FREQUENTLY ASKED QUESTIONS PREDICTOR version 9.1

Transcription

1 FREQUENTLY ASKED QUESTIONS PREDICTOR version 9.1 Frequently Asked Questions Predictor

2 CONTENTS INSTALLATION...3 PREDICTOR PROJECTS...4 CALCULATION...5 IMPORT/EXPORT...8 DATA ENTRY AND ITEMS ISO/DAL RMR LimA-CRTN/XPS/ISO ACOUSTIC DETERMINATOR Frequently Asked Questions Predictor

3 INSTALLATION Q: Can Predictor be used within a multi-user Citrix or Windows server environment using remote sessions? A: Predictor does not offer multi-user access for the dongle. The USB dongle therefore cannot be used in a remote desktop session or in a multi user environment like windows server or Citrix. In that case Predictor will switch to modelling mode, meaning that you can enter data but cannot calculate. Q: What are the recommended system requirements for Predictor? A: Microsoft Windows bit Windows is recommended as it improves stability, memory management and performance At least 1 GB of free disk space, plus disk space used as a working area For calculation of large Advanced models, tiling is recommended in combination with Calculation Client add-ons and/or the multi-core option for multi-processor computers Q: Which access rights are necessary for using Predictor? A: In the program folder you need at least read rights. In the data folder you need all rights. Also you need write rights in the application data folder. Q: Will existing projects be overwritten by the Predictor setup program? A: No, only the program software itself will be overwritten. No projects will be changed and can be used in the new version of the software. Q: How can I set the number of cores to be used for the calculation A: Predictor Plus 7810A with 4 core support (BZ-5703) can use the full power of a Quad Core PC for calculations. However, sometimes it is convenient to work on other tasks while Predictor calculates in the background. In those cases the number of cores can be set lower. To set the number of cores that Predictor uses: 1. Go to your application data folder (in XP this is C:\Documents and Settings\USER\Application Data\Predictor) and open the PREDICTOR.INI file 2. In the [Preferences] section, insert NRCORES=X where X is the maximum number of cores you want Predictor to use 3. Start Predictor To use all the cores, delete this line in the PREDICTOR.INI file or set the variable X to a higher number Q: Predictor starts in Demo mode even though I have installed the correct license files. A: This could be a known Windows 7/Vista problem. These windows versions maintain a virtual store with copies of program files. The solution is to empty the virtual store. The virtual store for Predictor 9 is located at C:\Users\<loginname>\AppData\Local\VirtualStore\Program Files (x86)\bruel and Kjaer\ENV\Predictor V9.10. Frequently Asked Questions Predictor

4 PREDICTOR PROJECTS Q: How can I zip my project and/or make a backup of my project(s)? A: To back up your project, you should make a copy of the entire project folder including all sub-folders. You can use the menu option File Zip Project. After zipping the project, the file PROJ_DATE.ZIP will be present in the project folder. This is the zipped project. So instead of making a copy of the complete project folder, in this case you only need to copy the PROJ_DATE.ZIP file. Note: Predictor does not have an unzip option. For this purpose you should use a program like WinZip. Q: How can I make a copy of a Predictor project? A: Use the explorer and make a copy of the project folder including all sub-folders. Note: Because of Predictor s automated bookkeeping system it is not recommended to work on copies of projects. To exchange models use the File Export Predictor project menu option Q: Can I modify the project description? A: Yes. Use the button Info from the Open Project dialogue. Then use the [Edit] button to modify the project name. Q: How do I maintain my data? A: Naturally, like all software, you should always make regular backup copies of your software and your data. In networks, your System Administrator usually does this automatically. If you are working on a stand-alone PC, then take copies of your hard disk on disks or tape regularly (for example, once a week). Frequently Asked Questions Predictor

