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Support / I have been sent a .nmbackup file. How do I restore it?

« Last post by roger on February 14, 2018, 11:58:16 AM »

If you are restoring this to a ‘remote’ database, then you should use the NoiseMap Server Administrator utility which is normally located:
C:\Program Files (x86)\NoiseMap Five\NoiseMap Server Tools\Bin
It is the file called Administrator.exe
[Set up a shortcut on your desktop for future ease of access.]
This will ask you to log into the remote server.
Then select Database backup and Restore in the left-hand menu
The Database Backup and Restore window opens.
Click the Restore tab
Then browse to where you have saved the .nmbackup file
Select the backup in the main window and click Restore.
The file will be restored to the database system and you will be able to open it in NoiseMap.

This utility will not restore to a ‘flat’ database file.
If you wish to restore to a .nmdb ‘flat’ database file, you need to access the nmbackup.exe utility which
is in your NoiseMap install directory, by default this is:
C:\Program Files (x86)\NoiseMap Five\NoiseMap Client\Bin
This is a ‘command line’ utility as this is an ‘unofficial’ feature, although it works fine.
Since the nmbackup.exe utility has rather an obscure set of commands, we have created a small MS-DOS file to run it for you.
I have attached this as NM5Restore.txt. You need to save this for simplicity in your
C:\Program Files (x86)\NoiseMap Five\NoiseMap Client\Bin
directory and rename it as NM5Restore.bat which makes it an MS-DOS executable.
Then start the command line interpreter (Windows Power Shell) and cd (change directory)to the above directory
Eg: type
cd “C:\Program Files (x86)\NoiseMap Five\NoiseMap Client\Bin”
check you are there by typing
dir
which lists the directory contents – you should see that NM5Restore.bat is there.
Type .\NM5Restore.bat at the command line (note you need the .\ at the beginning of the file name to notify that it is in the current directory)
The follow the prompts.
1 = path to where the .nmbackup file is stored
2 = path to where you want the new .nmdb file to be created
3= name of database to be restored from the .nmbackup file (you can try typing all if you don’t know this, as usually there is only one database to restore anyway)

Sorry if this is a bit complicated but you only have to do it the once.
It is possible to convert the other way but we do not recommend this as 'round tripping' can cause loss of precision due to differences in the way that floating point numbers are stored.

Announcements / NoiseMap 5.2.6 released February 2018

« Last post by roger on February 09, 2018, 12:40:33 PM »

A recent major project needs more than the limit of 100 categories and 100 category combinations and in response to client requests, we have now increased these to 500 categories and 500 category combinations.
A number of other small improvements have been made.

Whilst we recommend the use of a 'remote' MySQL database server for huge projects, we are aware that there is an additional cost implication. Many users are satisfied with the 'flat file' system which uses a built-in database server called SQLite. This can handle huge databases too, but it is not intended for use with multiple simultaneous users, including distributed computing, where many computers are doing calculations of different parts of the model at the same time. This is because SQLite may load some index tables into memory and if different computers change the indexes at the same time, the two copies will become different, causing problems. With MySQL, the indexing is all done on the server computer, so the indexes should never get out of sync.

The remote database can have problems with 'latency' i.e. the response time of the network rather than the data rate in bits per second. NoiseMap does not send large amounts of data, but it does require each packet to be acknowledged. If this takes a long time (and here half a second is a very long time) data transmission become sluggish. The local database system shouldn't suffer from this.

To provide more options for users, from the release of NoiseMap 2.5.6 it is possible to convert backups Of MySQL databases (.nmbackup files) to local SQLite databases (.nmdb files) and vice-versa. However, we do not recommend doing regular round trips between the two systems because they store floating-point numbers differently and conversion can lose precision.

Support / TRL/DEFRA Method 1 for obtaining LAeq from LA10 can give incorrect results

« Last post by roger on February 09, 2018, 12:21:26 PM »

We have identified a problem with Method 1 as set out in the TRL document
CONVERTING THE UK TRAFFIC NOISE INDEX LA10,18h TO EU NOISE INDICES FOR NOISE MAPPING EPG 1/2/37 (2002).
Method 1 shows that you convert the L10 of each segment to Leq and then sum the Leqs to get the period Leq. There are two conversion formulae - one for motorways and one for non-motorways. For L10s of around 70 dB, the Leq is about 3 dB below the L10, but as the L10 drops, the difference reduces. For non-motorways, the formula has a constant term of 24.5 dB, which means that no matter how low the L10 gets, the Leq is never less than 24.5 dB.

When developing the formula, TRL did not consider that the effect of segmenting the roads would be to create a lot of low L10 values, which get converted into an Leq which is much too high.

We would like to make it clear that NoiseMap implements the method correctly as described.

