Release Notes for GPS Pathfinder Community Base Station Software, PFCBS Version 2.68 Contents -------- 1. Software Installation 2. PFCBS Software Security Key 3. Important Change in Recommended Logging Procedure 4. Converting Synchronized Measurements to Raw Measurements 5. Using PFCBS Software on Windows NT 6. Recommended Settings for PFCBS Version 2.68 7. Using PFCBS to generate Real-time differential GPS measurements 8. Differences between PFCBS v2.68 and PFCBS v2.67 9. Differences between PFCBS v2.67 and PFCBS v2.60 10. Amendments to the Manual 11. Technical Support Welcome to PFCBS software version 2.68. This release of PFCBS is compatible with the following Trimble Mapping System products: the GPS Pathfinder Pro XR, the GPS Pathfinder Pro XL, the GPS Pathfinder Professional (with Polycorder or MC-V data collector), GPS Pathfinder ProLite, GPS Pathfinder Basic, GPS Pathfinder Basic Plus, GPS Pathfinder BasicXL, and GPS Pathfinder GeoExplorer. See section 8 and 9 for details about program changes. NOTE: Trimble recommends a reboot of the PFCBS computer once per month. This action will optimize the operation of the computer and decrease the risk of memory errors when operating under Windows 95 and Windows 98. Please read these notes carefully. You will find not only a list of enhancements and improvements in this release of the software, but also important notes and instructions that may not have been included in the manuals. Be sure to use the installation program (INSTALL) as described in Section 2 of this document. This file: README.268 appears with the Program INSTALL.EXE and the file PFCBV268.EXE on the release disc. 1. Software Installation ======================== If you have already installed a previous version of PFCBS and you wish to re-use the current configuration parameters with the newly installed program, then rename (on your hard disc) the file named PFCBS.CFG to the new name PFCBS.SAV. NOTE: If you use the PFCBS.SAV file, make sure the settings you have used are still compatible with the parameters recommended in these release notes. Recommended settings are described in Section 7 of these Release Notes. To install the new version, make sure your AUTOEXEC.BAT file has the line: SET PFCBS=C:\PFCBS PATH=%PATH%;C:\PFCBS\ Then, (after rebooting the system) at the C: prompt, type A:INSTALL (or B:INSTALL). After running the first time, PFCBS.EXE (version 2.68) will extract all the important parameters (Reference position, paths, GPS receiver setup parameters, etc.) from the PFCBS.SAV file and put them into the PFCBS.CFG file. The first time the new PFCBS program is executed PFCBS.SAV is renamed PFCBS.OLD. If you do not rename the PFCBS.CFG file to PFCBS.SAV, then the system will have a default configuration as outlined in the operator's manual or in these release notes. It is important to verify that the new feature antenna height and reference position are correct. Check the Base Reference Position: When operating PFCBS v2.68 for the first time, it is important to enter an accurate reference position for the GPS Antenna. This may be done by surveying in a location in WGS-84 or NAD-83, height above ellipsoid, (do not use mean sea level height!) and placing the antenna over the location and entering an antenna height. This antenna height is called the true vertical height, and is the vertical distance from the reference mark to the phase center of the antenna. Alternatively, the antenna location may be surveyed in by connecting a survey grade receiver to the installed antenna coax and running survey post-processing software. Either way it is done, the average position screen will display the entered antenna position, which is the sum of the reference position and the antenna height. This screen will provide a cross check on the location of the antenna phase center. After a week or so the average position screen should display a difference between entered antenna position and measured to be less than 2 meters in north, east and up. If it is greater than 2 meters, it is important that the surveyed coordinates are checked, and perhaps re-surveyed. If you do not know the true location of the GPS antenna you may use the average position calculated by PFCBS, even though it is best to use a surveyed reference position. If you wish to use the average position calculated by PFCBS, first use the current position from the display as an initial guess at the reference position. If the entered reference position is not within 1 Km of the current position, no positions will be averaged. After a few hours, and once a day for a week, update the reference position with the average position. After a week, the averaged autonomous position (not differentially corrected) is usually, (but not always!) within a few meters of truth, depending on the current state of Selective Availability. Do not use the average position for reference position unless this reduced level of accuracy is acceptable. 