GRIDFINDER
GRIDFINDER INSTRUCTIONS
You must enter your Latitude-Longitude pair in only one of the four options listed. When you have done so, click your mouse on "Find C.A.P. Grids."
You can get the Latitude-Longitude pair from any source, but GridFinder™ is designed around SARSAT hits.
Option 1: You must enter the Latitude and Longitude in WHOLE Degrees and Minutes with decimal minutes. Example: 44 in the degrees (º) block, then 59.34 in the Minutes (') North (N) block. LONGITUDE is entered in the same way. Example: 92º 44.82' West (W). DO NOT ENTER A LEADING ZERO! ALSO, YOU MAY NOT ENTER ZERO MINUTES!
Option 2: In this option you enter the Latitude and Longitude in Degrees with decimals (DEGREES.deg). Example: Latitude 44.989º N and Longitude 92.747º W.
Option 3: If you choose this format you must enter Latitude and Longitude in whole Degrees, whole Minutes, and Seconds with a decimal afterwards (if desired or needed). Example: Latitude 44º, 59' (whole minutes) 20.4'' (decimal seconds) N and Longitude 92º 44' 49.2''W. YOU MAY NOT ENTER ZERO MINUTES OR ZERO SECONDS!
Option 4: This is similar to option 2, except instead of using West Longitude we use a minus sign-to the left, or West, of the Prime Meridian (0º Longitude) being negative. For the Western Hemisphere, the area of the Earth that GridFinder™ covers, simply take the West Longitude and add a minus sign to get the equivalent. In any case, enter the Latitude and Negative Longitude in Degrees with decimals. Example: 44.989º N Longitude -92.747º DO NOT RE-ENTER THE MINUS SIGN, AS IT IS ALREADY THERE!
All Options: With this small menu you can determine which things you want to include or eliminate from your final output box, in other words, your OPTIONAL OUTPUT. If the square next to "Maps" has a check in it (which is the default) you will view four maps of increasingly larger scale for the point you select. This option requires a connection to the internet to function properly. The next check box is for the simplified Grid Diagram. This option will output a simplified grid chart of the entire Sectional with the grid that contains your point being highlighted in red. This feature is optional because in older web browsers such as Microsoft Internet Explorer 3.0, it might take a minute or so to display the diagram. The last check box option is "No Extras & Offline." You can check this if you don't want to see any of the internet links, maps, or even the grid diagram. Note, however, that even if your computer is NOT connected to the internet when your links are generated by GridFinder™, you can connect to the internet at a later time and click on the link to navigate to that desired feature.
Feel free to play around with GridFinder™. You really can't hurt anything!
GRIDFINDER FAQs
- 1. (Q) Is GridFinder™ available as a zipped download for installation on a local machine instead of having to connect to the internet?
(A) GridFinder™ can do this right now! All you have to do is go back to the data input screen and right-click on any blank part of the screen. Then choose "save as" or "save frame as," whichever your web browser has. Then save the file somewhere you can find again later. Now type the DOS-style address into the window on your web browser (such as Internet Explorer or Netscape). For example, if you saved the file in your "temp" directory, you could type in: C:\temp\gridfinder.html and your web browser should find the file. If this doesn't help, just ask!
- 2. (Q) After typing in the coordinates and hitting the "Find CAP Grids" button, a message comes up reading "Error has occurred in the script on this page." I have tried all of the combinations and nothing I do will let me open the page after entering the coordinates. I have used AOL upgrades 5 and 6. What is wrong?
(A) The reason why this error occurs is unclear. The application has been thoroughly tested using Microsoft's Internet Explorer (versions 3.0 and later) and Netscape's Navigator (4.0+). My suspicion would be that it is actually a problem with America Online's web browser. If it does not allow Javascript 1.2 or later to be run correctly, that might be the cause of the problem.
- 3. (Q) I can't seem to get your gridfinder to accept any latitude-longitude points I enter. I keep getting a message that the points are invalid. What am I missing? I've tried all formats with no luck.
(A) While I would need more information to be sure, my suspicion is that you might be leaving one or more blocks blank or with a "0" (that's zero) in them. If you use a zero for your minutes but enter seconds, for example, the computer will think you made an error when inputting points. You can test the program by entering coordinates EXACTLY as listed in the examples right above the blocks. Please let me know what version of Netscape or Internet Explorer you are using if you still have trouble. I'm committed to working the problems out!!
