***************************************** ***************************************** ** ** ** ** ** GPS-LOG ** ** ** ** ** ***************************************** ***************************************** ******************************************************************* If you are upgrading from version 1.9 or lower make certain to read the READ-UPG.TXT file. ******************************************************************* The GPS-LOG program has been developed with a non-competitive glider pilot in mind, but can be used in any situation that GPS position data are available for logging. Current position, speed, track on ground, distance and course to a waypoint destination as well as needed altitude are displayed in real time. A "moving map" display shows the path travelled as well as waypoints created in flight overlayed on a pregenerated map. A zoomed diplay mode designed for thermalling is usefull for centering thermals, observing drift and estimating wind aloft. Wind can be also obtained from straight flight data. Needed altitude can be corrected for winds and glider polar. The associated VIEW-MAP program is used to preview the maps one generates, and to display the path flown. The programs are designed to run on any DOS machine with a CGA (or better) display, but have been specifically designed for HP100LX palmtop computer. My understanding is that this program was also run on a Zeos computer with satisfactory graphics performance, and on HP95LX in the text only mode. This was however at very early stages of program development and things may have changed since (program size, graphics initiation). DISCLAIMER AND AGREEMENT: Users of GPS_LOG and associated software must accept this disclaimer of warranty. If you do not accept this disclaimer, do not use GPS_LOG. "GPS_LOG IS SUPPLIED AS IS. THE AUTHOR DISCLAIMS ALL WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, THE WARRANTIES OF MERCHANTABILITY AND OF FITNESS FOR ANY PURPOSE. THE AUTHOR ASSUMES NO LIABILITY FOR DAMAGES, DIRECT OR CONSEQUENTIAL, WHICH MAY RESULT FROM THE USE OF GPS_LOG AND ASSOCIATED SOFTWARE, EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES." This applies especially to any features of the program where estimates of factors that affect flight safety (like wind and required altitude estimates) are concerned. Such features are highly inaccurate and subject to many errors both human and instrumental. GPS_LOG and associated software can be freely distributed and shared with others as long as no charges of any kind are made. The programs in this package are free, but not in the public domain. (C) COPYRIGHT 1996,1997,1998 Henryk Birecki, All rights reserved. CONTACT: for sending comments, requests, bug reports : e-mail : birecki@hpl.hp.com FILES: GPS_LOG.EXE - inflight logging and display program. VIEW_MAP.EXE - view and preview maps. GPS_LOG.LGO - Binary display file used for program initiation GPS_LOG.MXP - Binary map file used for program initiation. This file can be customized by the user by renaming any of theMXP files (see below) to this name. GPS_MAP.SMB - set of symbols for map generation and a cursor. This file can be supplied externally, or either program will build a default one. If you want something different - contact me. GPS_DEF.SMB - default set of symbols for map generation and a cursor. This file would be generated as GPS_MAP.SMB if GPS_MAP.SMB did not exist. WAYPOINT.DTA - ASCII file containing set of waypoints that can be selected for destination by the GPS_LOG user. You can change this file in flight. In-flight generated waypoints are appended to this file, so you should keep a clean backup copy handy. GPS_INFO.NFO - ASCII file containing set of notes. This is a default name for the notes file. You can change this file in flight. xxxyyyzz.MAP - ASCII files containing map information. The extension must be MAP. These files are modified by the program if you add waypoints in flight. xxxyyyzz.MXP - binary files containing map images. The extension must be MXP. abcdefgh.PLR - file containing polar data for your glider.You have to create your own. The one distributed here is valid for a DG100 at 30kg/m2 loading. GPS_LOG.ICN - an icon file for the HP100LX Applications Manager. DEMO_GPS.EXE - a useless program other than to show you how the movingmap display looks in action. You need to answer a couple of standard start-up questions before the map shows up, press F5 and select FIRSTMAP.MAP, cursor starts moving, map moves a couple of times before it runs out of range, then press Alt-Q to exit the program. GPS_LOG.INI - if not present this file is generated when you quit the program. (see below) GPS_IGRF - file containing geomagnetic model parameters. ****.ZIP - a couple of sticky key utilities you might find useful. They are not my software and I take no responsibilty for them. Personally I am using the stay100 from autoexec.bat. ALLSYMBL.MAP - a map you can load to see the symbols. Note that symbol # 8 defaults to symbol # 1 because there are only seven symbols in the GPS_MAP.SMB file. The other symbols are created dynamically when you "drop" a waypoint (see below). All the above files have to be in the same directory. The file for logging navigational data can be placed anywhere you like, but keep the pathname to less than 49 characters. Logging can be disabled if you enter "*" as the first character of the name. At this point the name "igc" is reserved (I may implement IGC data storage format in the future) GPS_LOG AND the HP100LX: ========================= It is strongly recommended that on the HP100LX you run the GPS_LOG program from the application manager, and that you put an inverted exclamation point(this can be entered by pressing[Fn][Filer]) in it's COMMENT line. When this option is active it prevents you from task switching from the DOS application. If you do it accidentally, you lose your serial port connection and the log file (go complain to HP). You should also expand your text display by using Fn-ZOOM to get largest possible characters for the text display. The typical path line in the application manager should look somewhat as follows: a:\glider\gps_log.exe |350 where "a:\glider" is your particular directory, and "|350" assigns 350 kB of memory to the program. All testing on the HP100LX was done under such conditions. You can also run the program in the native DOS of the HP100LX (see the "Terminate All" mode in the manual). You will get best program performance in that mode. You should also run in this mode if the program hangs when run from the Application Manager. It is also recommended that you use one of the public domain sticky key utilities that make the [Alt] and [Ctrl] keys behave like the [Shift] key, so that you do not need to press two keys simultaneously. Two of such utilities are distributed as zipped packages under the file names of FIXKHP10.ZIP, and STAY.ZIP. They