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How much imagery does the PN-40 hold?


TurLee
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I had a brief introduction to geocaching a few years ago but didn't have the time to get very involved; now retired and trying to bring myself up to speed on the subject. Found a few caches with a basic yellow eTrex and am looking to upgrade equipment, paperless being my main objective.

 

From what I've gathered so far, the Garmin Colorado appears to be flawed and fading – the Oregon appears to be flawed and still under construction, future unknown – Magellan seems pretty much finished; went to a store right before Xmas and they had a display case stuffed full of Magellans, one lonely eTrex in a badly crushed box, and a whole lot of empty spaces where other models had sold out.

 

I've boiled my choices down to being torn between the venerable Garmin 60CSx or the brand new DeLorme PN-40.

 

They sell for pretty much the same price but the Garmin requires a lot of additional stuff to go paperless; maps + PDA + cables (never did buy the $50 cable for my $99 eTrex … and my computer doesn't have a serial port anyway … so that would involve yet another extra) + chargers + software + + +

 

The PN-40 is said to be ready to go right out of the box, with additional maps and images not really required but selling for substantially less than the Garmins. Paperless functionality on the DeLorme is, in reality, still an unknown.

 

So here's the question: about those nifty aerial images on the DeLorme … how much of an area can I put on one? Is it feasible to have an entire state or two (I live very near a state border)? My concern is that most of my geocaching will be spur of the moment things, not “Thursday is geocaching day” and spending the rest of the week preparing for it by planning routes and downloading maps.

 

So do I “have to” plan in advance to download the images or can I have a fairly large area of images ready to just download caches and go?

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A lot of variables come into play in determining an answer to your question. Some types of data have relatively light memory requirements, while others are pretty heavy. If you create detail maps for the PN-40 that have raster imagery at more zoom levels than less, more memory is needed.

 

I have 8GB of memory used for storing USGS quads and color satellite imagery (1 meter resolution)--both raster imagery--and the Delorme TopoUSA vector map data in my immediate area. This is a square of about 1800 sq mi, a little more than 40 miles to each side.

 

Here is a chart I put together form someone in Nevada trying to figure out how much memory would be needed for his state. You can multiply out your desired area to see what it would take. In general, the vectorized Topo7 data doesn't take much, and should probably be considered your basic map data. The imagery is frosting on the cake. I have multi-state Topo7 data (which includes routable roads and 1:100k topo maps), but reserve the imagery for fairly focal areas.

 

Nevadacoverage.jpg

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Thanks for the response – let me see if I got it.

 

I'm really only asking about the 1 meter color satellite images and only for geocaching … car GPS will get me to the site so road navigation not a factor … no long multi-day hikes in wilderness areas; just short hikes along “civilized” paths on the Appalachian Trail, parks, farmland, etc in PA and NJ, never more than a couple hours in and typically much less than that, so detailed trail maps aren't really a factor either. I'm basically just looking at the “how cool is that” factor of the sat images and perhaps saving a few steps when the cache requires a roundabout approach.

 

So having all of PA & NJ is out. Looking at a 100 mile radius circle around home gives me 31,400 square miles at about 3.4 MB/mile = about 104 GB … not really practical … I can download about 8 GB/day so we're looking at a two week download and a real nasty letter from my ISP. Sound about right to you?

 

So if I am understanding correctly, the sat images, while being a great gee whiz thing, really do require planning and downloading just the ones you really want when you want them … yes / no / maybe?

Edited by TurLee
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Thanks for the response – let me see if I got it.

 

I'm really only asking about the 1 meter color satellite images and only for geocaching … car GPS will get me to the site so road navigation not a factor … no long multi-day hikes in wilderness areas; just short hikes along “civilized” paths on the Appalachian Trail, parks, farmland, etc in PA and NJ, never more than a couple hours in and typically much less than that, so detailed trail maps aren't really a factor either. I'm basically just looking at the “how cool is that” factor of the sat images and perhaps saving a few steps when the cache requires a roundabout approach.

 

So having all of PA & NJ is out. Looking at a 100 mile radius circle around home gives me 31,400 square miles at about 3.4 MB/mile = about 104 GB … not really practical … I can download about 8 GB/day so we're looking at a two week download and a real nasty letter from my ISP. Sound about right to you?

 

So if I am understanding correctly, the sat images, while being a great gee whiz thing, really do require planning and downloading just the ones you really want when you want them … yes / no / maybe?

