weather satellite receiver

Weather Satellite Receiver

Description Version 1.1

VIERLING Communications GmbH

70351.202/20 - 1.1 – 20050112

VIERLING

Weather Satellite Receiver - 1.1 - 70351.202/20

VIERLING Communications GmbH Pretzfelder Straße 21, D-91320 Ebermannstadt Postfach 11 65, D-91316 Ebermannstadt Tel.: +49(0)9194 767175 Fax: +49(0)9194 767179 E-Mail: [email protected] Internet: http://www.vierling.de

© 2005 VIERLING Communications GmbH, Ebermannstadt All rights reserved. Any reproduction, further processing or dissemination of this document or its contents, whether in whole or in part, by any means is expressly prohibited without the prior written consent of VIERLING Communications GmbH. We reserve the right to make changes without prior notice. Please note that great care was exercised in the preparation of this text. However, VIERLING Communications GmbH does not accept any liability for any errors that might be present in the text.

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Contents

1. Safety instructions .........................................................................5

2. General information about the Weather Satellite Receiver .........6 2.1 Delivery scope for WEATHERMAN................................................7 2.2 Prerequisites...................................................................................7 2.3 Requirements for the Weather Satellite Receiver ........................7 2.4 Special requirements for the weather satellite antenna ..............8

3. Connectors and operating elements.............................................9 3.1 DC 9 V jack ......................................................................................9 3.2 Antenna input / Signal / Headphones..........................................10 3.3 Signal jack.....................................................................................10 3.4 Headphones jack ..........................................................................10

4. Displays and LEDs .......................................................................11 4.1 Power LED.....................................................................................11 4.2 Satellite active LED.......................................................................11 4.3 Receiver status LCD.....................................................................11 4.4 Volume...........................................................................................12 4.5 NOAA Weathersat Software.........................................................12

5. Specifications ...............................................................................15

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1. Safety instructions

General information This device was built and tested in conformity with DIN EN 60950-1 VDE 0805-1 and left our plant in perfect working order. To maintain this state and ensure safe operation, the user must heed the following instructions and warnings.

Transport The device should be transported only in its original packaging (to protect against shocks and impact). Condensation can occur if the device is brought from a cold environment into the room where it is to be operated. The device must be absolutely dry prior to being operated. Accordingly, an acclimatization period of at least two hours is required.

Setup Protect the device against direct sunlight and heat. The device should be operated only with the supplied (original) AC adapter. During a thunderstorm, do not connect or disconnect the data communications lines.

Repairs Repairs must be performed only by qualified personnel. Only use spare parts which will not change the safety features of the device. Any maintenance and repair of the device when it has been opened must be performed by a trained specialist.

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2. General information about the Weather Satellite Receiver

Weather and climate are natural phenomena which make up a big part of our daily lives. When monitoring local weather, parameters such as the air pressure, temperature, humidity, cloud cover and precipitation are of interest. To be able to predict the weather with greater precision and over a larger area, it is necessary to access weather satellites. The Weather Satellite Receiver with its QFH antenna works with special software installed on your PC to form an ideal weather monitoring station. You can use it to receive data from the NOAA series of orbiting satellites. Three satellites are currently active: NOAA12, 15 and 17. In early 2005, NOAA18 will be launched into orbit. With the latest technology, it is now possible to access weather images for private use which were previously reserved exclusively for professional applications. After you install the software supplied on the enclosed CD on your computer, you will find all of the necessary programs and descriptions in the WEATHERMAN directory. This description provides an overview of WEATHERMAN’s components and setup. A description of the software can be found on the enclosed CD.

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2.1 Delivery scope for WEATHERMAN

• Weather satellite receiver for 137 MHz • QFH antenna with approx. 15 m coaxial cable • Installation instructions • 230 V AC / 9 V DC power supply • Audio cable with 3.5 mm connector • CD with documentation and software

2.2 Prerequisites

PC or laptop with a Pentium processor >= 166 MHz, sound card and Windows XX, 2000, XP, ME

2.3 Requirements for the Weather Satellite Receiver

The receiver is designed to receive data from weather satellites in the 137 MHz band. The device has a very high input sensitivity so that you do not need a preamplifier for the antenna. The receiver has a bandwidth of 30 kHz and an automatic frequency correction (AFC) circuit to compensate for the frequency offset of the satellites as they orbit. The transmit frequency is subject to Doppler shift due to the relatively high speed of the satellites (approx. 7.8 km/s). When the satellite appears and approaches our current location, the frequency will be about 3 kHz higher (or about 3 kHz lower in the opposite case). This is why the automatic frequency correction (AFC) circuit is an absolute must for the receiver.