As an immediate fix, we recommend that people set all roads to motorways if they are using method 1. This will result in a much smaller over-prediction. In the longer term, we will revise our implementation of method 1 so that it accumulates the noise from all segments into sub-totals for motorway and non-motorway, and then converts these sub-totals to Leq. This is how the revised (2005) method 3 works. When TRL/DEFRA issed a revision to method 3, it is unfortunate that they did not notice that the same problem would affect method 1. We have not looked at method 2 - probably that has a similar issue, but we think that it is rarely ever used.

Announcements / NoiseMap 5.2.4

« Last post by roger on October 16, 2017, 03:01:49 PM »

NoiseMap 5.2.4 is currently on limited release. This is because it modifies the database structure in such a way that if you queue a calculation (using the remote server option) then it is no longer possible for earlier versions of NoiseMap to queue calculations on the same database. This has been necessitated by a new feature added at a specific user's request. NoiseMap 5.2.4 is a limited release to those who specifically need the additional database feature.

When we have fully evaluated this new feature, we may standardise it, in which case we will formally release version 5.2.4. Meanwhile, we suggest that users remain on version 5.2.1 or 5.2.2. (NoiseMap 5.2.3 was a development version and will not be formally released )

Support / Why do I get -99 dB for all my results?

« Last post by roger on October 16, 2017, 02:48:31 PM »

Missing results are shown as -99. This indicates that no noise level has been calculated for that case. This can happen in many ways, for example:

A tile was not calculated
The receiver point was outside the angle of view or beyond the cut-off distance
The receiver point was inside a building
There were no noise sources of the type applicable to the chosen calculation

Your case was the last of these - you wanted to calculate the Leq of rail noise sources, but chose the CRTN calculation method.
Each calculation method is applicable to its own type of source:

CRTN for Roads
CRN & TNPM for Rail
BS5228 for Open sites

Please beware that choosing Leq calculations will NOT calculate noise for all types of source.
Please also beware that the choosing a category combination like Road + Rail does not (and cannot) add together noise from road and rail sources.

Adding noise from different types of noise source
To do this, you must

firstly calculate the road sources using CRTN and the rail sources using CRN or TNPM; and then
use the Results Processor to add together the noise from the two types of noise source

Support / How do I import train speed profiles from a shapefile?

« Last post by roger on September 25, 2017, 06:45:57 PM »

We understand that you have a shapefile that gives the speed of a particular train service at 10 m intervals along the track and you would like to import this directly from the shapefile into NoiseMap. We recommend that you proceed as follows:

(a) generate shapefiles with the track geometry split into the 10 m lengths that you require, with a track number assigned to each length;
(b) import these shapefiles with zero tolerance so that NM doesn’t try to further subdivide the tracks (which would add new track numbers and mess up your track numbering)
(c) the imported track numbers will be kept as assigned in the shapefile
(d)define a separate service number for each service speed – so if a service runs from between 0 and 360 km/h and you split this into 10 km/h parts, there are 31 possible speeds for the service.
(e) Define a separate service for each speed, giving 37 separate services – each service will have the same vehicles/noise sources but at a different speed;
(f) Repeat this for each of the train types.
(g) Arrange the service numbers according to the service and its speed, e.g. 100 for the service plus 1 for the speed step gives a service number of 101; at the next speed step up, 100 for the service plus 2 for the speed step gives a service number of 102, and so on.
(h)Save the service definitions described above as a csv file and import to NoiseMap.
(i) From the GIS, export the speed for the service on each segment of track, by using the appropriate service number – eg server 102 is for train type 100 running at the second lowest speed step.
(j) export this data as a csv file – i.e. a spreadsheet with two columns, the service number (with the speed profile step) and the track number;
(k) import the service/track assignments from the csv file, (you may need to use the append function so that existing service assignments are not wiped).

Hints and Tips / How do I add AddressPoint data?

« Last post by roger on August 07, 2017, 06:40:55 PM »

AddressPoint is a database that contains the address of every habitable building in the UK. The address usually includes the map co-ordinates of the building, its house number or name, the road name, the town name and the post code. There may be other information too. It is usually available to local authorities as licensed users, and they can usually make this available to noise mappers as part of a specific project.

Its main use in NoiseMap is to assign addresses to automatically generated receiver points. You should obtain the data as a shapefile. This will contain the information listed above. For use in NoiseMap, you need to ensure that the house number is stored as a string (i.e. the actual characters of the number), rather than as a numerical value. If it is stored as a numerical value, you will not be able to import it.

You load the address shapefile and then go to the shapefile column mapping step. Probably each element of the address (number, name, street, etc) are stored in separate columns of the shapefile. Select all the elements of the address one at a time and map each of them to the All Objects 'Description' column. This will join them into one long string. Thus, if the columns contain: number=35, road=High Street, town=Barchester, post code=AB1 5TU, this will create an object with the description 35, High Street, Barchester, AB1 5TU.