are typically available on sites that distribute palmtop software. I also observed that HP100LX (I do not know about the 200LX) can get into a state which causes "Internal stack overload" if data are coming in from the GPS without being handled. This has nothing to do with this program and can happen whether you run GPS_LOG or not (even while rebooting the computer). I always connect the GPS unit after I answered all the initial questions asked by the program and turn it off before exiting the program. Running GPS_LOG ========================= The GPS-LOG.EXE uses COM1: to connect to the GPS. It connects at the standard 4800 baud. These parameters can be preset by editing the INI file. It accepts four kinds of standard NMEA sentences RMC, GLL, GGA and VTG, and the Garmin proprietary RMZ sentence. You can switch between RMC, GLL-VTG, and GGA-VTG combinations from within the program. I developed this program with a Magellan Meridian GPS and I know it works with it. I know it also works with Garmin 12XL. If you have problems with a different kind of a GPS unit please set the program to record all sentences in it's raw form (answer NO to the first question it asks you after you name the logging file) and send me the resulting log file. I'll try to get it working for you. If you see asterixes "*" in the displayed data it means that the data is outdated (either GPS unit sent you data with time not updated, or it has been a "long" time since it sent any position data at all) This program is somewhat experimental, and not all the bugs may have been completely worked out. Some of its features are more of debugging tools than something really useful. At any time you can press key F1 to get a complete list of meaningful keys and their functions. The help screen looks as follows Alt+Q to quit Dest. list F2 Dest. file AltF2 Now->dest. F3 Dest toggles +=0._- Where to AltF3 Landing sites F4 Dest. on/off F7 Wind correct. F10 Set polar F9 x-wind (cmpss) Alt-H (dest.) Alt-W Rst.drift Alt-B Deviation Alt-D NMEA toggle AltF6 Notes Alt-N Get a map F5 Map trhld Alt-R Toggle zoom AltF10 Re-track AltF7 Expand map Alt-+ Contract Alt-* Center map Alt-C Save map Alt-S Zero time Alt-M Time zone Alt-Z Toggle units Alt-U Cmp.speed Alt-O Log comment Alt-T Save freq Alt-F If you chose the help to be displayed in two screens you will also see: Speed algort. Alt-P , Data sets Alt-G , File Re-track ShftF7 Info Page Alt-I , Toggle graphics F8, Notes File Shft F2, Flip map Alt-5. There is also an "undocumented" feature for on the ground "what-if" testing at Alt-F1. It allows you to define current position. A bit clumsy, but may be very instructive particularly if used in conjunction with Alt-F3 which defines destination (or F2). Alt-F6 toggles between RMC, GLL-VTG, and GGA-VTG recognition. Alt-G is used as an efficiency optimization tool for VTG-GLL decode recognition. the value of 4 (default) works well for Meridian. Value of 1 ought to work for every unit. Alt-F controls how often data are logged to file. Should you enter 5, then every 5th NMEA datum is logged to file. Alt-Z is used to specify local time offset. It is better to set it in the INI file, as a change while the program is running will result in incorrect elapsed time, and a shift in the logged times. If the local time offset is 0, "UTC" is displayed in the time string. Otherwise, "LCL" is shown. Alt-M resets the stopwatch. Alt-U toggles display units. You have an option of the following unit pairs: (knots, miles) (miles per hour, miles) and (kilometers per hour, kilometers) Alt-D allows you to enter magnetic deviation. The program computes deviation using a public domain geomagnetic model which should be good enough for most applications. In a few years you may want to change the geomagnetic model parameters file from a National Geophysical Data Center Server. The file should contain only one model. Once you enter deviation, the computation is disabled.You can reanable computation by entering 999 for the deviation. You can also enter -999 to allow the PC to get its information from the GPS if you use one that computes deviation. Alt-T is used to add comments to the log file. It will appear in the file as: REM,"your comment". The parantheses are there to allow for comma delimited spreadsheet format to work. Comments can be up to 70 characters long. They are inhibited if you yse the IGC or Chicago Map format for saving data. GRAPHICS ========= F8 will get you to a graphics display, but you have to first get a map using key F5. That one will open you a screen that lists *.MAP files which you can load (see about the MAP format in another section) the files are sorted (see below), and you can get up to 20 files pers election page. You navigate on the page by pressing the arrow keys. Once you reached a file you want, press enter. If you want a next page - press "N", press "B" to go back to the beginning. Press "Esc" or "q" to cancel. If you cancel, you will get a blank map with your location in the center, but you will have to tell the computer what is the span of the map supposed to be ( from the center of a map to its edge). This can only happen after the first GPS position had been acquired. A special map file called !!!!!!!!.MAP is then created with a first circle radius of 20 km. The map is centred about the current position and can be used as any other map file. It is however created every time anew if you cancel map selection. The !!!!!!!!.MAP will appear at the end of the sorted list if you created after you run the program, and at the beginning if it existed beforehand. A temporary file called !!GPS!!#.$#$ is created for map sorting purposes. The program erases it after map selection is done. Maps can be renamed (you cannot lengthen a name) from the selection window by highlighting a name and pressing Alt-R. The primary reason for this feature is to be able to save the !!!!!!!!. Map file before it is overwritten. When you rename a file the sorting order is lost (for that file only). In it's graphic mode the program displays path flown, and a blinking cursor at the current position on the user defined map. As current position approaches an edge of the map, the map jumps to bring the cursor to the center of the screen. As it jumps, you lose some of the previous path information (it can be retrieved with the Shift-F7 key if you are logging data, or with Alt-F7 from the track cache if it holds enough). You can change the threshold for the map jump using . The larger the threshold value the closer to the center of the map jumps occur. Threshold value needs to be in the 0.1-0.48 range. Alt-C centers the map around current position. Once a map is displayed Alt+ and Alt* will let you expand and contract the image by a factor stored in the ini file (default is 1.6). The displayed track image is lost (but not the waypoints), and the map is recentered. If you have commands to