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2.4 Special requirements for the weather satellite antenna

Since the satellite signals come from all directions, we need an antenna that will pick up signals from all around. Here, “all around" means the entire hemisphere of the sky (with respect to our current location). Conventional antennas with their directional characteristics tend to be very poor for receiving satellites in polar orbits. Satellites in polar orbits transmit radio waves with circular polarization. The receiving antenna must have the same polarization. A distant satellite situated over the Mediterranean, Spain or Scandinavia (with respect to Germany) will have a relatively flat angle of incidence and will be received primarily with linear polarization. As the satellite gets closer, the elevation angle will increase and the polarization will become increasing circular. A quadrifilar helix (QFH) antenna is well suited to receiving such signals.

Receive characteristic, QFH antenna

QFH antenna

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3. Connectors and operating elements

3.1 DC 9 V jack

Connect the 9 V power supply which is provided to the “9 V DC” jack. Only use the power supply which is provided to power the device. Plug the cable from the power supply into the jack labeled “9 V DC”. WARNING:

The receiver is protected against improper polarity, but the device will not be operational if the plus and minus terminals are reversed.

The Weather Satellite Receiver for 137 MHz does not have an ON/OFF switch. As soon as the device has power, it will be ready to operate. After it is powered on, the green “Power” LED will light up on the front panel and “NOAA Scan Mode” will appear in the LED display. The red “Satellite active” LED will light up if a weather satellite is received. Using a V.24 (RS232) interface cable (not included) and the “PC V.24” connector, you can control the Weather Satellite Receiver from your PC using the Wettersat.exe program. “NOAA Scan Mode” or the NOAA frequency will appear in the “Receiver status” LCD display. The software can be found on the enclosed CD.

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3.2 Antenna input / Signal / Headphones

Connect the QFH antenna to the BNC jack labeled “Antenna input 50 Ω”.

3.3 Signal jack

Connect the “Signal” jack to the supplied audio cable and the soundcard microphone input (or line input). 3.4 Headphones jack

The jack with the „“ icon is provided for connecting headphones for audio monitoring. If the settings that are available for the level (bargraph in the Wave Trace program) under “Recording Control” on the “Signal” jack

are not sufficient, you can connect the headphones jack „“ icon to the microphone input (or line input). Use a screwdriver to set the basic level (volume) for the headphones jack at the “Volume ” icon.

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4. Displays and LEDs

4.1 Power LED

The green LED labeled “Power” indicates that the Weather Satellite Receiver is powered on.

4.2 Satellite active LED

The red “Satellite active” LED will light up if a weather satellite is received.

4.3 Receiver status LCD

The LCD displays the receive frequency in MHz, the receive field strength in dBm and the current status of the receiver. Receive frequency: 137.1 MHz to 137.91 MHz Receive field strength: -120 dBm to -90 dBm in steps of 2 dBm Receive status: NOAA Scan Mode; NOAA frequency or NOAA active

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4.4 Volume

Use a screwdriver to set the volume for the headphones jack at the

“Volume ” icon.

4.5 NOAA Weathersat Software

The software allows you to control the Weather Satellite Receiver via the V.24 (RS232) interface. Connect the V.24 interface on the Weather Satellite Receiver to your PC using a V.24 cable. Once they are connected, run the “Wettersat.exe” program.

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The “Receiver” field will appear in green as soon as the link between the PC and Weather Satellite Receiver is activated. If it doesn’t work, you need to set the proper “COM” port. Use the NOAA+ and NOAA- buttons to set the Weather Satellite Receiver to the different receive frequencies. In “NOAA Scan Mode”, the frequencies used by the Weather Satellite Receiver are automatically scanned in sequence and displayed on the PC. When a frequency is detected, the “NOAA” field will turn green and the proper frequency will be displayed. The satellite’s field strength will appear in the “Status / Field strength” field. For usable receive signals, the display range varies between approx. -115 dBm and -95 dBm in steps of 2 dBm.

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Setup of the Weather Satellite Receiver including the satellite antennas and PC

External power supply (230V AC / 9V DC)

PC with soundcard and software

Audio cable between “Signal” receiver output and PC soundcard

Received weather image

Control of the Wetter Satellite Receiver via V.24 is not absolutely necessary.