You must now convert the shapefile into NoiseMap AddressPoint objects. Select convert to object type = outline, and then select sub-type AddressPoint. The complete the conversion step. You will now see a AddressPoint Marker in each habitable building (make sure you have set the Display options to show the AddressPoints). These will now be available for labelling any receiver points that you generate around the building.

Support / Can you supply the source terms needed in 'Calculation of Railway Noise'?

« Last post by roger on June 26, 2017, 06:20:13 PM »

Railway vehicles (rolling stock, carriages, locomotives, etc) have changed a great deal since 'Calculation of Railway Noise' was issued in 1995. Most of those vehicles are no longer in use. The situation was slightly improved when Defra issued "Additional railway source terms for 'Calculation of Railway Noise 1995'", published in 2007. It may not cover some of the most recent types of train, but will help.

However, it does not cover Lmax source terms used in our TNPM implementation and we do not have access to this information. If any of our users can assist, this would be of great service. It is difficult to carry out any measurement of source terms, as it is hard to find suitable sites and the measurements take considerable time and resources.

Hints and Tips / How can I improve the look of the 3-d view?

« Last post by roger on June 19, 2017, 02:03:17 PM »

I am seeing vertical 'cliff edges' in the 3-d view, which are not really there. I have also found that some objects seem to be the wrong height above the ground. This is not helpful when I am trying to check the accuracy of the model. And does it mean that the results are wrong?

Generating the 3-d view is a complex process - the features of the model - which are entered as a few lines - have to be turned into surfaces. The lines are regarded as the edges of features, and the first step is to generate points (called vertices) to define where these separate features can be joined to adjacent features. Then the vertices are joined in a series of triangular facets, such that all vertices are joined without leaving any gaps and without any of the facets overlapping. This process requires many iterations, making it slow. But there can be ambiguity, especially where there is sparse data, sometimes causing sub-optimal facetting resulting in the issues described.

Whilst it may be right to describe the result as 'unhelpful', it is as much a symptom of the lack of data as it is of errors in the 3-d creation process. Do not automatically assume that it is just a bug in the 3-d facetting - quite often they can reveal genuine errors in the model. You may well find it helps if you add into the model some ground profiles (we can't call them contours) normal to the original contours. NoiseMap can get their height from the original ground model. Be sure to add enough points on each of these new profiles to adequately represent any changes in the slope of the ground. If you are getting errors around buildings, try to ensure that you are modelling any ground levelling work that may have been done in these areas. You may need to add more ground contours or profiles adjacent to buildings.

Be careful when making these enhancements - if you do it badly, you could make the situation worse.

Do these facetting errors mean that the results are wrong? No, because the noise calculations are not based on the 3-d facets. All the heights are evaluated at calculation time from the actual ground model and object heights. As long as these are correct, then the results will be fine. However, beware of sparse data - the accuracy of the height data will have an effect on the accuracy of the final calculations.

Hints and Tips / I am used to classic SiteNoise, please help with NoiseMap five

« Last post by roger on June 19, 2017, 12:43:30 PM »

Many users have produced 'macros' that help them to create construction noise models, so worry that NoiseMap five will be inconvenient.

Firstly, let's remember that NoiseMap five can read classic SiteNoise files and produce a model from them. So anything you could do in classic SiteNoise YOU CAN STILL DO it!

Just go to File>Import Scheme and the import file dialog will open. you can import a MasterFile (*.mas) or by selecting 'All files' from the drop-down you can import any other noisemap file, like sources, contours, barriers, receivers. If you are going to do this, it is probably best to start with a brand-new empty database file. You can import into an existing one but NM5 then has to add the new items to the existing ones. This can be fiddly if, for example, the same ID number is used in both places. NM5 has been designed to help with this, but since it is so easy to set up a new local database file, it is better if you can start with a fresh one.

Another concern is handling the output. You can do a classic 'Calculate>All receivers' calculation and this will produce the 'classic' output. But it can also produce the 'calculation breakdown' (all the various corrections) as a CSV file that you can easily load into Excel.

We think that it is fiddly to construct the classic 'mnemonic' file structure that classic SiteNoise uses. So, we have provided spreadsheet-type input for all the plant and activity data required by NM5. We think this is easier to understand and to prepare, so we encourage you to look at the context-sensitive help on how to use these. Other advantages include better handling of duplicate or missing entries, and multiple plant being used in an activity (which classic SiteNoise can't do). The spreadsheet lets you assign the activities to multiple working locations at the same time - reducing the number of steps in making the model.

If you are having difficulty, please email us and we will do our best to help.