load binary map files in your *.MAP file you will get nonsense when you try to rescale. The default rescale factor is 1.6 and can be modified only by editing the GPS_LOG.INI file. You can retrieve track information from data that were logged by pressing Alt-F7 (from cache) or Shift-F7 (from file). Recall from cache retrieves last recorded track points first. Recall from file retrieves the track starting at the beginning of the flight. After a long flight it takes time to do this update on a slow PC like the 100LX. Because of that, recall from cache is stopped if any key is pressed. Retrieve from file is not interruptable. You can also modify the INI file so that the track information stored in cache is automatically redisplayed after each map re-scale operation. Alt-5 rotates the map 180 degrees. This feature is not available in the zoomed mode. In the orientation where North is at the bottom, binary maps will not be imported. Alt-S saves the current map display in a binary form. This is designed for saving a flight for future viewing by the View-map program. The Map is saved as is seen independent of the rotation state. The rotation information is lost. WAYPOINTS ============ Selection of the destination waypoint (F2) is done the same way as selection of the map except that pressing "B" moves you back only one page. The waypoints are not sorted, but if the waypoint file is sorted, they appear to be. Selecting a Waypoint also turns on the "to destination" data display. The name of the highlighted waypoint can be edited while the program is running by pressing Alt+R. You cannot lengthen the name by editing it. You can "shorten" it; the rest of the name is filled with spaces. There is a limit of 1000 waypoints that will be available for selection. There can be more in a file, but they will be ignored (that includes the waypoints "dropped" by pressing F3). You can change the file containing the waypoints by pressing Alt-F2. Program remembers up to five (settable in INI file) destinations that you selected using key F2. Once you select three destinations the newly selected one replaces the old one. You can toggle between them by using keys "0" (zero), ".", "-", "_", "=" and "+". The first four move you back, the latter move you forward. Pressing F3 selects the current position to be a destination waypoint, and adds it to the waypoint file with a name "waypoint x" where x is a consecutive number. Waypoint is also marked on the map using a small square with a digit or a letter, and a corresponding symbol is saved to the map file. You should edit the waypoint file at a later time to name the waypoint and provide the altitude. You should also edit the map file. Pressing F3 also turns on the "to destination" data display. You can set a parameter in the INI file which will cause the program to record the "dropped" waypoint, but not make it into a destination. Shift-F3 acts like F3, but data are stored to a temporary map file only. This file is erased each time program starts. The symbol used to displayed these waypoints looks like symbol @ in a circle. This is useful to mark thermals and other features that are not useful on subsequent flights. Alt-F3 can be used to define the destination waypoint from the keyboard. The program asks for the name coordinates, and altitude of the destination. If you enter the '*' character as the last character of the name that destination will be saved to waypoint file. Since this feature requires attention and many keystrokes it should not be used in flight. It is provided as a way to enter data to a waypoint file and for "emergency" in-flight use. It is also usefull on the ground in conjunction with Alt-F1 which allows for current position definition. F7 toggles destination display on/off. LANDOUT SITES and NEEDED ALTITUDES =================================== F4 works like F2, but will give you only the few closest landout sites (distance, course and field elevation data are displayed during selection). You must have acquired the first position data point for this key to become active, and you must have marked the landout sites in the Waypoint.dta file (or another one that you are using) with "^" to get any. F9 allows you to select a polar curve to use for altitude computation. If a data file is not available you will be asked for a default glide ratio to use in calculations. You can also change this default in the INI file. The data are fit to the equation: v_sink = a + b* speed^2 + c * speed^4 and the glide ratio is derived from this. There is no guarantee that your glider's polar obeys the above equation, though it ought to be a reasonable approximation. For safety's sake I suggest you build some reasonable air sink speed into the polar data. Otherwise you will probably be getting estimates for altitude that are overly optimistic. As the last step in selection of the polar you are asked if you want to use altitude corrected speed for calculations. If you set the speed computation algorithm to "-2" then that speed is displayed when you display computed speed. In graphic mode it is denoted by "P" following the number. This speed is wind dependent (if you correct for wind), so it may be bigger or smaller than you'd expect from just correcting the GPS reported speed for altitude effects. If everything were perfect this would be the speed that your speedometer shows. F10 toggles wind corrections for the calculation of estimate of the altitude needed to reach destination. You know when the correction is active because the destination data start with "To>" instead of "To:" and because the course will be displayed as (.e.g) "34L" (meaning turn 34 degrees left) rather than "168m" meaning magnetic course of 168 degrees. NOTES ====== Use Alt-N to select a location and display notes on it much as you do the destination waypoint selection. The default name for file containing notes is GPS_INFO.NFO. You can use any file that as extension NFO to hold your notes. Select that file using Shift-F2. You can display up to ten lines 39 characters wide of any information you choose. COMPUTED SPEEDS and their DISPLAY ================================= Alt-O toggles between altitude and computed speed display. Some GPS units do not output speed above certain value (Meridian stops at 99.9 for the RMC sentences, but keeps going for GLL-VTG combination), so a computed value may be displayed. For now, only the GPS provided speed is used for any computations. Alt-P asks what weighting factors to use for averaging (algorithm), and how many past positions to use for computed speed determination. This affects the averaging response time. In general the speed computation is not too accurate, mainly due to GPS position fluctuations and time measurement inaccuracies, but then the speed that comes from some GPS units may not be any better. In this mode computed speed is followed by "c" in graphic display. If