Don't know if this is any use for developer types..

**Skraggy_uk** · 06-29-2004, 04:15 AM

But if you go to the Navtech/Navteq Site you can register to download the developer document explaining the SDAL file/data format that they use for their DVD/CDROMS. Looks pretty hardcore C programming advice, and way over my head, but quite interesting reading.

Might enable someone to code a GPS module for the popular software for the CarPC, to read factory Navtech DVD/CDROMS and use the Navtech voice and routing data?

Admins, move to the software Dev board if you consider it more appropriate there.

Also Brew data samples can be downloaded to aid programming of data access programs and DBs.

The whole Navteq site is pretty interesting.

**mobileh1** · 06-30-2004, 01:23 AM

Thanks thats very cool, the navtech database is one of the best I have used. I'll play around with this...

They want all my personal details, did you already download the spec? If so, could you post it or email it to me?

**Skraggy_uk** · 06-30-2004, 03:22 AM

It's quite a large pdf, but I'll see about zipping and attaching it, or posting a link from a space on my site if the admins have no objections, when I get home from work this evening.

But I warn you, it is very seriously hardcore stuff I there.

**Needstorage** · 06-30-2004, 03:27 AM

Originally Posted by Skraggy_uk

But I warn you, it is very seriously hardcore stuff I there.

Amaze me...

**Skraggy_uk** · 06-30-2004, 04:41 AM

It's all talk about data parcels (not packets). Will post it as soon as I'm home.

**Skraggy_uk** · 06-30-2004, 06:03 AM

Going to try and copy it to my webserver. It is a 1.5meg even when zipped.

You can download it Here (SDAL_spec.zip). If it is slow, don't panic, it is hanging of the upstream to my 512k/256k ADSL line.

**Needstorage** · 06-30-2004, 06:05 AM

Originally Posted by Skraggy_uk

You can download it Here (SDAL_spec.zip).

Thank you... gonna take a look at it...

**mobileh1** · 06-30-2004, 10:31 AM

Thanks, skraggy! got it too.

**Skraggy_uk** · 06-30-2004, 10:35 AM

No probs. Just thought it might be useful for someone wanting the code a Kickass Sat Nav system to use factory DVD and CD's. What better than being able to use the disks that you have already paid for when you bought the car, and as it is an open format, you should be ableuse disks from other manufacturers too (in theory).

**mobileh1** · 06-30-2004, 10:46 AM

'parcels' BTW are like pages in a database, they are sort of like what packets are to a network, except they are fixed size.

When you use oracle, sqlserver.... data is fetched off the disk, or from the cache in pages. A page typically has user-data or index-data, meta data and a free list (typically at the end).

It appears that NavTech hired some RDBMS engineers to to the SDAL because its very similar. They are some interesting storage indexes, b-trees for non-spatial and kd-trees (which are used for orthogonal range searchings - say you were looking for what POI fall into a given bounding rectange, a kd-tree would be fast)...

Something to read tonight now...