It does take time the first time around for requesting and downloading the imagery from the servers. After that, your planning will be about cutting the location and adding it to your SD card. If you do this by card reader, your export times will be much faster. Do be careful with the card access slot. It is fragile and prone to breakage. As my Dad used to say, if you have to force it or if you are in a rush, you're doing it wrong.

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So halike yving all of PA & NJ is out. Looking at a 100 mile radius circle around home gives me 31,400 square miles at about 3.4 MB/mile = about 104 GB … not really practical … I can download about 8 GB/day so we're looking at a two week download and a real nasty letter from my ISP. Sound about right to you?

 

So if I am understanding correctly, the sat images, while being a great gee whiz thing, really do require planning and downloading just the ones you really want when you want them … yes / no / maybe?

Sounds like you've got a sense of it. The raster imagery can be quite voluminous. With some advanced planning, you could have all your maps created and stored on hard drive or multiple 16 or 32 GB SD cards that you could swap in and out...but it takes some investment of time. Add to the download time the time you need for the computer to convert and compile the data to detail map files that the PN-40 uses, and you'll have some more work to do. I should also add that downloading the data from Delorme is not something of the order of specifying a state's worth of satellite imagery and then sitting back and letting it flow down. The order process requires multiple submissions of relatively small areas, so you have to select, submit, repeat. To cover an entire state will take a while and some patience.

 

My home base sounds like it's more modest than yours; I think it took me about two days to download the data I wanted and create the files for the GPS. I just went down to visit my folks in NC for Christmas; it was easy to download 200 caches and the satellite imagery to cover them. But for someone wanting extensive coverage, it's not real practical. Delorme is mulling some alternative data delivery methods that would alleviate some of the congestion, but that's not yet in place.

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So halike yving all of PA & NJ is out. Looking at a 100 mile radius circle around home gives me 31,400 square miles at about 3.4 MB/mile = about 104 GB … not really practical … I can download about 8 GB/day so we're looking at a two week download and a real nasty letter from my ISP. Sound about right to you?

 

So if I am understanding correctly, the sat images, while being a great gee whiz thing, really do require planning and downloading just the ones you really want when you want them … yes / no / maybe?

Sounds like you've got a sense of it. The raster imagery can be quite voluminous. With some advanced planning, you could have all your maps created and stored on hard drive or multiple 16 or 32 GB SD cards that you could swap in and out...but it takes some investment of time. Add to the download time the time you need for the computer to convert and compile the data to detail map files that the PN-40 uses, and you'll have some more work to do. I should also add that downloading the data from Delorme is not something of the order of specifying a state's worth of satellite imagery and then sitting back and letting it flow down. The order process requires multiple submissions of relatively small areas, so you have to select, submit, repeat. To cover an entire state will take a while and some patience.

 

My home base sounds like it's more modest than yours; I think it took me about two days to download the data I wanted and create the files for the GPS. I just went down to visit my folks in NC for Christmas; it was easy to download 200 caches and the satellite imagery to cover them. But for someone wanting extensive coverage, it's not real practical. Delorme is mulling some alternative data delivery methods that would alleviate some of the congestion, but that's not yet in place.

Ok.. That's it... Now I'm salivating.

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Is there something in the configuration of the device, or the downloading/compilation of the maps that affects the rendering speed? I was out geocaching for the first time today with the color maps installed on an SD card. When I was on a zoom level that would show just the Topo7 type data, the device worked great, but as soon as I zoomed to a level where it display the color image maps, it would take 30-45 seconds to render the screen. I heard the the PN-40 was much faster than the PN-20 at this, but 30+ seconds is really unusable to me.

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Paperless functionality on the DeLorme is, in reality, still an unknown.

Yes, I've seen this opinion expressed on this forum from time to time, but never from those who have cached with the PN-40. No, I do not use paper when I go caching with either my PN-20 or PN-40. Nor do I carry a PDA around with me. Everything for true paperless caching is in the box with the PN-40. Additionally, we expect the release of the widget, Cache Register, in the near future to further enhance the caching experience.

 

So here's the question: about those nifty aerial images on the DeLorme … how much of an area can I put on one? Is it feasible to have an entire state or two (I live very near a state border)? My concern is that most of my geocaching will be spur of the moment things, not “Thursday is geocaching day” and spending the rest of the week preparing for it by planning routes and downloading maps.

 

So do I “have to” plan in advance to download the images or can I have a fairly large area of images ready to just download caches and go?