you set the algorithm to "-1" then speed computation will attempt to compute indicated airspeed based on true ground speed and altitude reported by the GPS. In the graphic display this mode is indicated by "I" following the computed value. This should be the speed your speedometer would show in absence of wind. If you set the algorithm to "-2" then speed computation show the last speed used in needed altitude computations. If you allow altitude correction for that speed and use wind correction than this should show the same speed as your speedometer in perfect situation. In the graphic display this mode is indicated by "P" following the computed value. If polar values are not calculated because you do not request them, or you do not display destination data, then the program reverts temporarily to the "-1" algorithm. WINDS. ======= Keys Alt-H and Alt-W are used to get some information on the winds aloft. Alt-H will ask for compass heading, Alt-W will assume that you are heading to (pointing the nose of the glider at) the current destination. Both of these are using the GPS given speed and track over ground so you should wait till speed and course stabilize. Alt-H is also used to enter your own wind estimate. This will be used for any computations until you press one of these keys again. These keys work differently in the zoomed mode - see below. Each time you press one of these keys the crosswind wind component is computed. The program attempts to construct wind from two crosswind measurements which should be taken at two headings as orthogonal to each other as possible. Each time Alt-H or Alt-W is pressed the newly computed component replaces the one which is most collinear with it for wind computations. If the crosswind measurements were taken at less than 30 degrees apart you will see question marks next to the displayed wind. You can reset the two wind components by entering 999 after Alt-H. Subsequent calls will fill in the wind components anew. The crosswind displayed by the program should be relatively OK. The computed wind is highly subject to the "garbage in-garbage out" syndrome. I have tested it with "ideal" data and it seems to work OK. At this point I have no experience with it in "the field". Pressing Alt-W while the program is in thermalling mode (Alt-F10) results in wind data being substituted by data derived from variation of ground speed as you go around the circle. This is probably he most accurate way to determine wind using this program. The main sources of error in that case are your ability to keep the indicated speed constant and rotation of the thermal. Information on winds that you collect can be viewed by pressing Alt-I. In addition to other information you will get a table of most recently recorded winds (most recent first), and values for the wind currently being used for calculations. The table lists only winds obtained by thermalling or from two cross-wind components. TRIPMATE GPS: ============== GPS_LOG has a mode set through the INI file that allows an additional initialization process after log file selection. At this stage its sole purpose is to allow the TRIPMATE to be connected. If TRIPMATE mode is selected the programme will wait for the ASTRAL string to be sent by the GPS. Once it gets it will notify you and send the ASTRAL string back to the GPS to start its functions. It will then ask you if you want to send an initialization sequence to the unit. It turns on the RMC sequences to be output every 2 seconds. If you want to log data less frequently use Alt-F function to choose the frequency. While waiting for the ASTRAL string to come in, you can quit the programme (Alt-Q), skip GPS initialization (Alt-C), or send the initialization string (F2) and continue to wait. While the programme is running only the RMC and GGA sequences are enabled and set to output every 2 seconds. You can control which other sentences get re-enabled upon programme termination via the INI file. Note: The connector on Tripmate expects to be plugged into a computer, so does the cable that is supplied with HP100LX connectivity pack. If you experience problems then you probably need to use an adapter in between that switches pins 2 and 3. DATA LOGGING: =============== At startup the program suggests a name of the data logging file. This can be disabled by editing the GPS_LOG.INI file. The suggested name is of the form YYMMDD-X.GPS (year month day - consecutive number). Entering "*" at any place in the name will disable data logging. Once disabled, you cannot turn it back on without exiting and restarting the program. You can enter IGC as the file name. In that case GPS-LOG will use the International Gliding Comission compatible format for saving data. The actual file name will be the suggested name (above). A single "A" record of the form "AH_BV2400GPS_LOG" is written at the beginning and is followed by "B" records. You also have an option (INI file) of using a format which is compatible with Chicago Map program. The only caveat here is that under some (rather rare) situations you may get an invalid day of the year recorded (only if you use a local time offset to display time). The standard data logging format is a simple comma delimited one. It is designed for ease of use with popular spreadsheet programmes for data analysis, sorting ... There is an option (settable in the INI file) of enclosing all text in parantheses to make it more compatible with some such programs. The first line of the file contains UTM, or GPS at the beginning. This should not be modified. It is used by the VIEW_MAP program when the track is replayed using the Alt-T key, and by the GPS_LOG program when using the Shift-F7 key. Different formats should not be mixed in the same file when appending data. Otherwise unpredicatble results may occur. A special logging format compatible with Chicago Map programs can be selected by editing the INI file. While using that format no text nor comments are recorded. The program is not guaranteed to record every bit of information that GPS sends on the NMEA link. In particular it will ignore most data that come in while one is using various key activated functions. Once such an activity is finished, the programme looks for the most recent valid data, and continues from there. There may also be some interactions between the graphic system routines display interrupts and the data link interrupts that may render some incoming data corrupt. This should be however a rare occurence. ALTITUDE LOGGING: ================= The program can log altitude reported by the GPS unit. It can also record the altitude of dropped waypoints. Whether it does it or not is determined by the INI file parameters (see below). Altitude is recorded in feet. Only valid altitudes are recorded. The validity of altitude comming from GPGGA sentences is determined by the number of tracked satellites. The validity