2b:null 2c:["$","title",null,{"children":"Map Grids & Scales in SVG | Rob | Labs | Observable"}] 31:T8f8,md` ## Details ### The World Magnetic Model (WMM) > *The World Magnetic Model is the standard model used by the U.S. Department of Defense, the U.K. Ministry of Defence, the North Atlantic Treaty Organization (NATO) and the International Hydrographic Organization (IHO), for navigation, attitude and heading referencing systems using the geomagnetic field. It is also used widely in civilian navigation and heading systems. The model, associated software, and documentation are distributed by NCEI on behalf of NGA. The model is produced at 5-year intervals, with the current model expiring on December 31, 2019.* > **12/10/2019**: *WMM2020 Release. The full release of the WMM (WMM2020) is now available. All WMM products and services have been updated.* > **8/1/2019**: *World Magnetic Model 2020 Release Date Announced. As part of the regular update cycle of the World Magnetic Model, NCEI, in collaboration with the British Geological Survey will release the WMM2020 on December 10, 2019.* > Source: https://www.ngdc.noaa.gov/geomag/WMM/DoDWMM.shtml * NOAA has an [iPhone](https://apps.apple.com/app/id910578825) and [Android](https://play.google.com/store/apps/details?id=gov.noaa.ngdc.wmm2) apps that make use of the WMM * Obtain raw WMM coefficients from either * [NOAA.gov](https://www.ngdc.noaa.gov/geomag/WMM/soft.shtml) * [earth-info.nga.mil](http://earth-info.nga.mil/GandG/update/index.php?action=home) * \`wget -O tmp/WMM2015v2.zip https://earth-info.nga.mil/GandG/update/wgs84/data/WMM2015v2.zip\` * After downloading, you can review the README file * In the Zip file, look for the file \`WMM.COF\` and update your software with this data * The GeoMagJS library has a function that converts the raw Coefficients file to a JSON structure. * The header data from the WMM used in this page = \`{"epoch":"${WMM.epoch}", "model":"${WMM.model}", "modelDate":"${WMM.modelDate}"}\` * February 2019, World Magnetic Model (WMM2015v2) - [Technical Report](https://www.ngdc.noaa.gov/geomag/WMM/data/WMM2015/WMM2015v2_TechnicalNote.pdf) about the out of cycle release development ### geomagJS * https://github.com/cmweiss/geomagJS * Use the \`geoMagFactory\` to generate a method called \`geoMag\` * pass into \`geoMag\` the latitude, longitude, altitude, date `32:T81d,md` ### Map Grids & Scales in SVG Generate PDF margin info in SVG. Useful for printed or web maps. * Computes Scale in Kilometers, Statute Miles, & Nautical Miles * Computes Slope Guide * Uses data from the World Magnetic Model from [NOAA.gov](https://www.ngdc.noaa.gov/geomag/WMM/soft.shtml) to compute magnetic declination. Originally written in \`javascript\` by [spatialillusions/margin-info](https://github.com/spatialillusions/margin-info) and inspired by the original demo for [Margin Information](https://spatialillusions.com/demos/margininfo/index.html) & [Grid Declination Diagrams](https://spatialillusions.com/demos/GridDeclinationDiagrams/index.html). ----- Ported to ${html``} in Sep 2019. This Notebook is useful for testing input parameters for Scale, Slope Guide, and Grid Declination assets that are generated in SVG. *Update Sep 7, 2019* — Tested in Chrome, Opera, & Safari. Running down problems with SVG rendering of fonts in FireFox. --- ![grid-declination](https://user-images.githubusercontent.com/118112/64483428-8a890780-d1b6-11e9-9dd9-ec66d33e6052.gif)