2. PFCBS Software Security Key ============================== New purchases of PFCBS v2.68 are shipped with a new Software Security Key and activation disk for the PFCBS application. This is the same type of "activator" Software Security Key that is shipped with the GPSurvey product, Pathfinder Office, and PFINDER v2.50 and later. The new key allows one Software Security Key to be used for all Trimble Survey and Mapping products. The user simply activates the key for the applications they wish to operate with that particular key. Existing users of PFCBS v2.16 and earlier who update to PFCBS v2.68 can continue to use the older style of Software Security Key that was shipped with PFCBS v2.16 and earlier, however, the older key 18305-00 cannot be activated to operate Pathfinder Office or PFINDER v2.50 and later. Updates of PFCBS v2.68 sent to owners of PFCBS Software Support Agreements will not automatically include a new Software Security Key. *Contact the Trimble Technical Assistance Center (TAC) at 800-SOS-4TAC if you wish to exchange your old PFCBS key for the new "activator" PFCBS Software Security Key. 2.1 New PFCBS users ------------------- Install the Software Security Key on the PC parallel port and run PFCBS. If you wish to run Pathfinder Office or PFINDER v2.50 and later versions on the same computer, your security key can be activated with the activation disk that is included with PFCBS. Alternatively, your PFCBS key can be activated with the activation disk that is included with Pathfinder Office or PFINDER v2.50 and later. See the instructions below for activating and deactivating your PFCBS or Pathfinder Software Security Keys. 2.2 Existing PFCBS users (v2.16 and earlier) -------------------------------------------- Use the existing Software Security Key that was shipped with previous versions of PFCBS. Contact TAC to request an exchange of PFCBS keys if you wish to move application activations to a single key. 2.3 Pathfinder Office users --------------------------- If you wish to activate Pathfinder Office on the PFCBS Software Security Key, the Pathfinder Office activation needs to be transferred to the activation disk supplied with Pathfinder Office (P/N 30949-00) using the Pathfinder Office activation program. Then activate the PFCBS security key using the Pathfinder Office activation program. Note that PFINDER and GEO-PC upgrade activation disks cannot be used. 2.4 GPSurvey users ------------------ If you wish to run GPSurvey and PFCBS on the same computer, your GPSurvey Software Security Key can be activated with the activation disk that is included with PFCBS. Use the GPSurvey software to obtain an activation from the PFCBS Software Security Key. 2.5 Instructions for activating and deactivating the Software Security Key from DOS ------------------------------------------------ The program that does the actual activation, ACTIVATE.EXE, is a DOS program. Its interface is very terse. It can, however, be used to activate and deactivate products directly from the DOS command line prompt. To activate the security key, place the product activation disk in the A: (or B:) drive. The following instructions assume that the A: drive is used: a. Make the A: drive the current drive by typing A: b. Type the following at the command line to install a product: activate -i -a or the following to de-install a product: activate -d -a The -a option enables an ASCII message when the program terminates. c. If successful, the activate program displays: OK If not successful, the activate program displays: ERROR: n where n is one of the following error codes listed in the error code section below. Error Codes ----------- 1. Unable to locate activation disk (applicable only to GPSurvey) 2. Activation disk is write protected 3. Cannot read from activation disk (disk error) 4. Cannot write to activation disk (disk error) 5.(*) No installs remaining on this activation disk 6.(*) Cannot de-install onto this disk (would exceed maximum installs) 7. Original disk verification failed, may be a copy 8. Original disk verification failed, may be a copy 9. Not a valid GPSurvey security device (invalid internal codes) 10. Unable to read from security device (may be old black device) 11. Unable to write to security device (may be old black device) 12. Unable to update security device (device removed?) 13. Product already installed in security device 14. Product not currently in security device (de-install request) 15. Bad security device configuration (header indicates not valid) 16. Unknown product information retrieved from activation disk 17. Product information appears corrupt (bad checksum) 18. Unable to make password (for backup installations) 19. Password is not correct (for backup installations) 20. Old GPSurvey dongle scheme error (for old beta releases) 21. Old GPSurvey dongle scheme error (for old beta releases) 22. The erase confirmation, 'erase', was not typed properly (*) These messages also apply to restoring backup activations. When error 5 is encountered in the process of restoring a backup activation, it indicates that all the backup activations have already been used up. When error 6 is encountered in the process of restoring a backup activation, it indicates that all the original activations are still on the disk and restoring the backup activation would exceed the original installation count. 