNNNNNNNNNN

Line 1 
Column      Description
01-11       Name of satellite
19-24      APT frequency   [*** This must be added byuser ***]

Line 2 and 3 are the standard two line orbital element set format identical to that used by NASA and NORAD.  The format description   
is:

Line 2
Column   Description
01-01    Line number of element set.
03-07    Satellite Number
10-11    International designator (last two digits of launch yr)
12-14    International designator (launch number of year)
15-17    International designator (piece of launch)
19-20    Epoch year (last two digits of year)
21-32    Epoch (julian day and fractional protion of day)
34-43    First Time Derivative of the Mean Motion or 
         or Ballilstic Coefficient (depending on ephemeris type)
45-52    Second Time Derivative of Mean Motion (blank if N/A)
54-61    BSTAR drag term if GP4 general perturbation theory used.
         Otherwise, radiation pressure coefficient.
63-63    Ephemeris type
65-68    Element number
69-69    Check Sum (Modulo 10)
         (letters, blanks, periods = 0; minus sign  = 1)

Line 3
Column   Description
01-01    Line Number of Element Data
03-07    Satellite Number
09-16    Inclination (Degrees)
18-25    Right Ascension of the Ascending Node (Degrees)
27-33    Eccentricity (decimal point assumed)
35-42    Argument of Perigee (Degrees)
44-51    Mean Motion (Degrees)
53-63    Mean Motion (Revs per day)
64-68    Revolution number at epoc (Revs)
69-69    Check Sum (Modulo 10)

Line 4
1-5 APT frequency (***This must be added by user***).

All other columns are blank or fixed.   