of the altitudes from PGRMZ sentences is determined by the fix parameter, and as such is suspect. The program looks first for the GGA sentences, and if these are not available, it looks for the proprietady Garmin PGRMZ ones. In principle it is possible to see both sentences recorded in one file. The time recorded in a log file with altitude is the time of last position fix from a GLL, GGA or RMC sentence. TIME LOGGING: ============= The time logged to file is the same as the one displayed on the screen. In the standard logging format, it is logged in the decimal format for ease of use with spreadsheet programs where one might want to plot data versus time. For the same reason the logged time does not start over from zero as one passes midnight but keeps on going with added multiples of 24 hours. ZOOMED (thermalling) MODE: ========================== The zoomed mode is really designed for thermaling. This allows you to temporarily zoom the map display to some predetermined resolution (INI file parameter) and then come back to the previous map display. Key [Alt-F10] toggles between the zoomed and unzoomed states. While you are in the zoomed states the track is still recorded to your original map view as long as the map does not need to be recentered. When you toggle the map state you automatically recenter the map. The zoomed state map span, expansion/contraction rate and map move margin are controlled by the INI file parameters and are independent of those for the main map. The map span is remembered while the program is running, but is not saved to file. While in the zoomed mode the waypoints you drop are saved only to the temporary map file and are lost when you exit the zoomed mode. The dots marking the track are slightly bigger in the for better visibility. While in the zoomed mode it is assumed that you are circling, and after the first circle the program starts looking for maximum and minimum speed in each circle. It interprets the difference as due to the wind. As you keep circling it averages the value of wind velocity derived from the minimum and maximum speed in each circle and displays it instead of the TOG: on the screen. Pressing either Alt-W or Alt-H will result in saving the value for future computaions involving wind. To reset the wind averaging press Alt-B while in the zoomed mode. The wind speed and direction thus derived, is sensitive to the averaging filters of your GPS unit. It is also sensitive to your ability of keeping the indicated speed constant while thermalling. In the zoomed mode map centering may seem a bit confusing at times. the program attempts to center on the center of last circle rather than on the current position. However, if the center was not yet established or the map needs to be recentered more than once in a circle, the program temporarily gives up and centers on the current position. Under some conditions there may be too little memory to run in the zoom mode. If this mode is allowed you get a message "ZOOMED MODE allowed" in the opening screen which tells you which NMEA mode is used initially. NEEDED ALTITUDE ESTIMATE: ========================= THIS DOES NOT TAKE INTO ACCOUNT VERTICAL AIR MOTION. If you are not asking for the wind correction then calculation is done based on the glide ratio calculated from the polar at the gps indicated speed. The reported altitude is a sum of destination elevation, 1000 feet for pattern and the distance/glide_ratio. If you ask for wind correction the glide ratio is computed based on the estimated airspeed which is derived from the gps provided ground velocity vector and the wind velocity vector. Furthermore the actual path required to travel is computed based on the estimated air speed, the wind and the course to the waypoint. If the required altitude is greater than 100000 feet (100kF) "NO GO" is displayed. The altitude estimate is displayed only for waypoints for which the waypoint elevation is known. For speeds less than 5 knots, the needed altitude defaults to "NO GO". This is done to avoid possible division by zero in the program. The 5 knots limit is arbitrary and was chosen because it is well below any realistic stall speed. You can select a different speed by appropriately editing your polar data file (see format above), but you cannot set it below 5 kts. This limitation is not imposed if you use a default speed independent glide ratio. Note that the computations are done based on the speed on the ground. these are going to be somewhat higher than the actual air speeds due to the altitude effects. This is the only possible factor in the whole calculation that errs on the safety's side as the indicated needed latitudes will tend to be a bit higher. However let this not lull you into a feeling of safety. This whole calculation is based on so many flimsy assumptions with respect to the air motion that it can be used as a very rough guide at best. In particular I would strongly suggest that you add some extra sink rate to your polar to simulate average down air motion. You can eliminate this "margin" by asking the program to use altitude corrected values for speed. This will be done if valid altitude was supplied by GPS. The speed used in glide ratio calculations can be monitored by setting the appropriate compute speed algorithm (-2) and displaying computed speed. UTM vs. Lon/Lat formats in MAP and WAYPOINT files: ================================================= All the examples below are given in the Longitude/Latitude format. It is acceptable to input data in the UTM format. Shown below is the field comparison: Lon/Lat Lat.deg , Lat.min , Lat.sec , Lon.deg , Lon.min ,Lon.sec UTM 400 , 0 ,0 , Northing , zone , Easting The zone is positive in the northern hemisphere and negative in the southern. The "400,0,0" are internal file constants and as such must not be changed. NOTES file format: ================== #Truckee Tahoe UNICOM 122.8 AWOS 118.0 Truckee base 123.3 Rwy: 19 Left, 1 Right, 9, 27 Tel#: (530)-587-6702 #Reno Reno Approach within 20 NM North 126.3 South 119.2 Control Tower 118.7 ATIS 135.8 #Stead AWOS 135.175 #Minden Unicom 122.8 Soar Minden (702)782-7627 High Country Soaring (702)782-4914 The item name line has to have "#" as the first character. The name item line is followed by up to 10 lines of any information you want to display on the screen. Only 39 characters per line are read and displayed. WAYPOINT.DTA format: ==================== Aerial Cableways,35,51,30,117,7,0 ^Air Sailing,39,52,30,119,42,0,4300 Alpine County,38,44,30,119,46,0,5867 Alturas,41,29,0,120,33,30,4375 ^Angwin (Parret),38,35,0,122,26,5,1848 Austin,39,28,0,117,12,0,-1 Melbourne,400,0,0,5772050,-55,334942,1,M This is a simple comma delimited ASCII file. The read algorithm is not very forgiving, so do not make mistakes. No comments ... are allowed. The name of the waypoint is followed by it's latitude, longitude and altitude. Only the first 19 characters of a name are displayed by the program. Altitude is in feet(or meters), and the longitude and latitude in degrees, minutes, seconds. You can use floating point format (the absolute values will be added deg+(min+sec/60.)