 

Nothwishtanding the great table presented by Embra, imagery coverage requirements are tough to quantify. Consequently, allow me to cast another light on it. Subsequent to the imagery subscription option, I now cache almost exclusively with the photo imagery: Hi-Res City 133 imagery for around town, and CDOQQ (color aerial photo) imagery for the back country.

 

I ran a Pocket Query with a 5 mile radius around my house and downloaded 236 caches which are within 2GB of CDOQQ imagery of my town.

 

Once I got myPocket Query set up (and that will be a step regardless of your choice of GPSr), it is no more keystoking than buying a 99¢ song from Amazon.com. ;)

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Santa brought me a PN-40 for Christmas. I'm finding it handy to download the equivalent of single USGS 7.5 minute quad at a time. Including color aerials, black and white aerials, and USGS 1:24K topos in the package, a single quad takes around 300-350MB when cut for the PN-40. By far, the biggest chunk of this is the color aerials. I cut this data for all the zoom levels which are reasonably useful to me. YMMV.

 

It does require advance planning. But I cache primarily in parks in the local area. 8-10 quads will keep me busy for quite a while. And if I'm doing a quick trip someplace specific, I can always download and cut just a few 1x1 minute squares to cover the target area. This is (relatively) quick, especially if I'm willing to forego the color aerials. They're very useful in urban/mixed areas, but not usually useful in non-urban parks -- where you get a pretty uniform green carpet.

 

The "wow" factor is compelling. But the stuff really is useful. Over the weekend, I was caching in a local conservation area which was a munitions facility during WWII. Lots of overgrown roads, old foundations, etc. The B&W aerials were really useful for locating old roads which passed near cache locations.

 

Note that you can add and delete map packages on the SD card while the card is in the unit or using a card reader. If you have the space to archive your cut maps on your hard drive, you can develop a library of maps and load them to the unit as needed. Although the process of putting them on the device is slow, the real time consuming part of the process is downloading the data in the first place.

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Is there something in the configuration of the device, or the downloading/compilation of the maps that affects the rendering speed? I was out geocaching for the first time today with the color maps installed on an SD card. When I was on a zoom level that would show just the Topo7 type data, the device worked great, but as soon as I zoomed to a level where it display the color image maps, it would take 30-45 seconds to render the screen. I heard the the PN-40 was much faster than the PN-20 at this, but 30+ seconds is really unusable to me.

I used to work with a Kevin Kessler in HB, is that you?

 

Anyway, I'm assuming that you are using a PN-20? Yes, it is slower on redraws than a PN-40, but I did not find it impossibly slow for geocaching. I really wasn't able to out walk it. I'll run some checks tomorrow.

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Lot of great answers; really cleared up a lot for me. Thanks all.

 

I guess the only way to really get a handle on some of it is try out the different maps and views and see what works for me. It seems to me the PN-40 is about equivalent to getting an Oregon for half price and then not having to deal with the +$ +$ +$ +$ +$ … and getting useful pretty pictures to boot. Decision made.

 

I know for sure the aerial views would already have saved me several hundred yards of fighting through various overgrown briars and stickers when there was a perfectly nice trail running parallel to my path just a short distance away.

 

Now the really hard part ... Should I order it, knowing I won't get it till after the holiday, or should I struggle through the (despised) city traffic and make the trip to J&R today. Anybody up for a ride? ;)

 

Oh, CowboyPapa – have you described you paperless method on the boards here somewhere?

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Is there something in the configuration of the device, or the downloading/compilation of the maps that affects the rendering speed? I was out geocaching for the first time today with the color maps installed on an SD card. When I was on a zoom level that would show just the Topo7 type data, the device worked great, but as soon as I zoomed to a level where it display the color image maps, it would take 30-45 seconds to render the screen. I heard the the PN-40 was much faster than the PN-20 at this, but 30+ seconds is really unusable to me.

How big is the file? The general rule of thumb that seems to help is to keep the rasters to 1GB or less...if they start getting too much above that, performance suffers.

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Here is my 10 step method to get cache descriptions from gc.com to a PN-20 or -40:

1. With a Premium Membership, click on the GPX button of the cache of interest and send it to your PC.

2. On your PC, open up the bundled DeLorme Topo USA 7.0 mapping application.

3. Click on the "Draw" tab, click on the "File..." button, then click on the "Import..." button on the right.

4. Navigate as usual to the folder where you saved the downloaded GPX file and Open it.

5. Click on the "Handheld Export" button.

6. Connect your PN-XX and boot it up.

7. Back in Topo 7, click on the "Exchange" window.

8. Objects stored and recognized by Topo &, including the downloaded caches as Waypoints, will be in the tree structure in the left pane while the objects contained in your PN-XX are shown in the right pane.

