BlomWEB

BlomWEB Workshop #1 – Basic functions & measurements

We thought we would introduce some online blogs-come-workshops for those that either already use BlomWEB Viewer, or those that want to know a bit more about it and how it can benefit them.

These workshops will be written and created by Jason Crossley, who is our Commercial Support Coordinator. Jason is responsible for pre and post sales support to a range of different customers as well as to internal Blom staff. So he’s fully up to speed on everything BlomWEB related.
I will hand over to Jason to talk us through some of the basic functions…

One mistake I often find myself making is assuming that people are familiar and know how to use online mapping systems – so Google Maps, Bing Maps and Open Street Maps etc. But not all people do, and some haven’t even heard of them. After all, we all started somewhere! So the purpose of this Blog is to easily demonstrate and explain how to perform a few of the basic features found in BlomWEB, without the hassle of having to sit and read through a stuffy old user manual.

So this is it, this is BlomWEB Viewer (see pic below). It was designed and developed by us at Blom, as an easy access portal for customers to be able to view and interact with Blom’s wide portfolio of data products, all through the simplicity of a standard web browser. No bulky hard drive installs required here, as all data is hosted online.

The BlomWEB Viewer
The BlomWEB Viewer

Navigating the imagery

One of the key functions in any mapping solution is the ability to quickly and intuitively move around the map. This is as difficult as clicking on the map, holding the mouse and dragging around to a different area. See, nice and easy.

Zooming is just as easy and can be achieved by simply rolling the mouse wheel up or down. If you don’t have a mouse wheel, or if you’re using a laptop, you can just as easily use the control panel found on the left of the viewing window:

View controls
View controls

+ will increase the zoom, and will decrease it. It’s as easy as that. Also, that little orange circle is a compass, so it will always point to true North.

Now to view the BlomOBLIQUE imagery, you can simply click on the corresponding N, S, E or W button on the control panel. I won’t insult you by telling you that those are the four cardinal orientations on a compass – oh, it looks like I have. Sorry! This is ‘facing’ direction, so basically what that means is if you click on North, the image will be facing North, East will be facing East. You get the idea…

Tower Of London - BlomOBLIQUE facing North
Tower Of London – BlomOBLIQUE facing North

Change to East and you’ll notice that our little friend the compass has changed too.

Tower Of London - BlomOBLIQUE facing East
Tower Of London – BlomOBLIQUE facing East

You can still pan around the Oblique imagery using the same method as before. Don’t worry, BlomWEB will automatically display the next Oblique image, so you can pan around seamlessly.

Measuring on the imagery

Now one of the key features which sets BlomWEB apart from the free online mapping systems out there, is the ability to perform measurements directly on the imagery. Without getting bogged down in the technical aspects, BlomWEB will extract information from the embedded DTM hidden beneath the imagery. So from that it can perform calculations based on the area you’ve chosen to measure.

Measurements can be performed by simply clicking on the Measurement Tools button, found at the top right of the viewer:

The measurement tools
The measurement tools

From left to right, you have the following tools;

  • Length  – Measures from point A to B, or multiples of this
  • Ground Length – This is essentially the same as Length, but takes into consideration the difference of height values. We’ll take a look at this in more detail further on
  • Area – Calculates an area in m²
  • Bearing – This allows you to draw a line and calculate it’s bearing to true North
  • Ground Elevation – This is height above sea level
  • Height – Ability to measure the height of an object or building
  • Diagonal – Provides a calculation of the hypotenuse of a triangle, so can be used to measure ladder lengths or fire hoses. Again, we’ll take a closer look at this later on
  • Vertical area – This acts the same way as the area tool but allows you to measure the fronts of buildings and structures
  • Clear – This tool just removes all measurements that you’ve currently performed

Let’s start at the beginning with a Length measurement. Click on the tool and you’ll notice that it changes appearance slightly. This is just telling you that it’s turned on and ready to go.
Click on a point on the ground where you want to start the measurement. Why don’t we see how wide this strip of bare earth is?
Click once to begin and then double click to end:

Length measurement
Length measurement

Results are then shown at the end of the line you drew. 25.6m is our width here.
You can also measure more than one line at once, and all you have to do is click once to start, then again to end that line, click once more for every other line, before a final double click to end. Something like this;

Multiple Length measurement
Multiple Length measurement

Results are a bit different using this method. The figures are consecutive, so the first line is 7.9m, then to the next line is 10.6m, and the next 34.3m. These aren’t the results for each line, but the total.

The Ground measurement works exactly the same as above, but will compensate for differences in height. For example you can see there is a step here in the wall as well as a slope where the grass is. BlomWEB will read the DTM and re-calculate for this:

Ground Length measurement
Ground Length measurement

Area measurements are performed much in the same way as Length. So we begin by selecting the button, choosing the first point of the area we want to calculate, and then simply drawing a polygon around that area. Basically you trace whatever you want to measure. Let’s use this Rugby pitch as an example;

Area measurement
Area measurement

All this took was 4 clicks. Three single clicks for the points and a double click to end. And if you’re dying to know, the size of this pitch is 6216.4m².

The Bearing tool behaves in a similar way to the length tool. All you have to do is draw a line and it will tell you the bearing to true North. So again, using the rugby pitch we can see that the centre line is 95.4° to North.

Bearing measurement
Bearing measurement

A simple click to start and double click to end is all you need here.

If we go back to The Tower of London and our little patch of sloping grass, we can better see how to calculate Ground Elevation. This is very straight forward and involves nothing more than clicking on the tool, and again on the point where you’d like to know the height above sea level. I’ve done this for a few points below:

Elevation measurements
Elevation measurements

BlomWEB is reading the embedded DTM and providing us with figures for those precise locations. Clever eh?

Performing Height measurements is as easy as all the other previous tools. Click the tool to begin, then again at the bottom of the object you want to measure, then again at the top – simple as that. It’s important to remember that you must measure from the base up, otherwise you’ll get all sorts of weird and wonderful results!

Height measurement
Height measurement

This is the outer wall of The Tower of London and the highest point is 11.7m, and the lower part of the wall is 7.3m.

Now imagine you’re part of a fire brigade and you’re getting reports of a fire in a block of flats, but you don’t have any details of the building. With BlomWEB you could quickly log-on, view the building from four directions and even calculate approximately how long a ladder and hose you would need. This is where the Diagonal tool comes into its own.
Let’s pretend there is a fire on the 6th floor of this building and the fire escape has been blocked, so our only known access route is through the window.

Diagonal calculation
Diagonal calculation

It’s as easy as clicking on the location of the fire engine (in the centre of the road for our example), then clicking again at the base of the building, then one final time at the end point. So from the image above we can quickly see that from the centre of the road to the 6th floor of this building is 18.9m. That’s pretty invaluable information there, all achieved by just three clicks.

The Vertical Area tool again, is just as intuitive to use as all the others. All that is required is to click at the base of the building/object, and again at the second point, before finally performing two further clicks to finalise the area. This provides the user with an area calculation of the object. I’ve used the same block of flats from our fire example.

Vertical Area measurement
Vertical Area measurement

The size of the side of this building is 576.3m² if you’re curious.

That’s probably enough information to begin with, and I hope explains the measurement functionality that’s available in BlomWEB clearly and that you found it useful. I will continue to put together more of these and hope to cover all of the functionality of BlomWEB, so that people can benefit from them and make the most of the application.

If you have any questions about any of the features and functionality of BlomWEB Viewer, or if you’d like a demo, then please get in touch. You can also check out some BlomWEB videos on our YouTube page.

Thanks

CLICK TO CONTACT US FOR A DEMO