Re: Possibility of checker for grandfathered polygon based challenge

Before I go about tracking down the polygons I want to make sure such a checker is possible. I know new challenges cannot be published with user defined areas. I own an old one https://coord.info/GC4KX1Y. If I can get the polygons, could a checker be made? Thanks!

Yes, grandfathered polygon-based challenges can have checkers made.

Great! Since I cannot attach files here, once the next step once I have the polygons?

Judging by the challenge description, it sounds like the polygons are low-resolution (rectangles or similar). If so, you should be able to post them in this thread. If they are high-resolution, you'll need to email them. You can go to the Project-GC homepage, enter the username you wish to email and click "Contact" to get to the Geocaching email option (this won't directly allow attachments, but if you include your email address they can email you back).

The format needed would be in decimal degrees. For example, N 44 degrees 30 minutes, W 122 degrees 15 minutes (no idea where this is, just picking some numbers) would be: 44.5,-122.25

The quad challenge poly is small and for the 25 quads can be placed on the forum page
The config must be as in the following example
"Point Sal":{"rect":[35.00000,34.87500,-120.75097,-120.62596]},
"Point Arguello":{"rect":[34.62500,34.50000,-120.75097,-120.62596]},
"Guadalupe":{"rect":[35.00000,34.87500,-120.62596,-120.50096]},
"Casmalia":{"rect":[34.87500,34.75000,-120.62596,-120.50096]}, etc

Please be aware that the quads are in NAD27 and needs converting to WGS84
(Datum and Coordinate Transformation {http://www.cohp.org/coordinate_transformations.html} -only longitude changed.

I think the best way for me to get the coordinates is from the KLM file produced by the website linked on the cache page (http://www.earthsurvey.us/quads/quads.html) which I think already corrects the spheroid issue. For example, the Fort Douglas quad is listed as -111.875,40.875,0 -111.75,40.875,0 -111.75,40.75,0 -111.875,40.75,0 -111.875,40.875,0

To match the format described above I would clean that up to be

"Fort Douglas":{"rect":[-111.875,40.875 -111.75,40.875 -111.75,40.75 -111.875,40.75 -111.875,40.875]}

Is that correct? The example appears to only list two corners rather than four with both latitudes proceeding both longitudes. In my example, the lat/long are paired as usual. Before I do a lot of typing please confirm the format. Thanks!

A rectangle aligned with lines of latitude/longitude only needs two latitude and two longitude coordinates. The KML file seems to have them in the reverse order to the script we'll be using. So your example should be:

"Fort Douglas":{"rect":[40.875,40.75,-111.875,-111.75]}

If not aligned with the lines of latitude/longitude, we'd have to specify each point, using "polypoints" rather than "rect" (and it does auto-close the polygon, so the repeat of the first point at the end is not needed):

"Fort Douglas":{"polypoints":[[[40.875,-111.875],[40.875,-111.75],[40.75,-111.75],[40.75,-111.875]]]}

The longitude is not correct, they can not be round figures and quads are as shown in the example of the Californian quads. Get the original NAD coordinates because in google earth they very often miss the conversion

Thanks! Sorry for the extra work on dealing with those two quads that don't have any caches in Salt Lake county. Just trying to be consistent in qualifications. Unfortunately it doesn't look like the final product is working.



Also even though I have the notification box checked above and I received notifications earlier, they seem to have stopped. I've checked my spam folder, nothing. If you have suggestions on that, please let me know otherwise please be patient, as I may not be as quick to check back without a prompt. Thanks.

I understand now why only two sets of coords are needed.

I don't understand what you mean by the longitude being wrong. It looks fine on google earth. If I plot caches on Google Earth they are in the correct quads based on those coordinates. It really does not make sense to me why I should find the NAD27 coordinates and convert them to WGS84 when I already have WGS84.

When I open the Fort Douglas Quad as a text file, this is what I see:
Full coords are near the bottom. I do see Lat and Long commands above that.

