The BBC likes to throw out challenges, and the wheel stopped on this one for me and the marketing team I work with.

The BBC One part was the easy bit. BBC One is the place that brings people together to watch an incredibly rich and diverse range of programmes.

It constantly seeks to bring its audience something different that can't be found elsewhere, and encourages the presenters, actors, and producers who work for it to push at the boundaries of what might be expected.

And it does this, though, with a warmth and welcome, which allows everyone to feel at home.

HD is harder. And, along with all the others in the UK trying to explain what HD actually brings to television, we've tried a number of different approaches in the years since we started making and broadcasting programmes in HD.

In the beginning we talked about pixels and picture resolution. That explained things to those who understand television technology, but was baffling to most.

So, at the BBC in recent years, we've focussed on the programmes you can watch in HD, trying to convey the kinds of things we're making in HD.

And, through the choice of shots (close ups, slow-motion sequences), showing what the new HD format brings in terms of picture detail and, therefore, emotional involvement, whether you are watching the trail in SD or in HD.

But BBC One HD is a different channel from BBC HD. It's an old and familiar friend in new, up-to-the-minute clothes. And by now we know that most of you know of HD's existence.

So the trail that has been made tries to be true to BBC One - staying warm and down to earth - and to convey a little of the magic that HD is bringing to the channel.

It features stars from across BBC One, though shows them to you as you've never seen them before.

And while the promo was, of course, produced in HD, we've tried to style it so that even if you are watching them on one of the BBC's SD channels you will get a sense of what HD can mean for the television you already know and love, using colour and storytelling to make up for those extra pixels.

We launched BBC One HD in November. Since then we've been working on ensuring it runs smoothly, and on bringing even more programmes into HD.

EastEnders moved to HD on Christmas Day and, over the coming months, other favourites will join the BBC One HD family, including Have I Got News for You, Formula One, The Boat Race, Songs of Praise, Watchdog, and coverage of the Chelsea Flower Show.

You can always check the programme description in the information bar if you want to know whether a programme is in HD or not. Lots of you have been trying out the channel already, especially over the Christmas holidays.

BBC One HD can be found at Freesat channel 108, Freeview channel 50, Sky channel 143, Virgin channel 108.

BBC HD continues to broadcast HD programmes from all the BBC's channels, and can be found at Freesat channel 109, Freeview channel 54, Sky channel 169, Virgin channel 187.

UPDATE: You can watch the trailer on YouTube.

Danielle Nagler is head of BBC HD.

For a list of frequently asked questions and answers please visit the BBC One HD FAQ page.

Comments made by writers on the BBC TV blog are their own opinions and not necessarily those of the BBC.

The channel will show exactly the same programmes as BBC One in standard definition, but wherever a programme has been made in HD you will be able to experience it in all its glory.

We'll open with The One Show, of course, at 7pm, which shifted to HD this summer. Over the weeks ahead you will also be able to enjoy a new science series from Aardman, led by old friends in Wallace And Gromit's World Of Invention, and the arrival of Film 2010 in HD.

There will also be food, from Jimmy's Food Factory and Nigel Slater, and entertainment with the continuation of The Apprentice and Strictly Come Dancing, Children in Need night, and The Royal Variety Show. Holby City, which has just started its HD life on BBC HD this month, will shift to BBC One HD from November.

Following the dramatic fire at the Queen Vic which led to the departure of everyone's favourite landlady, Peggy Mitchell, the iconic pub is now HD-ready, having been gloriously restored and placed under new management.

I can also reveal that viewers will be able to enjoy all the drama of Christmas Day in Albert Square in HD, as EastEnders broadcasts in HD for the first time.

You can enjoy a taste of what BBC One HD will have to offer - together with the first glimpses of Albert Square in HD - in the video below.

Those shows which aren't made in HD - including initially EastEnders - will still be on BBC One HD but will be 'upscaled'. This means the number of lines in the Standard Definition (SD) picture are almost doubled - from 576 to 1080 - to use the space that an HD picture would occupy. As the original material is SD, the picture quality is not as good as HD.

We also won't be able to bring you regional news programmes or, if you are in Scotland, Wales or Northern Ireland, your own versions of BBC One in HD, and the programmes shown on them.

I'm sorry, this is something that we are working on, but the requirements of HD channels mean that we have to start with just a single version. Of course, you'll still be able to see your national and regional programming on your standard definition BBC One channel

Please don't think BBC HD is disappearing. BBC One HD is allowing us to grow the choices we can offer to you in HD, and BBC HD will be able to grow up alongside it. BBC HD will continue to be the home of many of your HD favourites (including Top Gear, Wimbledon, and our golf coverage).