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5. Specifications

Weather Satellite Receiver Antenna input 50 Ohm/0.30 µV for supplied QFH antenna

Headphones jack: Headphone impedance ≥ 32 Ω Adjustable output level adjustable [approx. 100 mVss to 4 Vss into 1 MΩ

Audio interface: Signal

3.5mm jack [approx. 100 mVss into 1 MΩ for the supplied audio cable link to the PC

Connector: PC V.24 (RS232) V.24 jack for control of the Weather Satellite Receiver via a PC or notebook

Power supply: 9 V DC External power supply (230V AC / 9V DC)

Power consumption: Approx. 100 mA via the 9 V DC input Dimensions: 85 x 160 x 40 mm (width x depth x height) Weight: Approx. 220 g Article number: 70351.001

Software for Weather Satellite Reception

Description Version 1.1

VIERLING Communications GmbH

70351.203/20 - 1.1 – 20050318

VIERLING

Page 2 70351.203/20 - Software for Weather Satellite Reception 1.1

VIERLING Communications GmbH Pretzfelder Straße 21, D-91320 Ebermannstadt Postfach 11 65, D-91316 Ebermannstadt Tel.: +49(0)9194 767175 Fax: +49(0)9194 767179 E-Mail: [email protected] Internet: http://www.vierling.de © 2005 VIERLING Communications GmbH, Ebermannstadt All rights reserved. Any reproduction, further processing or dissemination of this document or its contents, whether in whole or in part, by any means is expressly prohibited without the prior written consent of VIERLING Communications GmbH. We reserve the right to make changes without prior notice. Please note that great care was exercised in the preparation of this text. However, VIERLING Communications GmbH does not accept any liability for any errors that might be present in the text.

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Software for Weather Satellite Reception 1.1 - 70351.203/20 Page 3

Contents

1. General information .........................................................................5

2. “WXtrack” orbit computation program ..........................................6

3. “WaveTrace” program ...................................................................12 3.1. “SatSignal” decoding program.....................................................17 3.2. Image recording technique............................................................19

4. Troubleshooting .............................................................................24 4.1. Basic information about satellite orbits and reception of

weather satellites ...........................................................................24 4.2. Operating problems and how to fix them ....................................25

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1. General information

WEATHERMAN consists of the Weather Satellite Receiver, antenna and the software described here. When combined with your PC, it forms an ideal weather monitoring station. You can receive data from the NOAA series of satellites orbiting at 820 km, decode the data and display the weather images. Discover the world through the “eyes of the satellites”. The software provided on the CD consists of three programs: WXtrack is an orbit computation program that allows you to compute, display and predict the flyover times and orbits for your current location. WaveTrace is used to automatically record and save the tone signals transmitted by the satellites with time-stamps. SatSignal is a decoding program that decodes the received analog tone signals from the weather satellites and displays them as weather images in different spectral ranges on your PC.

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2. “WXtrack” orbit computation program

The WXtrack orbit computation program displays the world map with the current receiving site along with selected satellite orbits as a function of the current time of day and the monitoring location. In the example here, NOAA17 flew over Germany at 10:32 UTC. It is necessary to select and set the displays for satellite orbits and the site in the “Options” window (top left). Since the program can be used globally, you will need to make some settings in the “Setup” tab (see top left in figure). Please confirm the messages that appear when you first run the program after installation with “OK” or “Ignore”. In the “My location details” area at the bottom right, set the position of the receiving or monitoring site.

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Use the “Cities” panel to select the country and city. To enter an exact location, you can click on the “Edit” button to enter latitude and longitude data for your current site.

To determine the flyover times for the weather satellites, it is sufficient to just enter the nearest city to your current location as shown in the table. You can select the satellites displayed in the “Choose active satellites with drag and drop” area at the top left and drag them into the active window. Three satellites are currently active: NOAA12, 15 and 17. In early 2005, NOAA18 will be launched into orbit. You can also find the international space station under ISS (ZARYA). In the “Pass list generator” area at the top right, the current flyover times are displayed for the selected satellites for the receiving area.

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Use the buttons in the “Choose file paths” area at the bottom left to set the path in which the program WXtrack is installed on the hard disk with its files and satellite data. The time of day for the WXtrack program comes from the PC system clock. The program always displays the time of day using UTC (Greenwich Mean Time, GMT). It is necessary to use the appropriate factor for the receiving location to adjust the UTC time (for Germany +1h or +2h during daylight savings time in the summer).