***************************************************************
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2"; xmlns:gx="http://www.google.com/kml/ext/2.2"; xmlns:kml="http://www.opengis.net/kml/2.2"; xmlns:atom="http://www.w3.org/2005/Atom">;
<Placemark>
<name>Fort Douglas</name>
<Snippet maxLines="0"></Snippet>
<styleUrl>http://www.earthsurvey.us/quads/styles.kml#7.5 X 7.5 Minute</styleUrl>
<ExtendedData>
<Data name="State">
<value>UT</value>
</Data>
<Data name="Grid">
<value>7.5 X 7.5 Minute</value>
</Data>
<Data name="Scale">
<value>1:24000</value>
</Data>
<Data name="Year">
<value>2001</value>
</Data>
<Data name="Series">
<value>HTMC</value>
</Data>
<Data name="ID">
<value>5457407</value>
</Data>
<Data name="Size">
<value>24,854,668</value>
</Data>
<Data name="Lon">
<value>-111.8125</value>
</Data>
<Data name="Lat">
<value>40.8125</value>
</Data>
</ExtendedData>
<MultiGeometry>
<Point>
<coordinates>-111.8125,40.8125,0</coordinates>
</Point>
<LineString>
<tessellate>1</tessellate>
<coordinates>
-111.875,40.875,0 -111.75,40.875,0 -111.75,40.75,0 -111.875,40.75,0 -111.875,40.875,0
</coordinates>
</LineString>
</MultiGeometry>
</Placemark>
</kml>

I think what vogelbird is saying is that the quads were originally defined in NAD27 datum. If you take those coordinates and map them using WGS84 you will get quadrangles, but they will be in a different location. According to https://gisgeography.com/datum-transformations/ they will be 60-70m off around Salt Lake. So for your Fort Douglas example, the WGS84 coordinates should be (using https://tool-online.com/en/coordinate-converter.php to convert):

"Fort Douglas":{"rect":[40.87288082,40.74788216,-111.875,-111.75]}

Edit: But if you're happy with those inaccuracies, give us the coordinates you have.



Edited 1 time(s). Last edit at 07/15/2020 03:59AM by sumbloke. (view changes)

Explanation of difference between traditional paper maps and new online US Topo project as of 2009 https://www.usgs.gov/core-science-systems/national-geospatial-program/us-topo-maps-america?qt-science_support_page_related_con=0%23qt-science_support_page_related_con

The Google Earth overlay comes from this data. This challenge has always been based on the online data not the paper maps.

Here is further information including boundary coordinates directly from the USGS concerning the Fort Douglas Quad I've been using as an example.

https://www.sciencebase.gov/catalog/file/get/5e3bc3eae4b0edb47bdefa63?f=__disk__fc%2F7a%2F40%2Ffc7a40c8c1dcc20021408092d2d29523815a3a69&transform=1&allowOpen=true

Map Datums
An incorrect datum, can put you hundreds of meters from your actual position
The datum you have setup in your GPS receiver must match the datum used to create the map you are using. The three common datums in use in the Continental United States are:

NAD 27 CONUS - North American Datum of 1927 for the Continental United States (Common on older USGS maps)
NAD 83 – North American Datum of 1983 (Used on most newer USGS maps)
WGS 84 – World Geodetic System of 1984 (The default datum used by the GPS system)
Most USGS topographic maps are based on an earlier datum called the North American Datum of 1927 or NAD 27. (Some GPS units subdivide this datum into several datums spread over the continent. In the Continental United States use NAD27 CONUS.)

The Global Positioning System uses an earth centered datum called the World Geodetic System 1984 or WGS 84. WGS 84 was adopted as a world standard from a datum called the North American Datum of 1983 or NAD 83. There is typically only a meter or two difference between WGS 84 and NAD 83 in the Continental United States. The difference between WGS 84 and NAD 27 can be as much as 200 meters.

A failure to use the correct datum can introduce hundreds of meters of position error.
The datum is an important component of a coordinate.
A coordinate with an unknown datum is an approximate location at best.
The datum should be written with individual coordinates or included with explanatory notes when many coordinates are used.
Cartographers that include a coordinate grid on their maps, must also specify the datum used.

I made two polygons

According to USGS quads https://project-gc.com/Challenges//52944

According to google earth https://project-gc.com/Challenges//52936

Please tell which poly you like to use and can you fill in the names for the my quad numbers because I have no reference to the names of the squads

Yes, I know what map datums are and understand the differences between them. This is exactly why I'm arguing against bactracking to NAD27.

The standard that has been used to date for this challenge is the US Topo project beginning in 2009 based on this site http://www.earthsurvey.us/quads/quads.html. That data is updated regularly based on new technology. If you look at the date on the data update above, it is Jan 2020. Nowhere can I find a specific statement on what datum the new data is structured. Coordinates from geocaching plot correctly on the overlay using this data. Remember it is with the use of this new data that the monument at four corners moved 2.5 miles.

The point is if someone uses the challenge checker or plots their caches on Google Earth using the link to the overlay I provide, they should get the same answer.

