radionut50 wrote:1 – The method of downloading sucks – you set up the area you want in basecamp, and it downloads many many individual images. For just Hamilton city, it has to download 15,000 individual images – taking around 5 hours on a 4 – 6 Mbps connection – for around 220Mbyte total… They need to do something about zipping it into a single file for realistic download performance.
It does. But it works reasonably well for small chunks. E.g. I just download a 1km square around a cache. Much more efficient this way. There is an upper limit somewhere in terms of the number of tiles on can use. I found that having large downloads slowed down map rendering, and that smaller chunks make for better use in a handheld - despite how far they have come, they don't yet have the processing power of a desktop computer
Also, only download in the evening NZ time. It seems very slow when the Americans are awake
The practice of using tiles is common for raster imagery, and is the same way that Google Earth and similar services use. You'll note that BaseCamp does package them up into a single JNX file once downloaded. If Garmin/BirdsEye were to package them up into a single file at the server end, then they would end up with the whole Groundspeak Pocket Query issue of processing and queueing downloads. Far more efficient overall to download individual tiles.
radionut50 wrote:3 – The images have the usual Google Earth location errors –around 10 – 20 meters off in Hamilton, which is very disappointing, and removes some of the advantage of having them . They are not useful to work out which side of a stream you are on etc.
Agree - this is only an issue at the highest quality level when zoomed in. I expect that over time the georeferencing quality will improve and the images will be more accurately referenced. I've also noted that some imagery has clouds in them - not something you commonly see this days.
radionut50 wrote:4 – you cannot vary the transparency of the map over the image – as a result if a map shows a lake it becomes a big blue blob totally obscuring the aerial view in that area. You have to go to map setup and turn off the map to be able to see the photo in these spots.
Probably a case of contacting the map manufacturer and asking them to change the (I think) draw level. It should be easy for them to modify it so that the lake falls below the raster imagery. The introduction of both BirdsEye and Custom Maps may require a few vector maps to change the levels for the vector data.
With a lake, a cunning approach would be to have the existing blue fill polygon fall below the BirdsEye, and have a second transparent polygon for the edge fall above the imagery.
radionut50 wrote:The loader checks your subscription before downloading, and again before loading to the GPS, so I assume in 12 months when my $US30 is exhausted, all the images I have downloaded become unavailable to me.
Incorrect. The subscription is only for access to the web service, and all images will still be available that you have downloaded, they will just be keyed to your GPS, so you will lose access to them if the GPS is lost, sold etc. See the requirements tab on this page
Garmin Website wrote:Expiration Date
The subscription lasts 1 year from the activation date. You will need to renew subscription after 1 year. Imagery downloaded to your GPS device during the 1 year subscription does not expire.
I agree it is not ideal (it is a new service), but after doing some caching recently in the US, having the imagery was very helpful - e.g. in Seattle you could see which pier the cache was going to be on.