Re: Tiles and zoom and some out of topic and long

Fred Hillhouse

Fred Hillhouse wrote:
I haven't connected to a TNC or GPS yet since the machine doesn't connect to
either, nor will it ever. I plan on moving everything to a laptop this
weekend. This laptop has no internet connection except WiFi on my network.
The laptop is an old Compac Armada M300. It will be connected to a Tracker2
in the vehicle and any helpful tips would be appreciated. Of course I can
always experiment too. I do have an NMEA spigot on my OT2 as well as the
standard serial port running KISS.
If you want APRSIS32 to be generating beacons, you'll need to feed it
NMEA GPS on one port and the KISS on another. I don't interleave the
two. Of course, if you want to use APRSIS32 and can configure the OT2
to forward internally generated beacons out the KISS port, you can use
just the single connection.

The T2 doesn't interleave the GPS NMEA data into the KISS stream either. Not enough memory. I think the TT4 does now but only in TEXT mode.

I added a GTRANS inside my T2 for the purpose of supplying NMEA out. I think I documented it on the T2 WIKI as well. Now the serial port supplies GPS data (Garmin Protocol), a PC interface (KISS) and NMEA. I built a 3 headed serial to support it as well. It works as planned. I shuld be able to exchange the current GPS (Garmin GPS V) nd just continue on like nothing happened. actually I might just throw a mouse type on and forget about it but then I wouldn't have maps when the lpatop wasn't present.

I saw this embedded in the Digest version:
"I'm not even sure the program can total space utilization over 2GB as I'm
not sure how big my variable and never expected someone to download that
many tiles before the purger started removing old ones!"

Do you have a tile limitation with the Windows version? I would probably
only limit tiles to drive space. I am finding I will more trips coming up
and it would be nice to not lose previous downloaded tiles.
The 2GB report was reading the wrong numbers somewhere. I currently
have no limits on anything, but have a ToDo item to stop the tile
downloader if the free space on the target drive falls below some
configurable limit. The most I've ever consumed on my laptop with
browsing around the world and zooming in and out all over the place was
500MB or so.
That is excellent news. I did override the purger already. I found that information in an older post.

Have you considered the USGS tiles from the TerraServer as well? This might
be a very useful tool for SAR.
Many other on-line tile sources have restrictions that I could not (in
conscience) live with. I do not remember what all I looked at, but was the only one I found that was EXPLICITLY open to
everything I was doing and planning to do with map tiles (real-time GPS
use, local caching, pre-fetching). And on top of that, if there were
errors in a user's area, they could just sign up at OSM and put the fix
in for themselves!
The topos are based on maps that were done up to the 70's or maybe a bit later. The aerials are newer and the URBAN aerials are even newer but not available for everywhere. They also have better resolution. They have the 1/4M per pixel. I use the topo for the layout of the land more than for street anyway. And the earth really hasn't changed a whole lot since they were done. ;)

Have you considered being able to use scanned maps? I recently checked out a
universal map downloaded. I have made a couple of maps using a variety of
tiles. SAR might find this useful as well.
I have a ToDo item to support UI-View-type tagged images as background
maps. If you've got 'em, I'm hoping to be able to use 'em.
I have never used UI-View mainly because it was only recently I found a laptop for mobile use. So I don't have any clue what is needed there.

I use ExpertGPS (E-GPS) for the majority of my mapping needs. Actually, this
is what I compare all other map software to. I have the GIS and CAD option
pack. I have been using it for almost as long as it has been out.

My E-GPS topo and aerial tile collection is a good size.
Type 1 (aerial) 3.79GB on disk in 442,587 Files, 72 Folders Type 2 (topo)
5.18GB on disk in 350,089 Files, 65 Folders Type 4 (urban) 68.2MB on disk in
11,488 files, 26 folders
Given that data size, it sounds like an expensive program to be
comparing "all other map software to"? Remember, APRSIS32 isn't
intended to be a mapping solution, it's an APRS communications solution
that happens to support maps as backgrounds for the realtime data display.
Actually the software is $59.95 for the basic version. It comes with zero maps. If you want GIS or CAD support, then it is only a bit more. Geobuddy for geocaching is also $59.95. Check out ExpertGPS. There is a 30-day trial available. If for no other reason than to run it for comparison. I download just about every mapping package. Except for Xastir, I don't have any real knowledge of Linux yet.

You may have seen references to esyGPS on the Tracker2 forum. It is an excellent tool for managing waypoits on a GPS. I used it originally myself for that purpose.

You are right about your intended use. I can except that. Other tiles just might be a reasonable option, again for SAR and such.

I have grabbed most of the tiles in the area I travel in on a regular basis
(commuting, day trips and camping). I also grab tiles along the routes of
longer trips, such as my trip to Arkansas. If your software could use these
tiles as well... ;)
My software will use any 256x256 tiles that adhere to the "Slippy Map"
tile naming and hierarchical store format. See for more
information. Just be aware that if you point APRSIS32 to another
hierarchy of map tiles, the purger might delete things that you wanted
to keep and the fetcher may fill in any holes from OSM!
I will have to read about this "Slippy" thingie. I have heard about it briefly on another forum.