We're also moving new programming into HD, and I'm delighted to share with you the news that we will be taking the opportunity to bring you the last couple of races of this year's Moto GP in HD as a trial run for the sport on the channel.

BBC HD will still offer children's programmes at the weekend, and great drama, comedy, music and factual programmes from BBC Two, Three and Four throughout the week. The channel will give you a chance to catch up on BBC One HD programmes you may have missed.

Programmes coming from the BBC's other channels to BBC HD will include programmes from BBC One Scotland, Wales and Northern Ireland, which can't be shown on BBC One HD. And we also expect to offer some classics from the archive of HD programmes we've shown since BBC HD launched.

With more hours to accommodate the growing number of HD programmes across the two channels, we'll be able to be more consistent about the HD schedule, showing programmes at the times they are going out elsewhere (which I know is often a source of frustration).

So get ready for November - I'll be keeping you up to date with our progress on Twitter at naglerhd - and start adding the new channel numbers to your favourites.

BBC One HD will be available - from November 3rd - on Freesat channel 108, Freeview channel 50, Sky channel 143 and Virgin Media channel 108. BBC HD will be available - from November 3rd - on Freesat channel 109, Freeview channel 54, Sky channel 169 and Virgin Media channel 187.

Danielle Nagler is head of BBC HD.

For a list of frequently asked questions and answers please visit the BBC One HD FAQ page.

It has been a challenging process of migration. As loyal viewers will know, it is a busy show with lots of different types of subjects covered, and many different production teams compiling the reports that you see.

The sofa needed an upgrade too, although we didn't quite anticipate when we started on discussions that by the time we completed the move its usual occupants would look so radically different.

Yesterday's programme was a great debut for a fast-moving show. The studio looked bright and clean, and I really appreciated some of the extra detail on the films, in particular the items on high school proms and wrestling.

The archive shots from Live Aid made me realise how far what we can do in television has come - and I hope that seeing your favourite early evening magazine programme routinely in HD will add to the enjoyment.

Later this week there's another first - The Open golf in HD. We've broadcast the US Masters for a couple of years now, and those who enjoy the sport have been able to see the detail of one of the world's most lovely championship golf courses.

The Open is of course a different beast - always more rugged and windswept as befits a links course - but I hope that in some ways the benefits that HD can bring will be even more pronounced: Being able to see the ball as it flies above the fairway through the grey skies for example.

So from one point of view, blue skies could be a bit of a disappointment, though I'm sure whatever the weather does between Thursday and Sunday, the sight of the best golfers in the world battling it out together will be enhanced by HD.

Finally, you'll notice some changes in our regular schedule over the coming weeks. We're working to bring you even more HD content, and also to find ways to offer children's programming more effectively.

We'll be on air for longer at the weekends - when we know many of you spend most time with your HD TV - and we'd really welcome your views on how the changes in schedule work for you.

Danielle Nagler is controller of BBC HD.

The One Show continues on BBC One and BBC HD at 7pm each weeknight, and if you want to see last night's episode you can catch it on iPlayer in Standard Definition or High Definition for the next six days.

Most of us don't watch standard definition TV and notice the absence of all that detail, but it is true that watching HD pictures can show you things on television you have never seen before (and may not want to).

When HD television first started, ripples of terror ran through the communities of people who help make the television illusion real for us - the make up artists, set designers, costume designers, props people, and so on.

But they are, of course, highly skilled craftspeople, and have learnt to understand HD and to adapt the ways they work to suit.

We wanted to show you a little more of what HD involves and to share with you the talents of some of those who make it all possible. So we've made a series of short films to give you some insight into how programmes are made in high definition.

They'll be shown on TV in some of the gaps between programmes on BBC HD - and available on the BBC website - but I wanted to share the first two with you here.

They take you to visit the model makers at Aardman in Bristol who care for CBBC's Shaun The Sheep (I'll update this post with a link to this video when it becomes available) and the make-up artists who spend hours creating werewolf wounds on BBC Three's Being Human, as well as the sound engineers responsible for the full (5.1) musical experience on Later with Jools.

I hope they help you to appreciate the often unsung heroes who make HD TV work for the BBC, and for you.