3. Important Change in Recommended Logging Procedure ==================================================== To help ensure the success of differential correction processing, please read this carefully. The details that follow can help both to avoid future differential correction problems and describe how you can increase the accuracy of results from your existing Trimble Mapping System. The Trimble Mapping GPS data collection products are continuing to evolve as GPS processing technology rapidly evolves in its ability to generate highly accurate position and time information. The Mapping product line currently includes the GIS Surveyor (using Maxwell-based 4000 Series survey receivers), the GPS Pathfinder Pro XR (replacing the GPS Pathfinder Pro XL, GPS Pathfinder Professional with Polycorder, the Professional with MC-V, and the ProLite), the GPS Pathfinder GeoExplorer, and the GPS Pathfinder Community Base Station. 3.1 Increased Accuracy and Multipath Rejection ---------------------------------------------- April 1997 saw a revolutionary increase in position accuracy that is possible with GPS systems. The introduction of Trimble's new Everest multipath rejection technology provides a new high-accuracy solution for code- based GPS mapping applications. By rejecting multipath signals before computing positions, the new GPS Pathfinder Pro XR with Everest provides up to 50% higher accuracy than previous Pathfinder mapping systems. 3.2 Synchronized Measurements ----------------------------- We recommend for PFCBS version 2.68 the use of the Synced Msmts setting. This will allow CBS owners to provide synchronized measurements to Pro XR and Pro XL users. To provide base data that is usable by PFINDER version 2.40 and earlier, a standalone utility named SYNC2RAW is included on the PFCBS version 2.68 diskette. Please look at the end of this section for more information on the SYNC2RAW utility program. 3.3 Recording Raw Measurements to the base file ----------------------------------------------- Raw Measurements contain code phase data which is not on the GPS integer second (not synchronized). This is identical to the base data recorded by 6-channel CBS systems or GPS Pathfinder 2-, 3-, and 6-channel rover systems. Although the measurements recorded by the 12-channel CBS are more accurate than the 6-channel CBS system's measurements, they are written in the same format as the 6-channel raw measurements for the sake of compatibility. When base data is logged with the Measurement setting it can be used by all GPS Pathfinder rover systems, Pathfinder Office, and any version of the PFINDER 2.xx software. 3.4 Recording Synchronized Measurements to the base file -------------------------------------------------------- Synchronized Measurements contain full pseudorange, carrier phase, and doppler data. Synchronized Measurements are the same type of measurements available from Maxwell-based 4000 Series survey receivers. The GPS Pathfinder 12-channel Community Base Station uses a Pro XR receiver and synchronized measurements in the base file to allow the GPS Pathfinder Pro XR or Pro XL rover system to achieve maximum positional accuracy. You must have Pathfinder Office or PFINDER version 2.50 and later (with MCORR400 or MCORR300 version 3.43 and later) to properly differentially correct against a base file that contains synchronized measurement data. 3.5 What you should do as a CBS owner ------------------------------------- If you record all base data as Measurements (Raw Measurements), notify your users that GPS Pathfinder Pro XR and Pro XL users cannot obtain positions which satisfy the accuracy specifications for their receivers. If you choose to log Synced Measurements (Synchronized Measurements) notify your users that they will need to use Pathfinder Office or PFINDER version 2.50 and later (with MCORR400 or MCORR300 version 3.43 and later) to properly differentially correct against a base file that contains synchronized measurement data. If they use PFINDER v2.40 or earlier (with MCORR300 version 3.04 or earlier) for differential correction, they must use the SYNC2RAW standalone utility program to convert synchronized measurements to raw measurements before performing differential correction with the base file. NOTE: Trimble recommends that CBS owners distribute the SYNC2RAW utility to users of their base data who do not have Pathfinder Office or PFINDER version 2.50 and later. Users can purchase a PFINDER to Pathfinder Office upgrade package. If transmitting real-time DGPS corrections, synced measurements must be chosen, no matter what kind of rovers are used. The RTCM formatted measurements are more accurate when synced measurements are used for their generation. All users can utilize the RTCM corrections which have been generated by a base station using synced measurements. 