Here is the link to a checker https://project-gc.com/Challenges/GC4KX1Y/52945

The conditions are as such that the checker has to preform two checks

Part 1 checking if all the required quands are filled
Part 2 checking if at least 8 types are in different quads

For this I had to use a multitest script which has no map printing but in the checker remark is a reference the shape file

Can you please give the names of the quads so I can replace the numbers with a name

I'm bummed to hear the map won't print. The test checker https://project-gc.com/Challenges//52936 had it and it looked like it was testing for types. It would be helpful for people figuring out what caches they needed to fill-in empty quads.

Here are the names with comments on the ones that have caches within the quad but not the county. I've hear the Big Dutch John quad may soon be getting a cache with Salt Lake County. Please let me know if that needs clarification. Thank you!!

# on Checker map Quad Name Comment
02 Saltair NE No active caches, the confluence cache GCQHX0 should count toward this quad. Should also check if there is a new cache laced within this quad in county. (As lake dries up more caches are getting placed where there was once water.)

03 Farmington No SLCo caches, but cache must be found within quad. Should also check if there is a new cache laced within this quad in county.

Plug Peak SE - Not required for challenge qualification Since part of goal of challenge is to educate people about maps, it would be great if the outline for this quad could still be shown and the name included in the list.

11 Antelope Island South
12 Baileys Lake
13 Salt Lake City North
14 Fort Douglas
15 Mountain Dell
16 Big Dutch Hollow No SLCo caches, but cache must be found within quad. Should also check if there is a new cache placed within this quad in county.

21 Farnsworth Peak
22 Magna
23 Salt Lake City South
24 Sugar House
25 Mount Aire
26 Park City West
31 Bingham Canyon
32 Copperton
33 Midvale
34 Draper
35 Dromedary Peak
36 Brighton
41 Lowe Peak
42 Tickville Spring
43 Jordan Narrows
44 Lehi

I placed the names behind the numbers because the checker places those in alphabetical order.
This the sequence stays intact.

Because two quads are needing cache finds outside the county boundary I had the setup a third search criteria to allow for those finds

The shape file is adjusted to allow for Plug Peak SE (10) ( stands for horizontal line 1 and vertical line 0)
https://project-gc.com/Challenges//52936

The checker is at https://project-gc.com/Challenges/GC4KX1Y/52945
Example log
[HikingSeal](https://www.geocaching.com/profile/?u=HikingSeal) has used [Project-GC](https://project-gc.com/Challenges/GC4KX1Y/52945 "Project-GC Challenge Checker") to see if they qualified for this challenge and they did.

"Find a different type cache in at least 8 quads of Salt Lake County (UT)" Qualifying 9 / 8, PASSED
"Find a cache in at least 21 quads of Salt Lake County (UT)" Qualifying 21 / 21, PASSED
"Find a cache in at least 2 quads special status" Qualifying 2 / 2, PASSED
All tests, Qualifying 3 / 3, PASSED

Script output
"Find a different type cache in at least 8 quads of Salt Lake County (UT)"
13 Salt Lake City North - Salt Lake County (UT) - 2008-05-17 GC19ZTC - Artesian Systems (Earthcache)
14 Fort Douglas - Salt Lake County (UT) - 2008-07-03 GC8FE0 - The Billboards on the Mountain (Unknown Cache)
23 Salt Lake City South - Salt Lake County (UT) - 2013-04-20 GC4936J - Earth Day CITO at Bend-in-the-River! (Cache In Trash Out Event)
24 Sugar House - Salt Lake County (UT) - 2010-05-01 GC25JVQ - 10 Years! Salt Lake City, Utah (Lost and Found Event Cache)
33 Midvale - Salt Lake County (UT) - 2008-06-08 GCG39T - FOG #10, "And the last shall be first..." (Multi-cache)
34 Draper - Salt Lake County (UT) - 2010-05-16 GC2754V - Sunday Morning Hiking Series #11 - Draper BST (Event Cache)
36 Brighton - Salt Lake County (UT) - 2009-05-09 GC68CF - Brighton Virtual Cache (Virtual Cache)
42 Tickville Spring - Salt Lake County (UT) - 2015-04-27 GC3JYCF - AIR FORCE (LBH#3) (Letterbox Hybrid)
43 Jordan Narrows - Salt Lake County (UT) - 2009-03-10 GCX48F - 99 Bottles of Beer on the wall.. (Traditional Cache)
Qualifying 9 / 8, PASSED