`33:T54f,md` Test result of computing \`Decl\` in Javascript

Date     HAE   Lat   Long   Decl   computed using GeoMagJS, geoMag(Lat, Long, HAE, Date)
2020.0    66    14    143    0.12  ${geoMag( 14,  143, 66, new Date(2020, 1, 1)).dec}
2020.0    18     0     21    1.05  ${geoMag(  0,   21, 18, new Date(2020, 1, 1)).dec}
2020.5     6   -36   -137   20.16  ${geoMag(-36, -137,  6, new Date(2020, 6, 1)).dec}
2020.5    63    26     81    0.43  ${geoMag( 26,   81, 63, new Date(2020, 6, 1)).dec}
2020.0    28    89   -121 -112.41  ${geoMag( 89, -121, 28, new Date(2020, 1, 1)).dec}
2020.0    48    80    -96  -37.40  ${geoMag( 80,  -96, 48, new Date(2020, 1, 1)).dec}
2020.0    54    82     87   51.30  ${geoMag( 82,   87, 54, new Date(2020, 1, 1)).dec}
2020.0    65    43     93    0.71  ${geoMag( 43,   93, 65, new Date(2020, 1, 1)).dec}
2020.0    51   -33    109   -5.78  ${geoMag(-33,  109, 51, new Date(2020, 1, 1)).dec}
2020.0    39   -59     -8  -15.79  ${geoMag(-59,   -8, 39, new Date(2020, 1, 1)).dec}
2020.0     3   -50   -103   28.10  ${geoMag(-50, -103,  3, new Date(2020, 1, 1)).dec}
2020.0    94   -29   -110   15.82  ${geoMag(-29, -110, 94, new Date(2020, 1, 1)).dec}
2020.0    66    14    143    0.12  ${geoMag( 14,  143, 66, new Date(2020, 1, 1)).dec}
2020.0    18     0     21    1.05  ${geoMag(  0,   21, 18, new Date(2020, 1, 1)).dec}