5 CALCULATION Q: What is the maximum size of a Predictor project? A: There are only a few exact limits. The main restriction will be the performance. Predictor can easily handle models with thousands of items on any PC. For larger models you will need a more powerful computer. Predictor does not apply a restriction when entering items. However for a calculation a restriction is used based on the Predictor configuration used. Predictor Types 7810-G/I configurations allow calculations of up to emittors, obstacle+terrain edges and obstacle edges. Predictor Types 7810-A/C/D/E/F/H allows calculations of up to emittors, obstacle+terrain edges and obstacle edges. Predictor Advanced Type 7810 B allows calculations up to emittors, obstacle+terrain edges and obstacle edges in 1 model. Larger models can be calculated using the tiling option. In the above definition an emitter is 1 point source during calculation. This means that 1 line source could be several point sources. Q: What effect does a height line and/or a height point have on the calculation? A: Height lines and height points are used to build a 3-dimensional ground or terrain model. This terrain model is used to calculate the local terrain level height for all items that have a relative or absolute height definition. Also the height lines are used as barriers, only if the height line blocks the line of sight. It is then assumed that there are no left and right detours. Note: Height points do not act as barriers. Q: How can I speed up my calculation? A: You can speed up the calculation by taking the following steps: 1. If you have a multiple core computer with more than 2 cores you can use the 4 core support or 8 core support options. These options are available for Predictor-LimA Plus 7810 A, Predictor-LimA Advanced 7810 B and the calculation clients (order numbers BZ 5703, BZ 5704 and BZ-5890, respectively). 2. Use calculation clients to increase calculation capacity. This function is available for Predictor-LimA Advanced 7810 B and is most effective for larger models as there is an operational overhead when using calculation clients. Calculation Clients are available in packs of 2 additional licenses order Predictor Advanced Calculation Client License Pack for 7810 B (BZ 5552). 3. Set a fetching radius at the calculation parameters. For large models, this will omit sourcereceiver combinations with longer propagation distances. 4. Do not calculate reflections. This will give you less accurate results, however it can be useful in some situations to get a quick global result. 5. Simplify your model. Unnecessary model details slow down the model. Simplification can be done with the option Simplify geometry in the mouse menu. 6. Only store group or total results. Do not store source results. This will not only speed up your calculation but will also result in smaller project files. Q: How can I calculate my model with another calculation method? A: Make a new model for the other calculation method. Copy and paste all items from the original model into the new model. Most item types can be copied from one calculation Frequently Asked Questions Predictor

6 method to another. However, some item types, mostly sources, are restricted to one calculation method only, for example, CRTN-roads cannot be copied into a RMR-rail model. Q: Although I am able to get the model to run with point receivers, the grid option is greyed out, so I am not able to compute contours. A: Going into display settings and checking display grid and grid point will probably solve the problem. You should then be able to enter a grid and compute the contours. Q: I have calculated the model but do not see results. A: This can happen when there are no receivers in the main group and you have selected storage of total results. In that case, only the results of the main group are stored and because there are no receivers in the main group you do not see any results. In that case, use storage of group results or storage of source results. Q: Predictor does not permit me to calculate. A: This could have several causes: Receivers do not have a height There are no receivers and/or no sources in the model Predictor is in modelling mode and there is no calculation client installed on a PC in the network. This is the case if a valid license file is present but the USB dongle is not present on the PC. In modelling mode you should be able to use the Server calculation only when you installed a calculation client on a dedicated PC in the network. The USB protection key should then be present on the dedicated PC. Predictor is in demo mode. This is the case when there is no valid license file present Q: I get the message too many Obstacles in file: HGT.BNA. How can I solve this? A: The message 'too many Obstacles in file: HGT.BNA' is generated when there are too many obstacles in the model. The file HGT.BNA contains the height lines. The maximum number of nodes of all height lines is 1 million nodes. Most likely the model has more than 1 million nodes. There are 3 solutions: 1. Simplify the model using 'Edit Change Items Simplify Geometry'. 2. Simplify the model using 'LimA-link Simplify polylines' 3. Use the 'Edit Tile model' option and split the model into several models. With option 3 you can split the model in several smaller models. With the batch calculation of predictor you can calculate all models in 1 run by using the option Calculation Batch calculation. When the calculation is done you can batch export all results of all models into 1 shape file. This shape file can then be read into Predictor Analyst for a total contour and the calculation of noise exposed people/dwellings. Q: I get the error message Out of Memory when starting a calculation or when using the Calculation terrain model option. How do I solve this? Frequently Asked Questions Predictor

