© Celtica Mapping 2011 - 2016
Getting your site mapped
Most projects run very smoothly, and this will be helped if you know what the pitfalls are, and what questions we will ask when we visit to survey the site.
1. Decide the boundaries of the area you want mapped. Bigger is not necessarily
better. If the school has extensive playing fields that are to be included on the
map the detail around the buildings may be so small that precision orienteering around
them is not possible. It depends what you need; a lot of fine detail close to the
school gym will be ideal for teaching the techniques of fine map reading and navigation.
The youngsters get the opportunity to do several short courses with both you and
them getting feedback on how successful they are being. Sending youngsters off to
the far corner of the playing fields to find a marker on the only tree for miles
requires minimal navigational skill but will be good for fitness. We often provide
secondary schools with two maps, at different scales, one for skills development
use, the other for longer courses where fitness and stamina are tested. This clearly
costs more than a single map, but is considerably cheaper than making two separate
maps. We need to know this at the outset as we will produce two basemaps at different
scales, and survey the buildings area in greater detail.
2. Make sure that we get an O.S. map extract that covers the whole area you want
mapped. If the extract we are sent covers playing fields that you do not want mapped
make sure we know, otherwise we will not only waste time and money producing a map
that includes them, the area you do want will not be enlarged as much as it could
be, so limiting the accurate placement of the detail we record on our surveying visit.
Ideally send us a paper map (even if we are getting digital mapping data directly
from the local authority) with a line just outside the boundary of the area to be
mapped. This avoids all confusion.
3. The more up to date the basemap or mapping data we get the better.
4. Make sure we get the map (or data) sufficiently in advance of our visit that we
have time to resolve any problems of missing areas and still draw up the basemap(s).
5. Don’t get us to map the school if you know there are about to be major building
works or other changes that will immediately outdate the map. Wait until these are
completed. If money is only available in one financial year, and cannot be carried
forward, speak to us about a written contract payable now for work carried out later
in the year.
6. To minimise our travel/accommodation costs try to co-ordinate with nearby schools
so we can map a cluster in one area. We can then split the travel and accommodation
costs equally between the schools.
7. Decide if you will want an English, Welsh or bilingual key. Bilingual keys can
be cumbersome to fit on the map. Would it be alright, if necessary, to put the key,
or part of it, on the back? Should this be the English or the Welsh key, or both?
8. Decide which areas you would like marked out of bounds. Maps look unattractive with large areas marked out of bounds. The children know, and can be reminded, that they should not be in the car parking areas, or on site roads, so we do not normally mark these out of bounds. They also may not be able physically to get over a high fence surrounding a LPG supply, so again there is no point in marking this out of bounds. However, ponds, which may be used under supervision in natural history lessons are another matter, and we would usually mark these out of bounds unless they were fenced and with a locked gate. Remember the map can also be used for purposes other than orienteering, when a group might be supervised while measuring or recording in an area normally out-of-bounds when orienteering. It is your decision how much or little is actually marked as such.
Notes on the map you supply
We usually work from large scale O.S. maps. The preferred scale is an extract of the 1:2500 map, smaller scales are insufficiently detailed. We are happy to receive this as a photocopy either reproduced at 1:2500 or indeed at a larger size so detail is clearer. Receiving maps on A3 sheets or indeed on multiple A4 sheets is not a problem as long as there is either a referenced grid or an overlap between sheets so we can align them accurately. Sometimes it is useful to have maps at different scales, with an overall small scale map showing the whole site (much of which may be featureless playing fields), but with an enlargement showing the detail of the area around the buildings. It is important that we know EXACTLY what the scale of reproduction is made at, since we set the scale of our basemap by this before we ever see the school. We do check the map scale when we arrive on site, as we have to convert ground distances to map measurements in the course of surveying. If we find there is a discrepancy (in one case we found a map that claimed to be 1:500 was actually 1:437), it slows the surveying process, and adjustments have to be made to our basemap later to correct this.
Our preference is therefore to receive the O.S. map in digital form as a DXF file. Not only does this avoid problems with the scale, but we can import the file directly into the mapping software we use, and need only convert the layers to produce our basemap rather than having to trace over them. This is not only quicker, it is also totally accurate – although contrary to the widely held view the O.S is quite frequently not wholly accurate! We are happy to talk directly to the local authority department who are dealing with the map request about this, and sign the necessary contractor’s agreement for them if required.
It may seem obvious, but clearly WE NEED A MAP OF THE WHOLE OF THE SITE WE ARE BEING ASKED TO MAP. We emphasise this because it does not always happen! The problems arise where the school being mapped have not seen the map extract that we have been sent, and this can result in us making a long wasted journey, for which we have to charge. We strongly recommend that the schools are involved at an early stage so that any questions that arise about the boundaries of the area to be mapped can be resolved well before we visit.
Although we normally use an O.S. map as the source for a basemap we could use an architect’s plan, providing it shows the whole of the area to be mapped, and not just the buildings. As a general rule though the O.S. map is the easiest and cheapest means for a school to provide us with an outline map of the site.
All Ordnance Survey maps are crown copyright. Thus most OS maps, and maps based upon them may not be reproduced without an O.S. Licence. As local authorities, colleges and major public bodies involved in the outdoors normally have a licence, this is not a problem. In councils they are usually used by the planning and highways departments as well as schools, and it will often be them you need to contact, although it may be the IT department.
The licence number, and the standard O.S. copyright statement, will be included on maps we produce for you.
We normally get this information from the paper map you supply us with, or as part of the contractor’s waiver that we are asked to sign if receiving the map in digital format, but it remains your responsibility to check the licence information is correct and the bodies licence covers the proposed use of your map.