`34:T1886,// https://raw.githubusercontent.com/cmweiss/geomagJS/master/WMM.COF // To simplify porting from Node, // `wmm` is generated from /* // compute Magnetic Declination var cof2Obj = require("./geomagJS/cof2Obj") cof = fs.readFileSync("./geomagJS/WMM.COF") var WMM = cof2Obj.cof2Obj(cof.toString()) console.log(WMM) */ WMM = { const data = { epoch: 2020, model: 'WMM-2020', modelDate: '12/10/2019', wmm: [ { n: 1, m: 0, gnm: -29404.5, hnm: 0, dgnm: 6.7, dhnm: 0 }, { n: 1, m: 1, gnm: -1450.7, hnm: 4652.9, dgnm: 7.7, dhnm: -25.1 }, { n: 2, m: 0, gnm: -2500, hnm: 0, dgnm: -11.5, dhnm: 0 }, { n: 2, m: 1, gnm: 2982, hnm: -2991.6, dgnm: -7.1, dhnm: -30.2 }, { n: 2, m: 2, gnm: 1676.8, hnm: -734.8, dgnm: -2.2, dhnm: -23.9 }, { n: 3, m: 0, gnm: 1363.9, hnm: 0, dgnm: 2.8, dhnm: 0 }, { n: 3, m: 1, gnm: -2381, hnm: -82.2, dgnm: -6.2, dhnm: 5.7 }, { n: 3, m: 2, gnm: 1236.2, hnm: 241.8, dgnm: 3.4, dhnm: -1 }, { n: 3, m: 3, gnm: 525.7, hnm: -542.9, dgnm: -12.2, dhnm: 1.1 }, { n: 4, m: 0, gnm: 903.1, hnm: 0, dgnm: -1.1, dhnm: 0 }, { n: 4, m: 1, gnm: 809.4, hnm: 282, dgnm: -1.6, dhnm: 0.2 }, { n: 4, m: 2, gnm: 86.2, hnm: -158.4, dgnm: -6, dhnm: 6.9 }, { n: 4, m: 3, gnm: -309.4, hnm: 199.8, dgnm: 5.4, dhnm: 3.7 }, { n: 4, m: 4, gnm: 47.9, hnm: -350.1, dgnm: -5.5, dhnm: -5.6 }, { n: 5, m: 0, gnm: -234.4, hnm: 0, dgnm: -0.3, dhnm: 0 }, { n: 5, m: 1, gnm: 363.1, hnm: 47.7, dgnm: 0.6, dhnm: 0.1 }, { n: 5, m: 2, gnm: 187.8, hnm: 208.4, dgnm: -0.7, dhnm: 2.5 }, { n: 5, m: 3, gnm: -140.7, hnm: -121.3, dgnm: 0.1, dhnm: -0.9 }, { n: 5, m: 4, gnm: -151.2, hnm: 32.2, dgnm: 1.2, dhnm: 3 }, { n: 5, m: 5, gnm: 13.7, hnm: 99.1, dgnm: 1, dhnm: 0.5 }, { n: 6, m: 0, gnm: 65.9, hnm: 0, dgnm: -0.6, dhnm: 0 }, { n: 6, m: 1, gnm: 65.6, hnm: -19.1, dgnm: -0.4, dhnm: 0.1 }, { n: 6, m: 2, gnm: 73, hnm: 25, dgnm: 0.5, dhnm: -1.8 }, { n: 6, m: 3, gnm: -121.5, hnm: 52.7, dgnm: 1.4, dhnm: -1.4 }, { n: 6, m: 4, gnm: -36.2, hnm: -64.4, dgnm: -1.4, dhnm: 0.9 }, { n: 6, m: 5, gnm: 13.5, hnm: 9, dgnm: -0, dhnm: 0.1 }, { n: 6, m: 6, gnm: -64.7, hnm: 68.1, dgnm: 0.8, dhnm: 1 }, { n: 7, m: 0, gnm: 80.6, hnm: 0, dgnm: -0.1, dhnm: 0 }, { n: 7, m: 1, gnm: -76.8, hnm: -51.4, dgnm: -0.3, dhnm: 0.5 }, { n: 7, m: 2, gnm: -8.3, hnm: -16.8, dgnm: -0.1, dhnm: 0.6 }, { n: 7, m: 3, gnm: 56.5, hnm: 2.3, dgnm: 0.7, dhnm: -0.7 }, { n: 7, m: 4, gnm: 15.8, hnm: 23.5, dgnm: 0.2, dhnm: -0.2 }, { n: 7, m: 5, gnm: 6.4, hnm: -2.2, dgnm: -0.5, dhnm: -1.2 }, { n: 7, m: 6, gnm: -7.2, hnm: -27.2, dgnm: -0.8, dhnm: 0.2 }, { n: 7, m: 7, gnm: 9.8, hnm: -1.9, dgnm: 1, dhnm: 0.3 }, { n: 8, m: 0, gnm: 23.6, hnm: 0, dgnm: -0.1, dhnm: 0 }, { n: 8, m: 1, gnm: 9.8, hnm: 8.4, dgnm: 0.1, dhnm: -0.3 }, { n: 8, m: 2, gnm: -17.5, hnm: -15.3, dgnm: -0.1, dhnm: 0.7 }, { n: 8, m: 3, gnm: -0.4, hnm: 12.8, dgnm: 0.5, dhnm: -0.2 }, { n: 8, m: 4, gnm: -21.1, hnm: -11.8, dgnm: -0.1, dhnm: 0.5 }, { n: 8, m: 5, gnm: 15.3, hnm: 