To use TDoA, verify the target receivers are installed with Option 400 and 401. Click the TDoA menu button to display the TDoA menu as shown in Figure: TDOA Settings and Control. See TDoA Locate (Option 401) for more information regarding the TDoA menu.
TDOA Settings and Control
1. Start Button
2. Hostname Entry
3. Channel Entry
4. Reference Level Entry
5. Preamp Checkbox
6. Generate Report Button
7. TDoA Menu Button
8. Averaging Checkbox and Entry
9. Capture Bandwidth Entry
10. Center Frequency Entry
TDoA Measurement Procedure
Use the following procedure to perform a TDoA measurement.
1. Enter IP addresses for three RSMs in use. After entering each address, the program will attempt to communicate with the RSMs. The background color of the IP Address box will change to green if the unit responds and has the required options (400 & 401). It will turn red if no response or options are missing.
2. If the RSMs are multi-port units, select the antenna channel, otherwise leave Channel at '1'.
3. Optionally set the Reference Level. Or, the program will auto-detect the appropriate reference level.
4. Optionally, check the Preamps box to turn on. This is subject to normal spectrum analyzer control. If the reference level or attenuation are too high, the preamps will not turn on.
5. Set the center frequency of the RF signal that is being used for geo-location.
6. Set an appropriate capture bandwidth. Wider captures use more data and the measurement is slower, but wider captures have greater time resolution so the accuracy of the TDoA measurement improves. Do not set the capture bandwidth wider than the occupied bandwidth of the signal.
7. Set the desired measurement count for averaging. 3 is an appropriate rough estimate; 10 is a good typical number.
8. Press the Start button to begin data acquisition. The initial estimate takes longer as each RSM has to set up. Subsequent averaging measurements will be quicker. How long it takes to complete depends on many factors, such as the network connection communication and the capture bandwidth. This will continue until the measurement average count is obtained, or the user presses 'Stop' to cancel. Results for each measurement will be displayed.
9. Press the Generate Report button to show measurement details as shown in Figure: TDoA Report.