10. Select the subject Waypoint in the left pane tree and click the "Send" button.

It is now in your PN-20, -40.

 

Multiple caches may be downloaded via Pocket Query in a similar fashion.

 

Here is a link to the graphics that embra compiled:

http://forums.delorme.com/viewtopic.php?t=...asc&start=0

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Is there something in the configuration of the device, or the downloading/compilation of the maps that affects the rendering speed? I was out geocaching for the first time today with the color maps installed on an SD card. When I was on a zoom level that would show just the Topo7 type data, the device worked great, but as soon as I zoomed to a level where it display the color image maps, it would take 30-45 seconds to render the screen. I heard the the PN-40 was much faster than the PN-20 at this, but 30+ seconds is really unusable to me.

How big is the file? The general rule of thumb that seems to help is to keep the rasters to 1GB or less...if they start getting too much above that, performance suffers.

 

Thanks, my map image was 1.6 Gb. I divvied the map up into 4 maps, and it is a lot more usable now.

 

I really appreciate all the posts people like you and Cowboy Papa put out there. Without your posts, I'd have returned this device or chucked it out the window by now. It's an act of total hubris to expect people to read a 300 page manual to simply send some waypoints to a GPSr.

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OK, I've joined the PN-40 club.

 

Just to prove you guys know what you're talking about, I did break the hinge pin on the SD card door (seems incredible a device that appears to be built like a truck would have such a flimsy piece in such a critical position, but the batteries are holding it in place) … forgot about the advice to use the card reader instead of downloading directly until the download was slowly slogging away.

 

Got the Eastern Region and the Topo 7 installed, upgraded the firmware, went outside and had +/- 12 feet in about 10 minutes. Don't know if it would have gone any better cuz my fingers got cold. I live in a valley with clear sky only to the north and south, hills on east and west, so I'm pretty happy with that.

 

Spent just a few minutes looking at the Topo 7 software … pretty overwhelming right now … looks like I'll have to crack the manual in the morning … and give Cowboy's tutorial a shot.

 

Thanks again for all help.

 

PS: Anybody who is considering the PN-40 and is concerned about the small screen … I can't read anything without my glasses but this screen is so sharp it is no problem at all.

Edited by TurLee
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OK, I've joined the PN-40 club.

 

Just to prove you guys know what you're talking about, I did break the hinge pin on the SD card door (seems incredible a device that appears to be built like a truck would have such a flimsy piece in such a critical position, but the batteries are holding it in place) … forgot about the advice to use the card reader instead of downloading directly until the download was slowly slogging away.

Welcome aboard! Sorry your inaugural voyage included an equipment failure. The silver lining is that the broken clip doesn't really matter much; the batteries do a good job of holding the card in (my PN-20 has been like that for a year). The one thing to watch out for is to make sure it is slid all the way in on the remaining holder--I was careless putting the card back one day, and was momentarily puzzled when the GPS didn't recognize the card. The clip was an insurance policy, as it wouldn't click in unless the card was fully inserted.

 

Without your posts, I'd have returned this device or chucked it out the window by now. It's an act of total hubris to expect people to read a 300 page manual to simply send some waypoints to a GPSr.

Yeah, the PN-40 has sufficient depth to make reading full documentation of most every detail beyond most people's endurance (including mine). Fortunately there are quite a few enthusiasts happy to share their knowledge, especially at the Delorme users' forum. Pass it on when you get a chance.

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Just one more time to thank you guys again for the help.

 

I now have the maps and images for my home area AND the 100 caches closest to my house all installed and ready to go on a paperless geocaching trip … to bad it's dark and there is snow on the ground … maybe tomorrow. ;)

 

I want to mention for those considering the PN-40 that, yes, the Topo software is somewhat intimidating at first but we are not using it on a professional level and don't need to learn everything it can do. With the help files in the program itself and the excellent how-to here from embra and CowboyPapa I really had very little trouble getting everything worked out.

 

Total fiddling time from opening the box to having everything set to go on many a paperless trip was somewhere under 4 hours ... with the biggest chunk of that time spent trying to figure out how to actually get a Pocket Query to my computer. I really doubt that learning any new GPS unit + GSAK + CacheMate + Palm Pilot would take any less time or be any less confusing … now that I have done it once, the next time will take a matter of a few minutes. And by the way, I never did actually open the manual. ;)

 

Thank you, gentlemen.

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