Danielle Nagler is controller of BBC HD

I can now let you know that by the end of the year, you will also be able to enjoy EastEnders, Holby City, QI, Weakest Link and The Apprentice in HD from the BBC, as well as a whole range of returning programmes and new shows.

To ensure that we have space to bring you these programmes in HD, we are also planning to begin broadcasting BBC One in HD this autumn.

That means that in the future - once you have a fully-connected HD set in your home - you will be able to enjoy all the BBC One programmes made in HD (including the vast majority of programmes shown in the evenings) without the need to change channels.

And if you don't fancy a BBC One programme, BBC HD which will operate for longer hours than it has done previously will be able to offer you an alternative including Top Gear, Later With Jools Holland, and new drama, comedy, factual and children's programmes.

These two HD channels from the BBC will be available whatever digital television platform you choose, provided, in the case of Freeview, that HD has rolled out to your area.

I don't know when we will reach a point at which all the BBC's channels are available in HD. To an extent, that may depend on you - whether you choose to buy a new HD set, or to connect up the set you already have but don't use for HD, and ultimately how far you feel that HD is the way you want to watch television.

But I do hope that giving you a choice, night after night, of different HD programmes from the BBC will help you to find something to enjoy in the best quality television can currently offer. If you'd like you can read the full story on the BBC Press Office website.

As the countdown to the World Cup gathers pace, HD is blasting out of pretty much every newspaper, billboard, and television display around. Those of you who have not yet succumbed are no doubt wondering what all the fuss is about.

The BBC will, of course, be offering a large number of ball games over June and July this year - including football from South Africa, tennis from South London, and golf from St Andrews - all on BBC HD, with every ball, every blade of grass, and every bead of sweat more visible than ever before thanks to high definition.

But for those longing for the summer of sport to be over before it has even begun, today's news hopefully makes clear HD from the BBC can offer a whole lot more.

And while we are getting ready for BBC One HD - and the new programmes that will be on it - don't forget that you can sit back and enjoy the summer on BBC HD now.

Danielle Nagler is controller of BBC HD

It is a selection that highlights the breadth of programming on the BBC at any one time. But all those programmes were also made in High Definition (HD) and are shown on the BBC HD channel in addition to standard definition channels as a result.

HD is undoubtedly buzzing this spring - take a look at any advert for anyone who sells TVs and associated boxes, or wander around your local shopping centre or supermarket.

A few years ago HD was specialist television - it is now pretty much everywhere. Around 23 million HD-ready TV sets are estimated to have been sold in the UK, and 70% of the TVs sold in the last three months of 2009 were HD-ready according to the broadcasting regulator Ofcom.

But there are millions of people across the UK who mistakenly believe that once they've got their HD-ready TV they are watching HD pictures, regardless of whether they've installed an HD set-top box or Blu-ray player as well, according to the British Video Association.

So in case you are thinking of investing - either for programmes you are passionate about experiencing in true HD, or perhaps because you want to see the World Cup in June shown in full in HD for the first time - I thought it might be helpful to explain what you need to do, because getting HD pictures to the screen you want to watch them on is not absolutely straightforward.

An HD-ready TV is the first step. But you will also need an HD tuner. That could be built into your television set - the popularity of integrated TVs for general digital television viewing means that there are integrated Freesat HD TVs available, and a range of Freeview HD TVs have already arrived in shops, with more expected.

Alternatively, you will need an HD set-top box, which may or may not be combined with a hard disc recorder (like Sky Plus HD for example). And the days of the Scart lead are numbered - you will need the HD version, known as an HDMI lead - to connect your box if you have one to your television.

You can get HD from all the main digital television providers. Freesat, Sky and Virgin have had HD available for some time. Freeview has just launched a selection of HD channels, with availability across the UK increasing steadily, and a developing range of alternative equipment.

Choosing the right equipment and getting it into your home gives you the ability to watch HD television, but doesn't mean that everything you watch going forward will be HD. HD channels require more capacity than standard definition - so broadcasters need to create them specially and additionally to existing services. So BBC HD, and the other broadcasters' HD channels are separate entries on the channel guide (for the BBC Channel 50 on Freeview HD, 108 on Freesat and Virgin, and 143 on Sky).

Even then, you should not assume that everything on an HD channel is in fact in HD. The BBC HD channel only broadcasts programmes made in HD. To count as an HD programme, the vast majority of the pictures have to have been shot using broadcast-quality HD cameras (not usually the HD camcorders that you might use at home). The pictures then have to have been processed as HD too.