/60. ). To indicate south latitude put "-" in front of latitude degrees. To indicate east longitudes put "-" in front of longitude degrees(no spaces in either case). Longitudes must be in the -180 to +180 range, and latitudes in -90 to +90 range. For UTM coordinates see above. If you do not know the altitude then enter -1 (or enter nothing after longitude seconds, not even spaces) in the above examples both Austin and Aerial Cableways waypoints have no known altitude. If you want to enter elevation in meters add ",M" after the number as in Melbourne example above. The caret "^" as the first character identifes a landing site. It is not displayed in the destination waypoint selection listings, but is used for the closest landouts search. MAP file format: =============== This is also an ASCII comma delimited file, but with many more possibilities. Comment lines are allowed and denoted by ";" as the first character in the line e.g.: ;This is a comment ; and another Comments can appear any place in the file. The first meaningful line in the file has to look as follows: 38,0,0,118,0,0,40,0,0,120.5,0,0,10 Minimum latitude, minimum longitude, maximum latitude, maximum longitude, and first circle radius in miles (more about this later). ****** MAP FILE FORMAT CHANGED between version 1.9 and 2.0 ******* * * * in version 1.9 and lower minimum longitude and maximum * * latitude are switched. If you are upgrading you need * * to edit your map files to use with the new version. This * * is the only change that needs to be made. * * * ****************************************************************** * * * Additional changes were made in version 2.4.2.0 * * old files will work with new format, but read below * * * ****************************************************************** For versions 2.4.2.0 and later, the format of the first line was extended to the following: 38,0,0,118,0,0,40,0,0,120.5,0,0,10M,90.0 In the line above "M" indicates that all circles and arc radii in this map are specified in miles. Change it to "K" or "N" if you want to use kilometers or nautical miles. The number following it specifies the absolute scale of the map before any expansion or contraction. This is used on to determine whether controlled display symbols are hidden or not (see below). It does not matter what units are used for this number, but if you are displaying maps in the zoomed thermalling mode then you should enter here the larger of the north-south or east-west distance ( determined by the first 12 parameters on this line ) expressed in status miles. The parameters described in paragraph above are optional. If the circle / arc unit character is missing, statute miles are assumed. If the absolute map scale parameter is missing, program just counts the number of contract/expand keypresses. Remember that in the southern and east hemispheres sign is important in determining which is minimum and which is maximum. The positional data have to be again given in degrees, minutes and seconds, but these do not have to be integers so you can simply set minutes and seconds to zero. Otherwise conventions are as for the waypoints file. Typically you will want to have the min/max settings such that they do not encompass all the points on the map. As the map moves, new points will show up, you can change the scale of the map using Alt + and Alt * keys. The following lines contain map information: 39,52,30,119,42,0,1,Airs Above line places symbol number 1 at latitude 35deg52.5' N and longitude 119deg 42' 0" and labels it underneath with a legend "Airs". If you do not want a label to appear you must put a comma in it's place, e.g.: 39,49,10,120,21,0,4,, would place symbol # 4 at the location of Nervino airport, but not label it. If the symbol number is unavailable the program defaults to symbol #1. If you want circles drawn around the symbol place periods as the first characters of a legend, e.g.: 38,44,30,119,46,0,2,.Alp 38,15,40,119,13,20,6,..BrdgP 39,11,30,119,44,20,2,., will place one circle around Alpine and Carson airports (Carson is not labeled just symbol #2), and two circles around Bridgeport. You can also draw circles with arbitrary radius around a symbol with, or without circles of predetermined radius. The format for this is to enclose the value for the radius in miles between characters "@" and "M" and place them AFTER (or instead of) the periods. You can have multiple circles. The limitation is that from the first "." or "@" you can have no more than 38 characters on a line. Here are a couple of valid examples: 38,44,30,119,46,0,2,.@50.5MAlp a 20 (default) and 50.5 miles radius circles around Alpine 39,11,30,119,44,20,2,@30M@50.5M, 30 and 50.5 miles radius circles around Carson with no symbol Folowing the label you may add information as to whether the symbol will be displayed or not depending on the number of rescale state of the map. You have to provide two coma separated numbers 38,59,0,119,45,0,2,Mndn,0,2 or 38,59,0,119,45,0,2,,0,2 both of them will place a symbol at Minden position, but the second will not place a label. If you do not specify absolute map scale in the first line of the map then these numbers are interpretted as an integer rescale state (number of times you pressed Alt-+ less the number of Alt-* presses), otherwise they are interpretted as minimum and maximum absolute map dimension for showing the symbol. In the example above (absolute map scale was not given) the symbol will be placed only for three expansion states: original (0), expanded once (1) and twice (2). Negative numbers are used for contractions 38,59,0,119,45,0,2,Mndn,-1,2 will also show Minden on a once contracted map. If the first line was 38,0,0,118,0,0,40,0,0,120.5,0,0,10M,130 and the expansion factor was 1.6 then 38,59,0,119,45,0,2,Mndn,90.,200. would cause symbol for Minden to be displayed only at the original map scale (number of contractions=number of expansions). Circles around symbols are drawn irrespective of the rescale state. If you do not provide the absolute map scale the rescale factor is not taken into account at all. The program simply counts the number of times you pressed the keys. Otherwise the scale of the map is being kept track off, as you press the expand and contract keys. Negative (and zero) symbols cannot be followed by a legend. Symbols less than -10 are used to plot inflight waypoints without legends. They can be also added as regular symbols, but without legends. Symbols in the range of -10 and -5 are currently neglected, and lines are drawn with symbols in the range of -3 to 0.Two types of lines can be drawn. Course line - which is a continous,wide dashed line, and random