14.9, dgnm: 0.4, dhnm: -0.3 }, { n: 8, m: 6, gnm: 13.7, hnm: 3.6, dgnm: 0.5, dhnm: -0.5 }, { n: 8, m: 7, gnm: -16.5, hnm: -6.9, dgnm: 0, dhnm: 0.4 }, { n: 8, m: 8, gnm: -0.3, hnm: 2.8, dgnm: 0.4, dhnm: 0.1 }, { n: 9, m: 0, gnm: 5, hnm: 0, dgnm: -0.1, dhnm: 0 }, { n: 9, m: 1, gnm: 8.2, hnm: -23.3, dgnm: -0.2, dhnm: -0.3 }, { n: 9, m: 2, gnm: 2.9, hnm: 11.1, dgnm: -0, dhnm: 0.2 }, { n: 9, m: 3, gnm: -1.4, hnm: 9.8, dgnm: 0.4, dhnm: -0.4 }, { n: 9, m: 4, gnm: -1.1, hnm: -5.1, dgnm: -0.3, dhnm: 0.4 }, { n: 9, m: 5, gnm: -13.3, hnm: -6.2, dgnm: -0, dhnm: 0.1 }, { n: 9, m: 6, gnm: 1.1, hnm: 7.8, dgnm: 0.3, dhnm: -0 }, { n: 9, m: 7, gnm: 8.9, hnm: 0.4, dgnm: -0, dhnm: -0.2 }, { n: 9, m: 8, gnm: -9.3, hnm: -1.5, dgnm: -0, dhnm: 0.5 }, { n: 9, m: 9, gnm: -11.9, hnm: 9.7, dgnm: -0.4, dhnm: 0.2 }, { n: 10, m: 0, gnm: -1.9, hnm: 0, dgnm: 0, dhnm: 0 }, { n: 10, m: 1, gnm: -6.2, hnm: 3.4, dgnm: -0, dhnm: -0 }, { n: 10, m: 2, gnm: -0.1, hnm: -0.2, dgnm: -0, dhnm: 0.1 }, { n: 10, m: 3, gnm: 1.7, hnm: 3.5, dgnm: 0.2, dhnm: -0.3 }, { n: 10, m: 4, gnm: -0.9, hnm: 4.8, dgnm: -0.1, dhnm: 0.1 }, { n: 10, m: 5, gnm: 0.6, hnm: -8.6, dgnm: -0.2, dhnm: -0.2 }, { n: 10, m: 6, gnm: -0.9, hnm: -0.1, dgnm: -0, dhnm: 0.1 }, { n: 10, m: 7, gnm: 1.9, hnm: -4.2, dgnm: -0.1, dhnm: -0 }, { n: 10, m: 8, gnm: 1.4, hnm: -3.4, dgnm: -0.2, dhnm: -0.1 }, { n: 10, m: 9, gnm: -2.4, hnm: -0.1, dgnm: -0.1, dhnm: 0.2 }, { n: 10, m: 10, gnm: -3.9, hnm: -8.8, dgnm: -0, dhnm: -0 }, { n: 11, m: 0, gnm: 3, hnm: 0, dgnm: -0, dhnm: 0 }, { n: 11, m: 1, gnm: -1.4, hnm: -0, dgnm: -0.1, dhnm: -0 }, { n: 11, m: 2, gnm: -2.5, hnm: 2.6, dgnm: -0, dhnm: 0.1 }, { n: 11, m: 3, gnm: 2.4, hnm: -0.5, dgnm: 0, dhnm: 0 }, { n: 11, m: 4, gnm: -0.9, hnm: -0.4, dgnm: -0, dhnm: 0.2 }, { n: 11, m: 5, gnm: 0.3, hnm: 0.6, dgnm: -0.1, dhnm: -0 }, { n: 11, m: 6, gnm: -0.7, hnm: -0.2, dgnm: 0, dhnm: 0 }, { n: 11, m: 7, gnm: -0.1, hnm: -1.7, dgnm: -0, dhnm: 0.1 }, { n: 11, m: 8, gnm: 1.4, hnm: -1.6, dgnm: -0.1, dhnm: -0 }, { n: 11, m: 9, gnm: -0.6, hnm: -3, dgnm: -0.1, dhnm: -0.1 }, { n: 11, m: 10, gnm: 0.2, hnm: -2, dgnm: -0.1, dhnm: 0 }, { n: 11, m: 11, gnm: 3.1, hnm: -2.6, dgnm: -0.1, dhnm: -0 }, { n: 12, m: 0, gnm: -2, hnm: 0, dgnm: 0, dhnm: 0 }, { n: 12, m: 1, gnm: -0.1, hnm: -1.2, dgnm: -0, dhnm: -0 }, { n: 12, m: 2, gnm: 0.5, hnm: 0.5, dgnm: -0, dhnm: 0 }, { n: 12, m: 3, gnm: 1.3, hnm: 1.3, dgnm: 0, dhnm: -0.1 }, { n: 12, m: 4, gnm: -1.2, hnm: -1.8, dgnm: -0, dhnm: 0.1 }, { n: 12, m: 5, gnm: 0.7, hnm: 0.1, dgnm: -0, dhnm: -0 }, { n: 12, m: 6, gnm: 0.3, hnm: 0.7, dgnm: 0, dhnm: 0 }, { n: 12, m: 7, gnm: 0.5, hnm: -0.1, dgnm: -0, dhnm: -0 }, { n: 12, m: 8, gnm: -0.2, hnm: 0.6, dgnm: 0, dhnm: 0.1 }, { n: 12, m: 9, gnm: -0.5, hnm: 0.2, dgnm: -0, dhnm: -0 }, { n: 12, m: 10, gnm: 0.1, hnm: -0.9, dgnm: -0, dhnm: -0 }, { n: 12, m: 11, gnm: -1.1, hnm: -0, dgnm: -0, dhnm: 0 }, { n: 12, m: 12, gnm: -0.3, hnm: 