7 A: Most likely the terrain model is larger than the Windows 32 bit limit of 2 Gb for files. When the number of nodes for all height lines is much larger than the specified limit of nodes this can happen. The limit for the terrain model calculation is around 4 million nodes. There are 3 solutions: 1. Simplify the model using 'Edit Change Items Simplify Geometry'. 2. Simplify the model using 'LimA-link Simplify polylines' 3. Use the 'Edit Tile model' option and split the model into several models. With option 3 you can split the model in several smaller models. With the batch calculation of predictor you can calculate all models in 1 run by using the option Calculation Batch calculation. When the calculation is done you can batch export all results of all models into 1 shape file. This shape file can then be read into Predictor Analyst for a total contour and the calculation of noise exposed people/dwellings. Frequently Asked Questions Predictor

8 IMPORT/EXPORT Q: How do I calibrate the local coordinate system of my Predictor model with respect to the GPS coordinate system for exporting to Google Earth A: A Predictor model uses an orthogonal coordinate system in meters with a 2 decimal accuracy. This coordinate system can be based on your national orthogonal coordinate system as long as the x and y coordinates are between ,00 and ,00. When exporting the model to Google Earth and/or when importing measured noise levels from a B&K 2260 sound level meter it is important to calibrate the model with respect to GPS coordinates. This can be done by entering at least 2 GPS calibration point items in the model. The location of each GPS calibration point both in local x/y coordinates and in latitude/longitude coordinates must be exactly known to the user. After the GPS calibration points have been entered in the model Predictor will automatically convert the local x/y coordinates into GPS coordinates when exporting to Google Earth. Also the GPS coordinates of a measurement taken with the B&K 2260 SLM will be automatically converted to the local x/y coordinates when importing a receiver with control value from the Q: Can I import landscapes from MOSS? A: MOSS can export in DXF format. See Predictor s help file for more information on importing DXF files. Q: What are the restrictions for a DXF/DWG file to be used in Predictor? A: In Predictor data from a CAD file (supported are DXF and DWG) can be imported as an item. A CAD file is a file which contains coordinates with attributes of several entities and block entities. Entities up to and including AutoCAD version 2008 are supported. Some considerations: The basic geometry of an Predictor item is 2 dimensional (either point, (poly)line or surfaces). Some items do not have a height attribute (e.g. ground region item, address point item). Some items only have 1 height (e.g. building item, point source item). In the case of polyline items this may also be a height value per node (e.g. barrier item, road item). Predictor does not support fully defined 3D volumes. When importing a CAD file the geometry will therefore be modified/converted to fit the item geometry. In some cases, like circles and ellipses, the geometry will be changed into a segmented polyline. If an object in the CAD file is defined by multiple entities these will not be automatically joined during the import. The user will have to do this manually afterwards. Q: Can I transfer a model to another user? A: Yes. There is an export function in Predictor under the File menu. If you already have the project of the other user, then simply use this function to export precisely the models you want to transfer from your project to the other project. You can export one model at a time. For more models, repeat the export action. If you do not have the project of the other user, then make a new project and export the models to this project. Please note that the export function is not meant for backup purposes. Q: Can I copy Predictor information to Word or Excel? Frequently Asked Questions Predictor

9 A: Yes, all information shown in tables, such as the table of results or the list of item attributes, can easily be copied into Word or Excel by using CTRL-A and CTRL-C in the Predictor table and CTRL-V in Word or Excel. With the menu option View View to Clipboard in the 2D view and the button copy the model to the clipboard in the 3D-view the model can be copied to the clipboard and with CTRL-V pasted in Word or Excel. Q: How do I import GPS data from the B&K 2260 A: For many sound measurements, it is essential to document the precise measurement location. For this purpose, 2260 Investigator/Observer can input GPS data and save it with the measurement data. This note takes you step by step through the process, to supplement the brief introduction in the user manuals. GPS Support Using the serial interface on Type 2260, the following modules support input of GPS information: BZ-7201 (> Ver. 3.0) BZ-7202 (> Ver. 2.0) BZ-7205 BZ-7206 BZ-7208 BZ-7210 BZ-7219 Getting GPS data into Type 2260 Type 2260 will accept data from a variety of GPS receivers that support the NMEA 0183 version 2.20 standard for data communication. The data cable from the GPS receiver has to be connected to the serial port on Type Make sure that the baud rate selected in the GPS receiver matches the settings in Type 2260 (Set-up, PC Communication). The GPS receiver should be set up to continuously send GPS information related to its current position. If GPS position information is received correctly in Type 2260, the "System, Clock" display will show GPS Information (see photos below). The display is not continuously updated but will read GPS data when the softkey "Update GPS Info" is pressed. In this way the user can concentrate on getting the correct GPS coordinate stored in Type 2260 before making the noise measurement(s). Please note that as long as GPS data is displayed in Type 2260, this information will be attached to all subsequent measurements. This means that you don't need to acquire a new GPS coordinate when doing Frequently Asked Questions Predictor