3.6 What you should do as a Pathfinder rover system owner --------------------------------------------------------- Pro XR and Pro XL owners: If the base data was recorded as Measurements (Raw Measurements), GPS Pathfinder Pro XR and Pro XL users cannot achieve specified accuracies with that base data. Contact your base data supplier to arrange for a Community Base Station that records Synced Measurements. If the base data was recorded as Synced Measurements, GPS Pathfinder Pro XR annd Pro XL users can achieve specified accuracies with that base data if a. Pathfinder Office or PFINDER version 2.50 and later (with MCORR400 or MCORR300 version 3.43 and later) is used for differential correction, b. A 12-channel PFCBS is used with Synced Measurements, c. A GPS antenna with a ground plane is used on the base station, d. The roving receiver must use a PDOP of less than 4 and be in a low multi-path environment. Non-Pro XR or Pro XL owners: When your base data is recorded as Measurements (Raw Measurements), you may perform differential correction as you have in the past. There is no change in the processing procedure. Independent of the receiver source (that is, no matter if a 6-channel receiver or a 12-channel receiver is used at the base), the differential correction program averages raw measurements over regular intervals resulting in some degradation to the rover position solutions. When your base data is recorded as Synced Measurements, you will need to: a. Use Pathfinder Office or PFINDER version 2.50 and later (with MCORR400 or MCORR300 version 3.43 and later) to properly differentially correct against that base data. OR b. Use the SYNC2RAW standalone utility program to convert synchronized measurements to raw measurements before using PFINDER version 2.40 or earlier to differentially correct rover data. See Section 5 of these Release Notes for information on SYNC2RAW. Users can purchase a PFINDER to Pathfinder Office upgrade package. HINT: You can determine the type of measurement data recorded in the base file by viewing the base file with the Pathfinder Office SSF Record Editor or the PFINDER Editor Module. The desired Raw Measurements will appear as records that begin with the letters "MMT". Synchronized Measurement data will be preceded by the letters "MHS" and "MDS:". 4. Converting Synchronized Measurements to Raw Measurements =========================================================== Mapping System products prior to the new GPS Pathfinder Pro XR system and the existing Pathfinder Pro XL system are not capable of collecting position data that is synchronous with the measurements recorded when PFCBS is set to Synced Msmts and a 12-channel receiver is used with the CBS. Pro XR and Pro XL systems are capable of collecting position data that is synchronous with the synced measurements recorded by 12- channel CBS systems. Differentially correcting Pro XR and Pro XL rover data against a base file that has synchronized measurements provides the best accuracy for rover positions. To allow CBS owners to provide synchronous measurements to Pro XR and Pro XL users, and to still provide base data that is usable by PFINDER version 2.40 and earlier, a standalone utility named SYNC2RAW is included on the PFCBS version 2.68 diskette. SYNC2RAW is available from your base station operator and on the Internet at: ftp://ftp.trimble.com/pub/mapping/bin/ Download and run the self-extracting zip file SYNTORAW.EXE to extract the SYNC2RAW program and README file. Users who do not have Pathfinder Office or PFINDER version 2.50 and later should use SYNC2RAW to convert their base data to raw measurements before using PFINDER version 2.40 or earlier to differentially correct rover data. Trimble recommends that CBS owners distribute the SYNC2RAW utility to users of their base data who do not have Pathfinder Office or PFINDER version 2.50 or later. Users can purchase a PFINDER to Pathfinder Office upgrade package. 5. Using PFCBS Software on Windows NT ===================================== In normal operation, PFCBS software synchronizes the PC clock to UTC time in order to open and close files on a very accurate schedule. Windows NT does not allow this synchronization to occur. Users of Windows NT should run PFCBS software from the command- line as follows: pfcbs -rxtime This will skip the PC clock synchronization step and begin to use UTC times derived directly from the GPS time of the receiver. IMPORTANT: Under Windows NT, the GPS receiver must be continuously operating and producing position fixes in order to reliably derive UTC time. 6. Recommended Settings for PFCBS Version 2.68 ============================================== Below are the recommended settings for the GPS Pathfinder Community Base Station version 2.68. These configuration items can be changed in the "Receiver Setup" sub-menus. These parameters are restored to the following values when the "Set All Defaults" sub-menu is activated. - Dynamics Code set to Static. - Elevation Mask set to 5.(see additional comments below.) - SNR Mask set to 6. (See additional recommendations below.) - PDOP Switch set to 6. - PDOP Mask set to 6. - Position Fix Mode set to Auto 2D/3D (Previously 3D manual. This is required for proper operation of RTCM message generation. For best results, all rovers must still use manual 3D or Overdetermined positioning mode.) - Set SV Health Action is now set to Heed Health (PFCBS version 2.12 was Ignore Health. (ALWAYS USE "HEED HEALTH".) Note: The Masks - SNR, Elevation, PDOP, and the position mode only determine what satellites are used in the position fix that is used by the average position program. The tracking of satellites is controlled by the following algorithm in the receiver: The tracking assignment is done on a section basis with section A given the first priority, section B given second priority, and so on. This continues until all four sections are exhausted, or the unit has used up all channels, whichever comes first. The four sections in descending order of priority are listed below: A) Track highest healthy