We recommend the following basic settings in the Options menu. - Map Projection Cylindrical - Update rate 20sec

- Show Footprint Selected - Show Pass box Weather satellites – all map

projections - Show Show scanner line - Show Ground Track 1 orbit back, 3 orbits forward - Show Radio horizon - Show My location Broken cross - Show Night time shading Strong - Show Sun or Moon Sun

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The WXtrack program has many more display options which will not be covered in great detail here.

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The orbital parameters for the satellites must be updated from time to time (monthly). This is important particularly when monitoring the ISS. You can perform a download via the Internet in the “Options” menu under “Update Keplers...”. You can check and query the age of the orbital parameters in the “View” menu under “Satellite orbit data...”.

You can also use the Kepler Manager program to download the Kepler data from the Internet. To download data from the Internet, we recommend that you register with the Space Track Homepage at http://www.space-track.org. Registration is free of charge. Within one or two days, you will receive a temporary

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password and additional instructions. You will have to change your password the first time you log in. It has to have eight characters and can be composed of upper- and lowercase characters. Once you log in with your personal password, you can download Kepler data.

Connecting to Space-Track Logging into Space-Track Logged into Space-Track Saved: Amateur.txt 50 satellites Saved: Geo.txt 635 satellites, 563 unique names Saved: Navigation.txt 112 satellites Saved: Weather.txt 51 satellites Saved: Visible.txt 218 satellites, 105 unique namesLogged out of Space-Track

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3. “WaveTrace” program

The WaveTrace program allows you to automatically record and save with a time-stamp the received tone signals which are transmitted by the weather satellites.

In this example here, the recording was made with the name NOAA on January 12, 2005 at 08:49:19 in the directory C:\ NOAA\. For automatic recording, the following parameters must be set in the “Options” field for recording tone signals:

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A “destination directory” of your choice. (e.g. C:\NOAA ) “Resolution” of 8 bits with a “Sampling rate” of 11025 Hz.

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Set the Trigger as shown in this figure.

The tone parameters are configured as shown in the figure. For details about the effects of the individual parameters, see the file Wavetrace.doc or under “Help". The parameter “Max. size (total)/MB” is set to 60 MB which corresponds to data for nine flyovers (half a day).

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Now activate the program by clicking on “Start”. Recording will begin as soon as a weather satellite tone signal is detected. The data are saved on the PC’s hard disk.

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Activate the “Volume Control” for the soundcard with the “Option” button under “Properties Recording” in the “Recording Control” area for the proper input (Microphone) which is connected to the Weather Satellite Receiver In the example, we are using the Microphone input.

The bargraph in the Level/dB field (WaveTrace program) should be in a range of about -8 dB to -10 dB without the tone signal (receiver noise, no signal). This is set with the volume control under “Recording Control”. Check the exact setting after the first recordings are made using “Wave signal level...” in the “VIEW” menu in the SatSignal program (see also page 22) and adjust it with the volume control under “Recording Control”.

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3.1. “SatSignal” decoding program

The SatSignal program is used to decode the data recorded by the WaveTrace program and display the data as a weather image in visible Channel A and near infrared range Channel B. The False color image represents the combination of Channels A + B.

Using the WaveTrace program’s recording directory, the desired file is read with “File open” (see figure top left) or “Open” (see figure bottom left) into the SatSignal program and decoded. We recommend the following settings in the “Options” (see figure top left) for your initial use of the software.

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Input Filter - normal Geostationary - Assume none Satellite type - Auto Sync sensitivity boost - Normal Attempt re-sync - Activated Gamma correct - weak NOAA color model - HLS NOAA illumination adjust - none In the “Settings Sampling Frequency” menu, set a value of 11025 (nominal). Select the satellite flyover direction in the figure at the bottom left Direction towards “South” or “North”.

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Click on the Process button to start the decoding process. The image that was decoded can be displayed in the visible range (Channel A), the near infrared range (Channel B) or as a false color image (False color). Warmer areas are colored in red and colder areas are colored in blue. The intensity of the coloring indicates the temperature (dark blue = very cold, dark red = very warm). The program has some other display options that can be found under “NOAA color model”. Display of rain clouds and the thermal weather image can be activated with “Therm” or “CloudTop”.