Within an HD programme there may be a small amount of standard definition material - the BBC, in common with most other broadcasters, allows up to 25% of a finished HD programme to be non-HD.

We don't do that to save money - but because sometimes we need to use library pictures or sections of old films which were not made in HD, or we need to use very small cameras - for example for secret filming - which have been slow to develop in HD at the quality level needed.

When the BBC started out in HD television, we wanted to use the channel we had available to offer as much HD programming as possible. We also guessed that we would find programmes we wanted to make in HD across our channels. So BBC HD does not follow the schedule of just one of our existing services but pulls in HD programmes from all of them.

This means that you can find Doctor Who (BBC One), and Doctor Who Confidential (BBC Three) on the channel, as well as Who Do You Think You Are? (BBC One), and Dragon's Den (BBC Two), and the World Cup (largely BBC One), Wimbledon (largely BBC Two) and Glastonbury (BBC Two and BBC Three) this summer.

But the majority of HD channels available in the UK are "simulcast channels". This means that they show exactly the same programmes at the same time as standard definition channels but when the programmes have been made in HD you will be able to view them in HD.

Most sport and much drama are now produced in HD, but it is still developing as a way of making programmes and therefore you will see a certain amount of "upscaled" programme. Upscaling means that the number lines in the Standard Definition (SD) picture are effectively doubled - from 576 to 1080 - to fill the HD screen.

In some people's opinion - and depending on the size of screen and the cameras used to make the programme - this can produce better pictures than on the equivalent SD channel. But it is not HD (and on BBC HD we don't do that).

So, to sum up, if you want to watch HD programmes, they need to be made in HD, shown on an HD channel, and you will need an HD TV coupled with an HD tuner inside the TV or in a box connected with an HDMI lead. There is more detailed advice on our website and trust me - you need no more technical expertise than is required to operate a remote control.

I believe - like many others who watch HD - that HD can deliver simply incredible television. I'd like every HD viewer to experience that, rather than feel let down by pictures that feel rather ordinary, and may in fact be standard definition.

Not every programme will blow you away - I've never found that to be the case in any medium with any range of content, and as programme producers I know that we're still learning how to get the best out of the technology in every situation. But I hope as you travel into HD you will find some outstanding examples of HD.

As someone once wrote to me, it can be like the excitement of the move from black and white to colour, seeing the television screen transform, and the world inside it come alive.

Danielle Nagler is controller of BBC HD

So, over Easter weekend, we're proposing to hand over a number of those choices to you - our viewers.

At the BBC HD's website you will find a selection of 30 programmes we've broadcast over the last year, representing every kind of programme we show, from Life to Shaun The Sheep, from A History Of Christianity, via Psychoville, to Darwin's Dangerous Idea, and of course Doctor Who and Top Gear.

We're asking you to select between them in our Easter Vote and at the end of the voting period we'll find schedule slots for those that you most want to see again. Of course I'm also interested in the thinking behind your choices - and in anything that you feel we've left out.

It's important for the channel team and I to understand the programmes you like to see in HD so that when we take decisions about new programmes - or the moves of existing programmes into HD - we're making the right calls on your behalf.

BBC HD is a youngster as TV channels go: We launched just over two years ago, at a time when very few homes had access to HD, and those who understood the letter combination were few and far between.

Today, HD is prominently available from every television supplier, available to take home with the groceries, and there are numerous channels to choose from. We're now providing programmes viewed by over three million people each month, and rising, but there is still a long way to go in terms of what the BBC is doing, and will do, in HD.

For those of you who have HD already, I hope that my posts on this blog can provide you with some interesting behind-the-scenes detail, and also news on the development of the service.

For those of you interested in HD but who don't yet have it, I hope I can give you an understanding of what we are doing in HD to inform your decision - and I'm sure you will also be able to learn from the others who comment here. There is more information about HD and an overview of the different routes to getting HD on the BBC HD website.

This is the first of what I intend to be regular postings about the BBC and high definition television. I've been writing on the BBC's Internet blog about HD since I took responsibility for BBC HD 18 months ago. As HD grows up, and becomes part of the television mainstream (we're not there yet, but hopefully on the way), this feels like a more appropriate home.

I look forward to sharing the continuing HD story here with you.

UPDATE: The Easter vote has now closed and we're now going through the results. A big thank you to everybody who voted and left feedback on here, and we'll be announcing the results of the vote on Wednesday on the BBC HD page.

Danielle Nagler is head of BBC HD