solid lines. Symbol -4 is used to draw arcs. To draw a course line you define it's vertices using symbol #0 (no legend follows) e.g.: 39,49,10,120,21,0,0 would make Nervino to be one of the course line vertices. For the other lines symbol "-2" is used to start a line. Symbol "-1" results in a thin line drawn to the defined point from the previously defined point and symbol "-3" results in a heavy line. 38,1,0,118,16,0,-1 - no points previously, so start 39,49,10,120,21,0,-1 - draw a thin line to here 38,12,50,119,0,40,-3 - draw a thick line to here 38,15,40,119,13,20,-2 - start a new line from here 39,49,10,120,21,0,-1 - draw a thin line to here To draw an arc with a center at a given location you use symbol -4 and follow it by format similar to that of drawing arbitrary circles. The information is of the form: @ radius (in Miles), start angle, end angle M e.g.: 39,52,30,119,42,0,-4,@20.,280,230M@35.,180,100M In the example above two arcs are drawn around Air sailing. The first of radius 20 miles starting at 280 degrees (true) from Air Sailing, and ending at 230 degrees (true). The second has 35 mile radius going from 180 to 100 degrees. The arcs are always drawn counter clockwise. The limitation is that from the first "@" you can have no more than 38 characters on a line. All these can be freely intermixed, but for the lines being drawn in the order that points appear. The lines below are an example of an intermixed set of commands. 38,44,30,119,46,0,2,.Alp 38,1,0,118,16,0,5,Baslt 39,49,10,120,21,0,4,Bkwrt 39,49,10,120,21,0,0 39,52,30,119,42,0,-4,@20.,280,230M@35.,180,100M 38,12,50,119,0,40,1,Bodie 38,15,40,119,13,20,6,..BrdgP 39,11,30,119,44,20,2,Crsn 38,36,0,119,29,0,5,Colvl 38,59,0,119,45,0,2,Mndn,0,1 39,56,30,118,44,30,1,Falln 39,56,30,118,44,30,0 38,1,0,118,16,0,-1 38,50,0,119,24,0,4,Farias 38,36,10,119,0,30,8,Hltn 38,12,50,119,0,40,0 39,49,10,120,21,0,0 39,49,10,120,21,0,-1 38,12,50,119,0,40,-3 38,15,40,119,13,20,-2 39,49,10,120,21,0,-1 Placing "#" as the first character of the line will cause the computer to store currently displayed map to a file name e.g.: #fewpoint.mxp Placing "^" as the first character of the line ^firstmap.mxp will cause the computer to load a binary map from filename and add it to the present map. This is OK to do if the scales of both maps are the same, otherwise you get a nonsensical map. The loaded map is placed at the proper position. This feature is not available while map is rotated so that North is not at the top of the map. abcdefgh.PLR polar data file: ============================= Like in the other files the format is not forgiving. Typical file may look as follows: DG 101 polar data, low wing loading, up to 100 kts - a comment 0, 33 see description below 44.3,1.17 54,1.36 65.3,1.94 75.6,2.8 81,3.30 91.8,4.51 95.6,5.05 Done with data Program calculated things go below 3 calculated coefficients-high order first 3.298E-08 1.861E-04 6.103E-01 calculated coefficients-end Fit Results: speed sink L/D 40.0, 0.99, 40.3 45.0, 1.12, 40.1 50.0, 1.28, 39.0 55.0, 1.48, 37.3 60.0, 1.71, 35.1 65.0, 1.99, 32.7 70.0, 2.31, 30.2 75.0, 2.70, 27.8 80.0, 3.15, 25.4 85.0, 3.68, 23.1 90.0, 4.28, 21.0 95.0, 4.98, 19.1 100.0, 5.77, 17.3 105.0, 6.67, 15.7 110.0, 7.69, 14.3 115.0, 8.84, 13.0 120.0, 10.13, 11.8 125.0, 11.57, 10.8 130.0, 13.18, 9.9 135.0, 14.96, 9.0 140.0, 16.93, 8.3 end results The first line is a comment line. You can put anything that is meaningful to you. This comment line is followed by a line which has to start with either 0,1 or 2 (weight exponent) followed by any comment you want after a space or a coma and an optional value for the speed below which no altitude computation is done and "NO GO" is displayed (default is 5 kts). The coma must be immediately after the weight exponent. Additional comment can follow the minimum speed. The weight exponent changes the way the polar curve coefficients are calculated. 0 gives equal weight to all points, 1 and 2 progressively weight high speed data less. This line is followed by pairs of: speed, sink speed - in knots coma or space delimited. You need at least 5 pairs (more is better computer will complain with less than 4). These are used for developing a polynomial fit to predict the sink rate at any speed. You need to follow the last pair by any comment line. For cosmetic reasons you should add a "Done with data" line after the data pairs. Computer fills in the rest each time the data is processed. This information is there for you to know what to expect. I'd suggest you run the program once after creating the polar data, and look at the results before using it in flight. Note that as in the example above, the program does not know about stalls. Therefore L/D estimated at low speeds is overly optimistic. GPS_LOG.INI file: ================= This is a rudimentary ( order important) initiation file. Each parameter is preceeded by a line describing it's function. These lines have to be there for proper program function. Below are the INI file description lines followed by more details. ask/set log format: set to 1 if you want the program to ask you how to save logged data. set to 0 to record only good data and skip the speed and course information. set to 2 to record only good data with the speed and course information. set to 4 to record all data in raw format. Obviously these settings cannot be ORed. A bad setting will default to 1. comm port: serial port number baud rate: typically 4800 or 9600 depending on your GPS unit. NMEA code 0-RMC,1-GLLVTG, 2-GGAVTG: controls which NMEA sequence set is monitored by the program. gll-gvt collect number. Alt-G : used as an efficiency optimization tool for VTG-GLL decode recognition. the value of 4 (default) works well for Meridian. Value of 1 ought to work for every unit. check message length : set to 1 if you want the validity of data checked by message length if no checksum is provided. Defaults to no checking. units 0-M,Kts;1-km,kmh;2-M,Mph;3-N,Kts set to appropriate value to choose the initial units set. (N stands for nautical mile) display destination : set to 1 to start by displaying distance to destination number of destinations to save 1<=..<=5 controls the maximum number of destinations saved on the stack that you can scroll through using keys +_-.0= display comp speed : enables speed computation and display. speed algorithm -2<=..<=4. Alt-P -2 - speed used in last calculation of needed altitude for determining glide ratio from polar -1 - Indicated Air Speed computed based on GPS reported altitude and speed weighting factors for speed ageraging are shown below 0 - norm= 1,0,0,0... 1 - norm= .5,4,4,.5,.1,.... 2 - norm= 1,2,3,2,.6,..... 3 - norm= 1,1,1,... 