3.2. Image recording technique

The recordings have as their starting point the sound files saved on the hard disk in wave format based on the data received by the weather satellite receiver. Generation of a False Color recording requires an IR channel (Channel B) and the VIS channel (Channel A). The recording is transferred in APT format. (Automated Picture Transmission) The two channels are transmitted with reduced resolution of 4 km/pixel by the NOAA satellites. The bars on the right and left edges of the image are markers. A 11.3 ms long marker represents the radiation from space for the selected spectral range. The alternating black and white bars are minute markers. On the other edge of the screen are fields with a height of 8 rows each with different brightness levels. This represents telemetry data, the modulation index and blackbody temperature for the different sensors.

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If these fields are on the right side of the image, the satellite is traveling from north to south. If the satellite is traveling from south to north, the fields will be on the left side of the image. The change in the flyover direction results from the superposition of the satellite’s orbital plane and the earth’s rotation. Two rows are transmitted per second. The analog signal (APT row) is modulated onto an FM carrier at 2400 Hz using amplitude modulation. Continuous transmission takes place via the corresponding VHF link (137.50 MHz or 137.62 MHz). The transmit frequency is subject to Doppler shift due to the relatively high speed of the satellites (approx. 7.8 km/s). When the satellite appears, the frequency will be about 3 kHz higher (or about 3 kHz lower in the opposite case). AFC circuitry in the receiver is used to compensate for this frequency shift. A weather image we received looks like this: Large parts of Europe are under cloud cover and a low-pressure system is forming over Iceland.

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Lake Constance is covered by rain clouds. Mallorca is hidden under cloud cover.

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To check for proper settings in the “Recording Control” area, use the SatSignal program’s “View” > “Wave signal level...” menu (after the *.wav file has been decoded). Set the level so that the “blue line NOAA” is not exceeded substantially to the right. In this example, the drive level is properly set with the corresponding volume controller under “Recording Control”. If the range is exceeded, reduce the recording level.

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The WXtrack and SatSignal programs can be downloaded on the Internet at http://www.satsignal.net. We recommend professional registration which is available for the SatSignal program for about 60 Euros. It offers a number of additional features. After you register the software, for example, you will have access to international borders, distance measurements, temperature displays and coordinates.

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4. Troubleshooting

4.1. Basic information about satellite orbits and reception of weather satellites

Receiving weather satellites is not quite as simple as receiving radio or television programs. There are currently three satellites which can be picked up regularly: NOAA12, NOAA15, NOAA17 and (starting in May 2005) NOAA18. You can only receive orbiting satellites when they pass over your location. You will not receive every flyover. You can only receive those with the highest elevation (elevation angle over the horizon) for your location.

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As a general rule, there are three flyovers in the morning, afternoon and evening (see figure). The orbits of the NOAA satellites pass close to the north or south pole and the flyovers are approximately in a north-south direction (or vice versa). The small deviation from an exact polar orbit is intentional. The anisotropic gravitation resulting from the earth’s asymmetry leads to a turning of the orbital plane in space. The deviation from a north-south direction of travel has been chosen so that the orbit turns about the earth's axis once per year. This keeps the satellites approximately in sync with the sun so they can be expected at about the same time every day. For the three currently active satellites, there are nine flyovers in the first half of the day and an additional nine flyovers in the second half of the day. Per flyover, between 4 MB and 9 MB of data are saved on the hard disk. This produces an average data quantity of approx. 120 MB per day. Flyovers which occur very far to the east or west of the location will be very flat on the horizon and are thus difficult or impossible to pick up.

4.2. Operating problems and how to fix them

Check the following items if the weather satellite receiver is not working properly:

• Are all of the connections properly plugged in? • Does the Weather Satellite Receiver have power? • Is the QFH antenna connected? • Is there a satellite within range of my location? • Have I taken into account the time change (daylight savings time)

with respect to UTC? • Is my PC’s clock set properly? • Are the programs WXtrack, SatSignal and WaveTrace properly

installed on the PC? • Have the Kepler data been updated in the WXtrack program? (not

older than 3 months) • Is it possible to adjust the level displayed in the WaveTrace window

with the record slider? • Is the soundcard installed?

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Do not open the Weather Satellite Receiver under any circumstances! The following table lists possible problems and how to correct them.

Problem Possible cause Action

Power LED does not light up.

Power supply not connected.

Connect the power supply properly.

No sound audible in PC loudspeaker.

Audio cable not connected between PC and Weather Satellite Receiver.

Check whether the audio cable is plugged into the microphone or line input.

Can’t pick up any weather satellites.

QFH antenna not connected.

Connect the antenna cable to the BNC jack on the receiver.

Is there a satellite within range of my location?

Did you take into account the time change (daylight savings time) with respect to UTC?