0.5, dgnm: -0.1, dhnm: -0.1 } ] } return data; }35:[] 2f:{"id":"79852cb455f3e668","slug":"map-grids-scales-in-svg","title":"Map Grids & Scales in SVG","thumbnail":"b36dc4e5c80b835ee8ccc656c3845efc5bbf1d38f2f7cebe315add6f3a2a332a","access_level":"public","create_time":"$D2019-09-06T20:20:39.378Z","update_time":"$D2020-01-02T22:09:42.619Z","view_time":null,"first_public_time":"$D2019-09-06T22:44:09.493Z","fork":false,"stars":17,"starred":false,"owner":{"type":"team","id":"4fb28e57b1ee7ad7","login":"roblabs","name":"Rob | Labs","avatar_url":"https://avatars-next.observableusercontent.com/a46c63fe02259f75113a4e65721ca91dcd78e54ad768500cc6c0975a9fe307a2","tier":"starter_2024"},"version":1372,"publish_version":1372,"role":null,"authored":false,"authors":[{"type":"individual","id":"979e07e6bb09b05a","login":"roblabs","name":"Rob | Labs","avatar_url":"https://avatars-next.observableusercontent.com/a46c63fe02259f75113a4e65721ca91dcd78e54ad768500cc6c0975a9fe307a2","tier":null}],"members":[{"type":"individual","id":"979e07e6bb09b05a","login":"roblabs","name":"Rob | Labs","avatar_url":"https://avatars-next.observableusercontent.com/a46c63fe02259f75113a4e65721ca91dcd78e54ad768500cc6c0975a9fe307a2","tier":null,"role":"editor"}],"comments":[{"id":"4a0c93fe88ccb111","reply_to_id":null,"content":"These arrows and data displays are all relative to Universal Transverse Mercator grid zones. https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system\n\nDo you have examples of UTM web maps people are using this for?","create_time":"$D2021-02-27T07:58:04.455Z","update_time":null,"resolved":true,"user":{"type":"individual","id":"ddd7235babc79ce0","login":"jrus","name":"Jacob Rus","avatar_url":"https://avatars-next.observableusercontent.com/c33dbeed76527c50e64208b0e005e0b6e54a3bef2a14ea6a823f1c7de4867662","tier":null}},{"id":"287b093812e9394c","reply_to_id":"4a0c93fe88ccb111","content":"Please see the original repo, https://github.com/spatialillusions/margin-info, which may describe where it was used. This application could also be used for print maps.","create_time":"$D2021-02-27T16:41:26.115Z","update_time":null,"resolved":true,"user":{"type":"individual","id":"979e07e6bb09b05a","login":"roblabs","name":"Rob | Labs","avatar_url":"https://avatars-next.observableusercontent.com/a46c63fe02259f75113a4e65721ca91dcd78e54ad768500cc6c0975a9fe307a2","tier":null}}],"custom_thumbnail":false,"trashed":false,"subscribed":null,"forks":3,"collection":null,"type":"notebook","body":{"title":"Map Grids & Scales in SVG","cells":[{"id":792,"value":"body = md`# Map Grids & Scales in SVG\n\nGenerate Magnetic Declination, slopes & scales for printed or web maps. You can see the details on the World Magetic Model data that makes up this map by going to [observablehq.com/@roblabs/map-grids-scales-in-svg](https://observablehq.com/@roblabs/map-grids-scales-in-svg). \n
\n