satellites (according to almanac health page) that are above the user entered elevation mask. B) Track highest unhealthy satellites (according to almanac health page) that are above the user entered elevation mask. C) Track highest healthy satellites (according to almanac health page) that are below the user entered elevation mask and above 0deg elev. D) Track highest unhealthy satellites (according to almanac health page) that are below the user entered elevation mask and above 0 degrees elevation. The receiver, acting as a base station attempts to track all the satellites it can, however, only those satellites meeting the elevation and signal strength mask, health status and dop are used for a position computation. This prevents corruption of the position average by an unhealthy satellite. The following settings are recommended, but are not restored when the "Set all Defaults" in the receiver menu is activated. Local Time Offset is 0. Users PFCBS with Desqview and BBS software, sometimes called a Super CBS, may have batch programs that use the PC clock. This version of PFCBS sets the PC clock to local or UTC, depending on this variable and dependent of the time display format - local or UTC. Many batch programs require the PC clock to be set to UTC. If that is the case, use a local-UTC offset of zero (0). Logging Rates Menu - Position Logging Rate set to 5. - Measurement Logging Rate set to 0. - Synced Msmt Logging Rate set to 5. - Clock set to 0. - Velocity set to 0. Antenna Type Menu - Antenna Type set to Compact Dome or Compact L1. - Antenna Height set to 0. (When setting the reference position enter the height of the reference mark in WGS-84 and height above ellipsoid. The antenna height in meters is the height above the reference mark. Normally this value is set to zero and the antenna location is used as the reference position with no height offset. Output file path creates new directory if necessary. There is a warning before it does this. 6.1 Recommended Synced Msmt Logging Intervals --------------------------------------------- To ensure the best possible accuracy, the logging interval for synchronized measurement data at the base should be the same as the value you set for logging positions at the Pro XR or Pro XL rover receiver. For example, the base and rover logging intervals are both set at 1 second, or are both set at 3 seconds. The position logging interval at the Pro XR or Pro XL rover can be different from the synchronized measurement logging interval at the base, but rover positional accuracy may be degraded to greater than one meter from truth. This degradation occurs because some interpolation of base data during differential correction is required when base measurements are not recorded at the same GPS integer second as the rover positions. If the base and Pro XR or Pro XL rover logging intervals are different, you can improve the accuracy of rover positions by making the position logging interval at the rover a direct integer multiple of the synchronized measurement interval at the base. If you set the synchronized measurement logging interval at the base to 1 second then you will be able to use any logging interval at the rover. However, this will generate a file that, if allowed to run for several hours, may exceed the memory capacity of your data collector. If the base station data collector runs out of space you will not be able to differentially correct any rover data collected after the base file ended. A good compromise between accuracy and storage space requirements is to set the base at a 5 second Synced Msmt interval and with a Pro XL rover used at a 1 second interval. The extra inaccuracy caused by interpolation is on the order of 0.1 meters. When both memory capacity and accuracy is at a premium, the best option is a 5 second logging interval for synchronized measurement data at the base and a 5 second logging interval for positions at the rover. This is frequent enough to be practical at the rover and uses the default base logging interval which results in base files that are not too large, and does not incur the 0.1 meter interpolation innacuracy with a 1 second rover position interval. 7. Using PFCBS to generate Real-time differential GPS measurements ===================================================== Read section 7 for recommended settings of the GPS receiver. Normally, Port 1 on the PC is connected to the GPS receiver and Port 2 is connected to the modem or data radio. It is necessary to set the RTCM Output baud and format and return to the main menu before the new values are accepted. PFCBS V 2.68 has the provision to delay the data transmission after the CTS (clear to send) signal has been returned from a wireless modem. To use this feature select the submenu: Options - Serial Ports - RTCM Output - Options. Then enable the RTS/CTS/DCD (RTS - request to send, DCD - data carrier detect) feature by putting an X in the Radio Modem (Trimtalk) selection field, which removes the X from the Disable field. Then enter the desired CTS - Data delay in milliseconds. If you wish to keep the RTS line active for a short time after the data has finished, then enter a Trailing Delay time in milliseconds. Some modems require a carriage return to end the RTCM message. If yours does, then enter a Y in the Carriage Return field. If the state of the CTS line in your radio prevents the PC from sending data, a warning message will appear in the lower left window. If this happens, choose the “ignore CTS” selection in the Serial Port - RTCM Output - Options screen. If the modem does not return CTS within 20 msec., and CTS is set for the “Heed CTS” mode, then the current RTCM correction will not be sent out. 8. Differences between PFCBS v2.68 and PFCBS v2.67 ================================================== 8.1 v2.67 includes a bug where PFCBS occasionally would stop logging measurement data. This bug has been fixed in v2.68. 