10 several measurements in the same position. To continue to store measurements without GPS information, press "Clear GPS Info". Remember that the On-line Help in Type 2260 (press "?" when in "System, Clock" display) will describe this functionality. Note: The GPS information in the 2260 display is lost when you switch off the instrument. Attaching GPS data To attach a GPS position to a measurement, perform the following steps: 1. Position the GPS receiver in the desired location. 2. Press "Update GPS Info" in the "System, Clock" display. 3. Perform the noise measurement(s). 4. Move to a new position, put the GPS receiver in place and press "Update GPS Info". Alternatively, press "Clear GPS Info". Seeing GPS data in your PC To transfer GPS information from measurements to the Type 7815, 7820 or 7825 PC software, right-click on a measurement and select "Properties". The information is then available under "General Information Location" (see screen shots below). Note that this field can be scrolled to see the following information: GPS Information Time: :19:24 Latitude: 5549'03,2'' N Longitude: 1232'00,3'' E Altitude: 13.3 m Precision: 3.4 m GPS Information can also be imported into 7810 Predictor and 7812 LIMA. Below you see GPS information imported into 7810 Predictor. If the model is calibrated with respect to GPS, the measurement will be inserted at the correct position. Frequently Asked Questions Predictor

11 Frequently Asked Questions Predictor

12 DATA ENTRY AND ITEMS Q: How can I copy items to another project? A: Copy the items, open the other project, open the model and paste the items in the model. Q: How does Predictor know that items are copies of each other? A: On creation of an item Predictor will give the item a unique identification number called Item database ID. When the item is copied to another model this number, however, will stay the same and cannot be modified by the user. Therefore if two models contain items with the same id-number, Predictor knows that they are copies. If the item is copied and pasted in the same model Predictor will treat this as a new item and gives the item a new unique idnumber. These id-numbers are used when comparing models with the menu option Model Compare models. Q: Sometimes when I copy an item from one model to another model, there is a strange effect. The item itself is added to the model, but another item disappears. Why is that? A: Each item has an internal number. If a new item is created, this item will get a new and unique internal number. However, if an item is copied to another model, this internal number stays the same and cannot be modified by the user. Therefore, these items are not considered to be new items by Predictor but merely copies of existing items. Predictor uses this number information, or link information, when comparing models. Both in the Table of Comparisons and in the Model Comparison this link information is useful. There are 4 possible copy/paste actions for items. 1. Normal paste from one model to another In this case, the items are always pasted in the active group of the other model with replacement of items that have the same internal number, due to a previous normal paste of the items. 2. Normal paste within the same model In this case, new items with new unique internal numbers are created and pasted in the active group. The new items have the same attributes as the original items except for the coordinates. The new items are placed some pixels down and to the left of the original items. 3. Paste special from one model to another With the With group structure option, you can override the default pasting in the active group. If this option is checked, the group structure of the original items is copied to the new model and the pasted items are put in this group. With the As new item option, you can override the default pasting that replaces older copies of the items. If this option is checked, the pasted items are pasted as new items with new unique internal numbers and therefore have no link to the original items or other older copies. 4. Paste special within the same model With the With group structure option, you can override the default pasting in the active group. If this option is checked the group structure of the original items is copied and the pasted items are put, as new items, in this group. The As new item option is checked and grayed-out because a copy/paste in same model will always create new items. It is not possible for 2 items in the same model to have the same internal number. Frequently Asked Questions Predictor