Wait for the next flyover.

The satellite position shown on the PC is not the correct position.

No adjustment has been made for daylight savings time, standard time or the time zone.

Adjust the PC clock in the Control Panel under Date/Time.

The WaveTrace level display does not respond.

Volume control has not been set up or the wrong recording channel was activated.

Check whether you activated the proper recording channel (microphone or line) under Recording Control.

WaveTrace 2005-04-12 Page 1

Brief description of the "Wave Trace" software module

Overview The software module allows you to record an analog signal in the voice band (200 Hz to 5,000 Hz) as a trace file in wave format (*.wav). Recording can be set to start and stop using trigger settings for the Level range or Frequency range. The trigger condition can be set in the level range between -100 dB and +3 dB. For the frequency range, the trigger condition can be set between 100 Hz and 3,900 Hz. Recording can use a sampling rate of 8,000 Hz or 11,025 Hz (Sampling) and a resolution of 8 bit or 16 bits. The trace file is saved in a user-specified directory with a time-stamp. A bargraph shows the current level conditions.

Fig. 1

Example: Fig. 1 shows a recorded trace file with a time-stamp. The time-stamp indicates when recording began. The bargraph shows the level is approx. -23 dB.


Operation Press the Start/Stop button to activate the Wave Trace software module (session start). As soon as a trigger event occurs that corresponds to the settings, recording will begin. It will end as soon as the trigger condition is no longer valid. The software module will remain active and will record further trace files if new trigger events occur. Press the Start/Stop button again to halt the Wave Trace software module (session end). Click on the Exit button to exit the program. Click on the Options button to set the properties of the wave files that will be generated and the trigger conditions. You can control the input level using the Windows Mixer (see the next sections for more details). Input level You can set the input level (volume) using the mixer function (volume control) provided by Windows. Access the level with Start > Programs > Accessories > Entertainment > Volume Control (this might be slightly different depending on your version of Windows); Once you are in the Windows Mixer: Option > Properties Set "Adjust volume for" to Recording. You can now adjust the input level with the slider for the input used for recording (Fig. 2).

Fig. 2


Options: Wave Fig. 3 shows the possible settings for the wave file (trace file).

Fig. 3 File prefix: The file name is formed from this prefix plus the time-stamp (see also

Fig. 1). Dest. directory: Directory in which the trace file will be saved. Resolution: Resolution of the trace file Sampling rate: Sampling rate for analog/digital conversion


Options: Trigger Recording (start/stop) can be triggered based on the "Level" or the "Frequency". When triggering on the level, a signal whose total level is above the set threshold is used as a trigger. When triggering on the frequency (single tone), a tone within the signal is evaluated which has a certain frequency within a specific tolerance and exceeds the set minimum level. If both trigger types are selected, triggering occurs if at least one of the trigger conditions is fulfilled. If no trigger type is selected, then no triggering or recording is possible. Fig. 4 shows the settings used to trigger based on the level.

Fig. 4 Recording prior to Trigger On/sec: The signal that was saved in the buffer memory prior to

the occurrence of the trigger condition for the time duration set here is added to the front end of the recording.

Recording after Trigger Off/sec: Recording does not end until the trigger condition has gone unfulfilled for the time duration set here.

Maximum file size (single): Recording ends when a trace file reaches this size limit. No further recording will occur in this session.

Maximum file size (total): Recording (and the session) will end when the trace files in the current session together reach this size limit.

Level/dB: Trigger level; if the total signal reaches or exceeds this level, the trigger condition is fulfilled. Values between -100 and +3.


Figs. 5 and 6 show the settings for triggering based on the frequency (single tone).

Fig. 5 The button to the right of Frequency (single tone) will lead you to the tone parameters on which the trigger behavior is based.

Fig. 6 Wave Trace searches in the specified band (frequency ± tolerance) for the strongest tone, measures its frequency and power (only for this tone and not for the band) and compares these values with the settings under Minimum level and SNR. Frequency/Hz : A signal at this frequency acts as a trigger. Values between 100 Hz and

3,900 Hz. Tolerance/Hz : Maximum deviation from the frequency for which the signal will still act

as a trigger. Values between 0 Hz and 2,000 Hz. Minimum level/dB: Minimum level at which triggering will occur. Values between -100 dB

and +3 dB. SNR/dB: Minimum signal-to-noise ratio (SNR) for which triggering will still occur.

Values between -50 dB and 50 dB.

weather satellite receiver

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