"Find a cache in at least 21 quads of Salt Lake County (UT)"
11 Antelope Island South - Salt Lake County (UT) - 2009-04-24 GC11WQ9 - The Bamberger (Traditional Cache)
12 Baileys Lake - Salt Lake County (UT) - 2009-03-04 GC12ANA - DUCK, duck, duck... #1 (Traditional Cache)
13 Salt Lake City North - Salt Lake County (UT) - 2008-05-03 GC1B4JW - 2008 Spring Jordan River Bike Ride (Event Cache)
14 Fort Douglas - Salt Lake County (UT) - 2008-06-22 GCXZ2G - KIDS CACHE (Traditional Cache)
15 Mountain Dell - Salt Lake County (UT) - 2009-05-09 GC8C71 - One Thousand Cranes (Traditional Cache)
21 Farnsworth Peak - Salt Lake County (UT) - 2009-04-24 GCJXM0 - Schispy's FTF Seafood Raffle # 2 (Multi-cache)
22 Magna - Salt Lake County (UT) - 2009-04-09 GCY0XR - Oquirrh Park Invasion by Reed Mapper&TellFamily 1 (Traditional Cache)
23 Salt Lake City South - Salt Lake County (UT) - 2008-05-03 GC18YET - SLC Degrees of Confluence #46 9S9W (Traditional Cache)
24 Sugar House - Salt Lake County (UT) - 2008-04-12 GCXBX6 - Sugarhouse Bird's Nest (Traditional Cache)
25 Mount Aire - Salt Lake County (UT) - 2008-05-18 GC12FVB - Bill's Arch (Traditional Cache)
26 Park City West - Salt Lake County (UT) - 2009-07-06 GCXX1Z - Willow Heights trailhead (Traditional Cache)
31 Bingham Canyon - Salt Lake County (UT) - 2009-05-08 GCZ5ZF - Stratovolcano to Huge Hole in the Ground (Earthcache)
32 Copperton - Salt Lake County (UT) - 2009-04-25 GCTBYP - Where The MONSTER Trucks Roam (Traditional Cache)
33 Midvale - Salt Lake County (UT) - 2008-04-14 GCX6EA - FLAT TOPS $10 (Traditional Cache)
34 Draper - Salt Lake County (UT) - 2008-05-25 GCZWVQ - A Delicate Matter (Traditional Cache)
35 Dromedary Peak - Salt Lake County (UT) - 2008-06-08 GCJJTA - Cone Heads (Unknown Cache)
36 Brighton - Salt Lake County (UT) - 2009-05-09 GC68CF - Brighton Virtual Cache (Virtual Cache)
41 Lowe Peak - Salt Lake County (UT) - 2012-05-05 GCJF76 - Stetson and Spurs Remembered (Traditional Cache)
42 Tickville Spring - Salt Lake County (UT) - 2009-05-08 GCX2B6 - Cold Hard Cache (Traditional Cache)
43 Jordan Narrows - Salt Lake County (UT) - 2009-03-09 GC15Y83 - An Alphabet Soup Challenge for Utah (Unknown Cache)
44 Lehi - Salt Lake County (UT) - 2009-08-17 GC10MNQ - "Rock" with a view (Traditional Cache)
Qualifying 21 / 21, PASSED

"Find a cache in at least 2 quads with special status"
03 Farmington - Davis County (UT) - 2009-06-03 GCJ4M9 - Cantaloupe Days (Virtual Cache)
16 Big Dutch Hollow - Morgan County (UT) - 2016-07-08 GC6F5GZ - Corridor to the West (Multi-cache)
Qualifying 2 / 2, PASSED

All tests, Qualifying 3 / 3, PASSED

Ugh! Getting frustrated here. I'm no longer getting notifications from this thread. I have checked my spam folder, nothing. Now it's not letting me reply. I have typed the same reply twice. It's not showing up. Is it because I'm trying to include an image? I'm going to post two separate replies. This text one and then one with the image from my checker results. Third time is a charm right.

Thanks! Sorry for the extra work on the two quads that don't have Salt Lake caches. I'm just trying to be consistent with what was done in the past to qualify.

Unfortunately it doesn't look like that part of the final product is not working.



Edited 1 time(s). Last edit at 07/16/2020 09:08PM by HikingSeal. (view changes)

Sorry, I must have clicked the wrong link.

The output is somewhat confusing. The eight quads that are used for the different types appear a second time in the list of the 21 Salt Lake quads with different caches. At least the two with special consideration aren't repeated. Is there any way to get the quads listed once (i.e. combine the outputs)?

Just found one of my original replies. It's way up the thread. Very weird.

The result you printed is from the shape file. This is not the checker and is not attached to the GCcode.
It will never give a green result.

The result I printed is the checker which give green for you and is attached to the GCcode
https://project-gc.com/Challenges/GC4KX1Y/52945

Also I just ran it for someone who is close to qualifying, BFin. It would be great if the quad could be shown with [missing] when the account does not have a qualifying cache. The first version you did had that.

Sorry because of the different criteria this is the best I can make it

OK. Mark it done then. Thanks!