13 Q: I cannot enter a specific item type - it is greyed out in the menu option. A: The display of this item type has been temporarily disabled in the display settings. Simply select the menu option View Display Settings and enable the display of this item type. Q: I cannot enter group reductions - this option is greyed out. A: Group reductions can only be used for the groups directly underneath the main group. The main group itself cannot have a group reduction. Frequently Asked Questions Predictor

14 ISO/DAL Q: How do I model the effect of indoor noise sources and/or the wall of a building as outdoor sound sources? A: In order to model indoor sources and/or emitting walls or roofs for an ISO/DAL model, simply use an emitting façade and/or an emitting roof. By using the snap option these items can easily be positioned on the façade of a building or on top of it. You can enter the measured sound pressure level inside (about 1 or 2 metres from each surface) and select the insulation material from a catalogue. Predictor will then automatically show the sound power level of the emitting surface. During the calculation also automatically a directivity for a façade or a roof is applied. Q: How do I model rail traffic in the ISO method? A: Briefly, you can use a single line source (from the ISO Industrial method) to model the train. The source needs to be defined in sound power per meter. To get the actual measurements, you can use the following formula: Lw/m = SEL + 10 log(n/3600) + 10 log(r) + 8 where: Lw/m is the sound power per metre of the source; SEL is the measured SEL of a single train passing; N is the number of trains per hour of this type; r is the distance in meters of the SEL measurement. Please note that this formula does not take into account the effects of reflection and diffraction and is valid for the far field. For more detailed models, use sources for separate components of the train such as the wheel/track, the aerodynamic noise from the body, etc. Q: What does the Discard building/industrial site option at the attribute tab-page of the point and line source attribute form mean? A: This option in an ISO/DAL model is for when you want to ignore the screening and reflection affect of a specific building or industrial site for certain sources. The most common use is for industrial sites when the sound power of the complete site is based on measurements around the site. In that case, the sound power will be spread out over several point sources located in the industrial site itself. You will also enter the industrial site as an item because it could screen off other sources outside the industrial site. However, the screening effect of the industrial site is already included in the sound power. In that case, all sources that represent the industrial site can be linked to the industrial site item. Q: What does the Discard reflection in building option at the attribute tab-page of the point and line source attribute form mean? A: This option in an ISO/DAL model is for when you have included the reflection effects of the wall of a building in the sound power level, which you have assigned to the source (this could arise, for example, from an in-situ measurement of an outlet fan mounted on the wall). Linking the source to the building ignores the reflection effects of the building in the model (as they are already taken into consideration). Frequently Asked Questions Predictor

15 RMR Q: How do I model the real height above track height using absorbing barriers in a RMR model? What does this mean? A: A barrier alongside the track (on the railway embankment) should always be modelled as a 100% absorbing barrier, even if it is a (partially) reflecting barrier. That also goes for platforms and other vertical constructions close to the track. This because, in reality, reflections across the track will never occur, since the train obstructs them! On the other side of the track, reflections between the barrier and the train will reduce the screening effect of the barrier. The reduced screening effect of reflecting barriers is accounted for by its (reduced) effective height. For reflecting platforms, U-shaped bridges and M-shaped constructions, carry out an alternate procedure. These constructions usually have a small height relative to the track, and their reduced screening effect is more appropriately modelled by applying a profile correction of 5 db. Q: How is a railway station modelled in practice using the RMR method? For example, if I have regional trains that arrive at the station every 10 minutes in both directions and stop for 1 minute at the platform. A: At railway stations, the minimum speed for trains is 40 km/h. So the trains are modelled as if they would never stop! If we have trains, consisting of 4 units each, that arrive every 10 minutes in both directions, this will be modelled by a flow rate of (60/10)*4 = 24 units per hour in both directions. How long they stop at the platform is irrelevant. Frequently Asked Questions Predictor