${usaMapGeoMag}

${viewof usaMap}

\n\nYou chose the point:\n

\nDDS = ${new geodesy.LatLon(usaMap[1], usaMap[0]).toString()}\nDMS = ${new geodesy.LatLon(usaMap[1], usaMap[0]).toString('dms')}\nUTM = ${new geodesy.LatLon(usaMap[1], usaMap[0]).toUtm()}\n

\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":609,"value":"viewof usaMap = usaMapCoordinates({\n title: \"Choose a point in the US to see the change in Magnetic Declination.\",\n description: \"\\nWMM Data: {\\'epoch = '\"+ WMM.epoch + \", 'model' = '\" + WMM.model + \"', 'modelDate' = \" + WMM.modelDate + \"'}\",\n width: 500,\n height: 850,\n value: [-116.8, 33]\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":669,"value":"usaMapGeoMag = {\n let utmCoord = new geodesy.LatLon(usaMap[1], usaMap[0]).toUtm()\n let utmZoneHemisphere = utmCoord.zone + utmCoord.hemisphere\n let TrueNorth = utmCoord.convergence\n \n let computeGeoMag = geoMag(usaMap[1], usaMap[0], 0, new Date())\n let svg = griddeclinationdiagram(TrueNorth, computeGeoMag.dec, year, utmZoneHemisphere, gridColor)\n return html`${svg}`\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":832,"value":"md`

`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":325,"value":"$31","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":0,"value":"$32","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":502,"value":"md`\n

\n# Test Scale, Slope Guide & Magnetic Declination Grid\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":182,"value":"md`## Scale`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":51,"value":"viewof units = checkbox({\n title: \"Units\",\n description: \"Pick your favorite scale units. Adjusts both the Scale and the Slope Guide.\",\n options: [\"showkm\", \"showmiles\", \"shownautical\"],\n value: [\"showkm\", \"showmiles\", \"shownautical\"],\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":72,"value":"viewof scale = slider({\n title: \"Scale, 1:\",\n description: \"Slider moves in units of 500.\",\n min: 1000,\n max: 500000,\n step: 500,\n value: 2500\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":32,"value":"html`${sb}`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":80,"value":"sb = {\n \n var showkm, showmiles, shownautical = false;\n \n for (let i = 0; i <= units.length - 1; ++i) {\n switch (units[i]) {\n case \"showkm\":\n showkm = true;\n break;\n case \"showmiles\":\n showmiles = true;\n break; \n case \"shownautical\":\n shownautical = true;\n break;\n\n default: \n showkm, showmiles, shownautical = true;\n }\n }\n return scalebar(scale, showkm, showmiles, shownautical);\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":185,"value":"md`

`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":157,"value":"md`## Slope Guide`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":37,"value":"html`${sg}`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":175,"value":"sg = {\n return slopeguide(scale, 40) \n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":164,"value":"md`

`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":214,"value":"md`## Grid Declination`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":243,"value":"viewof year = text({\n title: \"Year\", \n description: \"A label used in the Grid-Magnetic angle label.\",\n value: \"2019\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":249,"value":"viewof UTMzone = text({\n title: \"UTM Zone\", \n description: \"A label used on top of the Grid North line.\",\n value: \"11S\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":265,"value":"viewof gridColor = color({\n value: \"#000000\",\n title: \"Grid Color\",\n description: \"The original Github project allows for changing the color.\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":220,"value":"viewof TrueNorth = slider({ // TrueNorth MagneticNorth year zone color\n title: \"True North\",\n description: \"Range is (-1, 1).\",\n min: -1,\n max: 1,\n step: .1,\n value: 0\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":230,"value":"viewof MagneticNorth = slider({ // TrueNorth MagneticNorth year zone color\n title: \"Magnetic North\",\n description: \"Range is (-20, 20).\",\n min: -20,\n max: 20,\n step: .5,\n value: 11.07\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":43,"value":"html`${grid}`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":218,"value":"grid = {\n return griddeclinationdiagram(TrueNorth, MagneticNorth, year, UTMzone, gridColor)\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":405,"value":"md`