I think the USGS tiles on the Teraserver are different in size (200x200?) and right off hand I couldn't tell you what projection they are in.

I also have a collection of scanned maps that provide additional
entertainment. I am now experimenting with the universal map downloader to
create a 'scanned' map.
Be aware that some of the new "universal map downloader" software goes
directly against the licenses provided for some of their on-line data
sources. I specifically avoided any complicancy (sp?) with such
approaches as I have no desire to be party to a suit involving my
software as an "enabler" of copyright violations. Hence my support for
only OSM.
I noticed the license and won't be purchasing it mainly for that reason.

As for as enabling, if someone wanted to use maps generated from Google or other source, it wouldn't take much effort to make them useful with the software you already have. I understand the OSM tiles and the Google tiles are the same size already and they are referenced to same too. But that is your call and I am good with that. Besides, if OSM has street maps, then the only useful ones for me are the terrain series. I think the topos have them beat.

The scanned maps I am using are those I scan myself and those provided to the boating society for navigating waterways and such. They are labeled 'not for navigational use'. But that is okay because I use then on land to learn about them and to identify offshore points, like lighthouses, rock outcroppings, etc. I hope to get out on a kayak at some point. Scaned maps do require a calibration. E-GPS allows for a 3-point cal. These may or not fit in the ARPS scheme of things.

The E-GPS tile tool as a rectangular box that one draws on the screen and
the selected resolutions are auto magically downloaded. This usually ends up
with a nice collection of tiles that are not needed. Or one can just update
the location on the screen and tiles are downloaded. I recently have put
together a program to simulate a GPS so that E-GPS will get the tiles as the
position is updated. I have to run a route multiple times to get the
different resolutions but it only gets those that are needed to fill the
monitor and a few extra. I can provide a better description of my process if
Yes, can you tell me if it covers the entire area at all of the selected
resolutions with the accompanying geometric expansion of the number of
tiles per layer? Or does it keep a constant area as it zooms into the
extended detail?
If a rectangle is drawn on the map, then the retriever will allow the user to grab any and all tiles at any zoom selected. The rectangle can be any size. While the rectangle is useful, another package (USAPhotomaps-TerraFetcher) allows drawing a polygon and grabbing those within it or creating a route and retrieving along the route.

The retrieval tool is really easy to use but I think the Terraserver has some sort of maximum rate or something. After a larger number of tiles have been downloaded, it seems to slow down the serving of tiles. But I have neither timed it or found a way to measure it. So grabbing large amounts is practical for a limited amount for time. Or it might be caused by my PC going into screen save mode. I don't really know. I just don't grab everything for an entire state (I do have all of NH and large portions of ME, MA and VT). I would bet the OSM server might slow down retrieval as well if someone was going for a whole enchilada or two wth rice and beans included. But at least with tile purging off (for /32), that should only be a single downloading event.

I outline 1x1 degree at a time in the topos and will repeat the grab with a smaller set of aerials. I find the aerial to be less interesting. Part of that is because of my interest of taking the 4x4 off the pavement. Aerials are not much use there.

Lately for my trips, I just use my simulator. I find it works just fine. Currently, it takes a bit of work but that is going to change this week. I do a couple of conversions to get the data into a specific format with Excel. The software is changing to do it without any extra effort.

The simulator does require two serial ports at this time. There should be a way to emulate a serial, I haven't explored it yet. In theory, I shouldn't need anything but a virtual port.

APRSIS32 will fetch the current zoom level and the
ones above and below it (4x below) as you drag the screen around. If
you wait the for yellow circle (background fetch queue progress
indicator) to finish expanding, before dragging again, you can manually
fetch two levels of maps. Your GPS simulator will do the same thing,
provided it moves slowly enough for the fetcher to keep up.
I have a select delay. When I am playing back NMEA data I set it to the rate it was saved at. When I built the NMEA sentence (only RMC at this point) I very the rate to allow for more download time. I usually do this when other things are getting done like eating, sleeping, etc. It has worked quite nicely for APRSISCE/32. When it is in better shape for general use, I would be happy to provide the simulator to those interested.

I have also played with USAPhotoMaps so I have a tile collection for that as
well. Someone wrote a tile grabber that works, mostly. There is a bug or
two. It only works within a UTM zone at a time and with a limited number of
points for routes.
UTM Zone? I'm not familiar with that term?
Rather than mess up an explaination:

Appreciate your work on this software!
And I appreciate the considered questions and suggestions, as long as
you understand that I might take them or leave them on the table!
That goes without saying. I am happy to have found your work and am looking forward to its future!

I jsut hope I don't wear out my welcome with questions and requests! ;)

I am looking forward to my next day to AR. I know have a laptop for mapping and such. With your software, it will be very cool!

Best regards,
Fred, N7FMH

Join to automatically receive all group messages.