16 LimA-CRTN/XPS/ISO Q: What is the effect of bridge items in LimA-CRTN/XPS/ISO models on the screening. A: The screening effect is depending on the calculation method. As the CRTN standard has a more 2D propagation model the screening effect for bridges in LimA-CRTN is limited to roads underneath bridges. As a default this is also the case for LimA-XPS and LimA-ISO. However in LimA-XPS and LimA-ISO the bridge can be declared floating. In those cases the bridge is also considered to be a screening object for sources aside of the bridge item. Q: How can I create raised and hanging barriers in LimA-CRTN/XPS/ISO models. A: A raised barriers can be created by using the relative to item below height definition for the barrier. In that case underneath all nodes of the barrier supporting pillars must be created. These pillars can be very small building items. The height of the barrier could also be negative. In that case the barrier is hanging down from the height of the pillar buildings. Q: How can I create a (cantilever) barrier on a bridge item in LimA-CRTN/XPS/ISO models. A: A barrier on a bridge item can be created by using the relative to item below height definition for the barrier. In that case all nodes of the barrier must be located on the bridge item. In case of a cantilever barrier both the bridge item and the barrier item(s) should have the same Floor Assignment number. Q: How can I create multi-level road constructions in LimA-CRTN/XPS/ISO models. A: Multi-level road constructions can be created with multi-level bridge items. The road items in that case should have an absolute height. You cannot use the height definition relative to item directly below as it is undefined which bridge item is directly below. Modeling barriers on multi-level bridge items also needs special care to make sure underneath each node of a barrier only 1 bridge item is located. In that case you can use the relative to item below height definition. Q: How does Calculate façade effect for building works for receivers and vertical grids in a CRTN model. A: The own façade reflection of 2.5 db(a) is applied only for receivers with the option Calculate façade effect for building checked and when there is a building within 5 meter distance of the receiver. In all other cases there is no own façade reflection. Note: The own façade reflection is not depending on the reflection definition of the building within 5 meter. This is as it is described in the CRTN standard. However the reflection definition does has an effect on the calculation of an opposite façade reflection. Note: An own façade reflection is not calculated for horizontal grid points and contour points. Q: How does source alignment works for roads in a CRTN model. A: The road attributes road width and source alignment are very important. They are used to temporarily modify the location of the road during the calculation, as described in the CRTN calculation method. Frequently Asked Questions Predictor

17 In the case of aggregated roads, the source line should be moved towards the receiver at 3.5 m in from the nearside edge of the road. Setting the alignment on automatic does this. In that case, the road is always moved towards the receiver regardless of whether the receiver is on the left or right side of the road. In the case of separated carriageways (more than 5m), you should model it in 2 source lines. The source alignment in that case should not be set to automatic but to left or right. The CRTN states that both source lines must be moved towards the outer edge of the carriageway (as seen from the middle of both roads). So for a situation in which the 2 roads are located from left to right and are also entered from left to right, the source alignment of the upper road must be set to left and the alignment of the lower road must be set to right. In this case, the width of both roads must be at least 7m. Note: If the width of the road in this case is set lower than 7m, the source line is not moved towards the receiver but further away from the receiver. This is wrong. The width of the road should therefore always be at least 7m. Q: I get strange (very low) results on receivers in front of buildings and close to the road in a CRTN model. A: The source is moved towards the receiver at 3.5 m from the nearest edge of the road. If the width of the road is set wrongly (too large), the source line will end up on the other side of the receiver and inside or behind the building. This will result in a large barrier effect and low results. Q: I get strange results on receivers very close to the road in a CRTN model. A: If the distance from the receiver to the relocated source line is smaller than 4m, the CRTN is not valid anymore. In that case, Predictor will calculate a standard value based on the emission level of the road. Frequently Asked Questions Predictor

18 ACOUSTIC DETERMINATOR Q: How do I convert spectra? A: Acoustic Determinator Type 7816 has functions to convert the A-weighted spectrum to Linear and from 1/3-octave to 1/1-octave. These functions are part of the acoustic spreadsheet window. The frequency weighting conversion is done with a single mouse click on selected spectra: Conversion from 1/3-octave to 1/1-octave is done using the logarithmic addition function. You must group the 1/3-octave bands into 3 rows with the low, mid and high 1/3-octave bands within each octave frequency on line 1, 2 and 3, respectively (see below) and then you can convert the selected spectra with a single mouse click. To get the spectral data into this format, export the measured spectra to Excel for formatting - this can be done from the sound level meter itself or from other ENV PC software (for example, Evaluator Type 7820). Acoustic Determinator Type 7816 accepts Windows clipboard data and the formatted spectra can simply be copied from Excel. Frequently Asked Questions Predictor