\n### World Map`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":439,"value":"md`Using data from the [World Magnetic Model](#the-world-magnetic-model-wmm), The header data from the WMM used in this page = \\`{\"epoch\":\"${WMM.epoch}\", \"model\":\"${WMM.model}\", \"modelDate\":\"${WMM.modelDate}\"}\\``","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":836,"value":"md`\n

${worldMapMagDec}

${viewof worldMap}

\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":295,"value":"// viewof map = usaMapCoordinates({\nviewof worldMap = worldMapCoordinates({\n title: \"Map for choosing Latitude, Longitude\",\n description: \"WMM Data: {\\'epoch = '\"+ WMM.epoch + \", 'model' = '\" + WMM.model + \"', 'modelDate' = \" + WMM.modelDate + \"'}\",\n width: 500,\n value: [-116.8, 33]\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":393,"value":"worldMapMagDec = {\n \n let utmCoord = new geodesy.LatLon(worldMap[1], worldMap[0]).toUtm()\n let utmZoneHemisphere = utmCoord.zone + utmCoord.hemisphere\n let TrueNorth = utmCoord.convergence\n \n let computeGeoMag = geoMag(worldMap[1], worldMap[0], 0, new Date()).dec\n let svg = griddeclinationdiagram(TrueNorth, MagneticNorth, year, utmZoneHemisphere, gridColor)\n \n var log = \"https://SERVER.com/default/margin-info?\"\n log += \"latitude=\" + worldMap[1]\n log += \"&longitude=\"\n log += worldMap[0] \n log += \"&zone=\"\n log += utmZoneHemisphere + \"&color=black\"\n console.log(log)\n \n return html`${svg}`\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":2,"value":"html`