9. Differences between PFCBS v2.67 and PFCBS v2.60 ================================================== 9.1 Modifications have been made to the software to make it Year 2000 and GPS Week Number Rollover compliant in accordance with Trimble policy. This policy may be viewed at: http://www.trimble.com/y2kwnro/policy.htm 10. Amendments to the Manual ============================ Following are corrections to the list of part numbers in Appendix C of the manual: 10.1 PFCBS software on one 3-1/2 inch disk 26494-10 (correction) 10.2 PFCBS Security Key Activation disk 25235-01 (addition) 11. Technical Support ===================== We highly encourage you to submit inquiries by email or FAX, as these can be handled the most quickly. Inquiries received by email, FAX, or voice mail after our business hours will be handled immediately the next weekday. If you encounter difficulty while installing or using the PFINDER software you can reach a trained technician by calling the Trimble Technical Assistance Center (TAC). The TAC phones are answered from 6 AM to 6 PM Pacific Standard Time. A support technician will take your call, isolate your difficulty, and provide technical assistance. The Technical Assistance Center can be reached at Voice: 800-SOS-4TAC Fax: 408-481-6020 Email: trimble_support@trimble.com Internet: http://www.trimble.com/support If you are outside the US, you can call a regional telephone support line. The phone numbers are: +44-1256-760-150 (European customers) +64-3-339-1400 (Australian and New Zealand customers) +81-35-476-0880 (customers in Japan, Hong Kong, and Singapore) 11.1 Trimble Internet (FTP) Site -------------------------------- The Internet provides a way for you to quickly obtain daily satellite status reports, technical tips, almanacs (updated weekly), and other bulletins from Trimble. You should check the Internet on a regular basis for important information. Dear CBS Owner: Thank you for selecting the GPS Pathfinder Community Base Station. In order to ensure the highest level of service possible, we ask that you answer the questions below. The information will be held in strictest confidence. The name and address information will be entered into the Trimble Service database to ensure that you receive software updates and service bulletins in a timely manner. Under no circumstances will the information below be distributed outside of Trimble, unless you indicate that it is ok by checking the yes box in question 9. Feel free to copy the form as necessary. Some Community Base Station owners will find it convenient to send a copy right away with the correct address, user name, etc. Then to (re)send the complete form after their Community Base Station is operational. Please fax the form to Surveying & Mapping Customer Service at (408) 481-6020. If you cannot fax the form, the information should be mailed to the address below: ATTN: PFCBS Customer Service Trimble Navigation Building 9 880 West Maude Ave. Sunnyvale, CA 94086 Thank you again for purchasing a Pathfinder Community Base Station. We are confident that you will soon be collecting GPS based field data more efficiently and accurately than ever before. Community Base Station Owner Survey 1. Please supply the information below. This information will be used for the purpose of informing you about upgrades or new versions of software and firmware. Contact Name(s) Company/Department Mailing address City State ZIP Phone FAX CBS Receiver Serial Number(s) 2. Is your Community Base Station operational? If No, please answer questions 3-8 as best you can. Yes No 3. Is the base data that you collect available to the public in general? If No, please go to question 9. Yes No 4. Is there a charge or fee for your base data? If No, please go to question 6. Yes No 5. What is the charge (or the fee structure) for your Community Base Station data? 6. Should parties who wish to obtain base data: A. Send a blank disk and self addressed, stamped envelope? B. Call the CBS owner for more information? C. Download the data directly from a BBS? (Please add the BBS Phone Number and communication parameters) D. Other (Please explain) 7. What is the base data collection schedule? Monday UTC Offset? (Local-UTC) Tuesday Name of Time Zone Wednesday Start Time Thursday Duration Friday End Time Saturday Elevation Angle Mask_________ Sunday Data Collection Rate___________ 8. Are ‘special’ data collection hours available by request? Yes No 9. Would you like to be included on a list of CBS owners who are willing to share\sell data? Yes and it’s OK to publish my name on a list No 10. Interested in participating in a CBS Owners Users Group? Yes No PFCBS v2.68 Release Notes 07/20/99