4 - norm= elapsed time points for speed avg. Alt-P : number of points used for averaging map margin at move : distance from map edge (as fraction of span) at which the map is moved, track dot spacing : controls the minimum spacing between dots when plotting track (1-5) dot border width 0 to 4 : controls the size of dot used for track display. It is limited in software by the track dot spacing. map expansion factor : factor by which maps are expanded and contracted. if you set it to <=1 it will default to 1.6, if you set it to more than 10 it will default to 4. display factor 0.4<...<2.5 factor to control distortion of the map on the screen. It should be 1 on HP100LX and about 2 on standard PC screens. cursor refresh period 10=< .. controls how often the cursor blinks 20 - 40 works fine for HP100LX. position screen update period 0-30[sec] controls how frequently the numeric position data are updated on graphics screen. With a GPS sending data every second, the blinking of the display on HP100LX can be irritating. magnetic deviation : set to 999 to have program compute it, to a value you want to use or to -999 to use the GPS supplied value. geomagnetic model file : name of the file containing the geomagnetic model. Keep the whole pathname to less than 30 characters. altitude for deviation 1<=..<=6 : altitude (in km.) at which you want to compute magnetic deviation. deviation compute time gap [min]: time (in minutes) between magnetic deviation computations. It will not let you set anything in the 0<.. <10 range (0 or negative will cause the computation to take place each time valid position data come in) do not suggest file name : set to 1 if you do not want the program to suggest a name of file for data logging. data save frequency : determines how often data are saved to file. This is to limit the size of the files when not all the points are necessary. The larger the number the less frequently data is saved. value of 1 results in data being saved each time. Use quotation marks around logged text : set to 1 if you want quotation marks around text fields in the log file. Using Chicago Map save format : set to 1 if you want to use the Chicago Map format for saving data. waypoint data file at start : name of the file containing waypoints. local time offset : set the local time offset. If this value is not 0, data saved in Chicago Map format may have some incorrect dates around the first of the month. Switching it while program is running may cause a date offset withinin the file. don't replace destination with waypoint : set to 1 if you do not want waypoints dropped in flight to replace your current destination. Yoy can always get to them as they are stored in the waypoint file. Radius for distance computation FAI=6371.0 : Earth radius [km] used for distance computations. You can change this parameter within about 15 percent. UTM center scale factor; 0.9996 : scale factor used in UTM computations. should be 0.9996 for WGS84 and AMG (Australian) earth models. semi major axis WGS84=6378137; AMG=6378160 : UTM computation parameter. ellipsoid flattening WGS84=298.257223563; AMG=298.25 : UTM computation parameter. eccentricity WGS84=0.081819190843; AMG=0.081820179996 : UTM computation parameter. Display UTM not LON/LAT : set to 1 if you want to display/log UTM coordinates instead of longitude and latitude. Using Tripmate GPS : set to 1 if you are using a Delorme TRIPMATE GPS unit. Re-enable TRIPMATE on exit; add: ZCH-1,GSA-2,GSV-4,GGA-8,RMC-16 : Add the above values for codes you want reenabled on TRIPMATE upon program termination if you are using one. display current altitude : set to 1 if you want GPS reported altitude displayed when you are not displaying computed speed. display required altitude : set to 1 to display altitude required to reach destination. This is displayed only if Sltitude of the destination is known. correct for wind : set to 1 to start in the mode where required altitude takes wind into account. This correction will not function unless the program thinks it has acquired valid wind. default glide ratio 5<=..<=100 : default glide ratio to use instead of glider polar. Save GPS altitude to file : set to 1 if you want to record altitude to file. Record waypoint altitude : set to 1 if you want altitude of dropped waypoint to be recorded in the waypoint file. Not very useful (actually misleading) while flying, but usefull in a car. Display decimal minutes : set to 1 to display decimal minutes instead of minutes and seconds. North-South correction [minutes] : local correction to the GPS recorded values. East-West correction [minutes] : local correction to the GPS recorded values. Initial zoom map span [+- meters] : map span at which the program starts when toggled into the zoomed (thermalling) mode Zoom map margin at move : distance from map edge (as fraction of span) at which the map is moved while in zoomed mode. Zoom map expansion factor : factor by which maps are expanded and contracted while in zoomed mode. If you set itto <=1 it will default to 1.6, if you set it to more than 10 it will default to 4. ZOOMed track dot spacing : controls the minimum spacing between dots (1-5) when plotting track while in zoomed mode. ZOOMED dot border width 0 to 4 : controls the size of dot used for track display while in zoomed mode. It is limited in software by the track ZOOMed dot spacing. Initial zoom map expansion state : This defines the scale state of the zoomed map with respect to the main map. This is useful if you are using the main map while in zoomed mode and have symbol appearance governed by the expansion state. This setting is ignored if the map contains absolute scale information. Use main map for Zoom : In most cases you will set this to zero and use a temporary blank map while thermalling. However, you could use the main map with it's features if you set this parameter to 1. circles before drift computed 0<=..<=2 : Number of circles the program waits before attempting to compute drift while in the zoomed mode. Split help into two pages : Set to 1 if you want the help information to be shown in two (somewhat more readable) screens instead of one. Max.# of points in track cache: Number of track points the program will save in cache for re-display using Alt-F7. It defaults to 4000, or 300 (if you enter a number between 0 and 10). If you enter a number that is too large to fit in memory it will be limited by available memory. Force track update on rescale: Set to 1 if you want the track information to be recalled from cache each time you re-scale a map. Use IAS for needed altitude: Set to 1 if you want the computer to attempt to correct the speed for altitude in polars calculations. Notes data file at start : name of the file containing notes. Most parameters are changed by inputs to the program and are recorded to the ini file. If you have been using GPS_LOG program version below 2.4 then you need to do the following BEFORE YOU RUN THE NEW VERSION of the program: Erase your GPS_LOG.INI file (back it up). After you run the program for the first time, edit the new INI file to restore appropriate settings.