`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":865,"value":"md`\n# Test using known values\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":872,"value":"md`\nTo assist in confirming that the installation of the new \ncoefficient file is correct we provide a set of test \nvalues in this package. Here are a few as an example:\n\n~~~\nDate HAE Lat Long Decl Incl H X Y Z F Ddot Idot Hdot Xdot Ydot Zdot Fdot\n2020.0 66 14 143 0.12 13.08 34916.9 34916.8 70.2 8114.9 35847.5 -0.1 -0.1 29.6 29.6 -41.4 -46.4 18.3\n2020.0 18 0 21 1.05 -26.46 29316.1 29311.2 536.0 -14589.0 32745.6 0.1 0.1 0.0 -0.9 51.2 54.5 -24.3\n2020.5 6 -36 -137 20.16 -52.21 25511.4 23948.6 8791.9 -32897.6 41630.3 0.0 0.0 -21.6 -21.6 -3.8 65.4 -64.9\n2020.5 63 26 81 0.43 40.84 34738.7 34737.7 259.2 30023.4 45914.9 0.0 0.1 5.9 5.9 2.4 128.2 88.3\n\n~~~\nWhere HAE is height above WGS-84 ellipsoid.\n\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":883,"value":"$33","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":909,"value":"test = [\ngeoMag( 14, 143, 66, new Date(2020, 1, 1)),\ngeoMag( 0, 21, 18, new Date(2020, 1, 1)),\ngeoMag(-36, -137, 6, new Date(2020, 6, 1)),\ngeoMag( 26, 81, 63, new Date(2020, 6, 1)),\ngeoMag( 14, 143, 66, new Date(2020, 1, 1)),\ngeoMag( 0, 21, 18, new Date(2020, 1, 1)),\ngeoMag(-36, -137, 6, new Date(2020, 6, 1)),\ngeoMag( 26, 81, 63, new Date(2020, 6, 1)),\ngeoMag( 89, -121, 28, new Date(2020, 1, 1)),\ngeoMag( 80, -96, 48, new Date(2020, 1, 1)),\ngeoMag( 82, 87, 54, new Date(2020, 1, 1)),\ngeoMag( 43, 93, 65, new Date(2020, 1, 1)),\ngeoMag(-33, 109, 51, new Date(2020, 1, 1)),\ngeoMag(-59, -8, 39, new Date(2020, 1, 1)),\ngeoMag(-50, -103, 3, new Date(2020, 1, 1)),\ngeoMag(-29, -110, 94, new Date(2020, 1, 1)),\ngeoMag( 14, 143, 66, new Date(2020, 1, 1)),\ngeoMag( 0, 21, 18, new Date(2020, 1, 1))\n]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":6,"value":"md`## Imports & Libraries`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":46,"value":"import {checkbox, color, select, slider, text, usaMapCoordinates, worldMapCoordinates} from \"@jashkenas/inputs\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":8,"value":"import {requireFromGithub } from \"@bumbeishvili/fetcher\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":322,"value":"md`## margin-info\nhttps://github.com/spatialillusions/margin-info`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":14,"value":"griddeclinationdiagram = requireFromGithub(\"https://raw.githubusercontent.com/roblabs/margin-info/master/dist/griddeclinationdiagram.js\", \"griddeclinationdiagram\") ","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":11,"value":"scalebar = requireFromGithub(\"https://raw.githubusercontent.com/roblabs/margin-info/master/dist/scalebar.js\", \"scalebar\") ","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":16,"value":"slopeguide = requireFromGithub(\"https://raw.githubusercontent.com/roblabs/margin-info/master/dist/slopeguide.js\", \"slopeguide\") ","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":352,"value":"$34","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":329,"value":"geoMagFactory = requireFromGithub(\"https://raw.githubusercontent.com/cmweiss/geomagJS/master/geomag.js\", \"geoMagFactory\") ","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":373,"value":"geoMag = geoMagFactory(WMM)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":998,"value":"md`## Geodesy`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1245,"value":"// See discussion here on how to pull in the Geodesy library\n// * https://talk.observablehq.com/t/using-import-with-esm-module-exporting-a-default-class-fails/889\n// * https://observablehq.com/@observablehq/module-require-debugger\ngeodesy = (await import(\"https://unpkg.com/geodesy@2.2.0/utm.js\"))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1247,"value":" utmCoord = new geodesy.LatLon(worldMap[1], worldMap[0]).toUtm()","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1105,"value":"Mgrs = (await import(\"https://unpkg.com/geodesy@2.2.0/mgrs.js\")).default","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1230,"value":"md`\n

\nFor the (Lat, Long) of (${worldMap[0]}, ${worldMap[1]})\nTrue North for this coordinate in UTM zone = ${utmCoord.zone}${utmCoord.hemisphere}, convergence = ${utmCoord.convergence}°\nMagnetic Variation from True North according to WMM = ${geoMag( worldMap[1], worldMap[0], 0, new Date()).dec}°\nMagnetic Variation from Grid North = (utmCoord.convergence + magneticVariation) = ${geoMag( worldMap[1], worldMap[0], 0, new Date()).dec + utmCoord.convergence}°\n

\n`","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1100,"value":"mgrs = Mgrs.parse('33V VE 72202 87839');","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1153,"value":"mgrs.toUtm().toString()","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1121,"value":"mgrs.toUtm().toLatLon();","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1218,"value":"mgrs.toUtm().toLatLon().convergence","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1134,"value":"new geodesy.LatLon( 48.8583, 2.2945).toString()","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":1151,"value":"new geodesy.LatLon( 48.8583, 2.2945).toString('dms')","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"}],"files":"$W35","stdlib":"1","titling":"auto"}} 30:"$2f:body"