Features of Grid Finder™ version 4.0
- GridFinder™ 3.0e and later includes a database of Airports & NAVAIDs (in addition to the AFRCC Crash Sites) included on the maps. The key to the map items is as follows:
- The SARSAT HIT should be at the center of the map
- A publicly registered Airport as identified by its 3 letter identifier
- An AFRCC historical crash site
- An NDB as identified by its call letters
- A VOR station (without DME) as identified by its 3 letter callsign
- A VOR/DME station as identified by its 3 letter callsign
- If the icons are nearly on top of one another, the computer may separate them. Try using one of the more zoomed-in maps for a better idea of the layout of everything.
- PLEASE NOTE that there is no way to ensure this database is updated. DO NOT USE these maps for navigation.
- GridFinder 3.0c and later includes a cool little graphic in the NSWE sectional border table that adds emphasis, clarity, and elegance to this section of the output.
- GridFinder versions 3.0b and later now include the AFRCC Crash Locator Database! You don't need to do anything to access the database, existing crash sites will automatically appear plotted on your map as a red bulls eye with supplemental information as the label. For clarity's sake, the sites are only plotted on the 1x1 degree and larger scale (smaller area) maps.
- GridFinder 3.0e and later fixes a display problem with the East-West Sectional Borders. Earlier versions had an error on the sectional information page that pops up after inputting the lat-long: the sectional boundary information did not display correctly. It showed the east/west boundaries as the same number while the north/south have always been correct.
- While GridFinder does provide some new technology to Civil Air Patrol users, even more it congregates available technology into one location. Mission Coordinators and others should find the features of GridFinder™ useful in dispatching Emergency Services air and ground crews.
- When you give the program a Latitude-Longitude (lat-long) Coordinate, it will compute and show you a CAP search grid using the Cell (new) grid system. This eliminates the need for plotting SARSAT hits on a map solely for the purposes of locating a grid. Aircrews can be dispatched to a Cell Grid more quickly than to a specific lat-long coordinate.
- Error Checking: if you enter an invalid parameter, such as a latitude greater than 90º, a longitude greater than 180º, or any value in minutes greater than or equal 60 (the next degree), the application SHOULD either not execute or give you an error. If your coordinate lands exactly on the boundary (e.g., 30') the computer will default to the grid quadrant immediately to the NORTH and or WEST of that border/coordinate. This is consistent with the system since all grids are to the Northwest of the original reference point.
- You will see both the 15 Minute Cell Grid and the 7.5 Minute (subdivided) Cell Grid. The Cell grid system works anywhere in the Western half of the Northern Hemisphere (Northwestern Quadrant). All of North America is therefore covered by this system. The output of this program will issue both the standard 15-minute by 15-minute grid AND the 7.5-minute by 7.5-minute grid applicable to the selected set of coordinates. Users of the Cell (new) grid system and this application should be familiar with The Cell (new) CAP Grid System and/or can view this document for self-training and/or clarification.
- It will also show you the C.A.P. Grid Number using the Conventional (old) grid system.
- It will give you the subdivided (A-B-C-D) 7.5-Minute Conventional Grid.
- The program will tell you which (primary) Sectional Chart contains the coordinate pair and how many Conventional grid squares that sectional contains. Versions of GridFinder™ v2.3 Beta and later fully support overlapping Continental United States (CONUS) Sectionals. The Denver-Albuquerque, Kansas City-St Louis, St Louis-Cincinnatti, Cincinnati, Atlanta-Charlotte, Los Angeles-Phoenix, and Los Angeles-Las Vegas overlaps are supported. Note that the Sectional Chart to the North and West is considered the Primary chart.
- You may input the lat-long coordinates in one of four widely recognized formats. This is useful in when using different types of GPS equipment that utilize differing coordinate formats.
- Degrees with Decimal Minutes
- Decimal Degrees only
- Degrees and Minutes with Decimal Seconds
- Negative Longitude Format: Version 2.8 and up of GF2K now corrects for a fundamental error in the computation of "negative" format latitude-longitude coordinate pairs. To mentally convert from West Longitude to positive-negative longitude, you can simply think to add a negative sign instead of using "West."
- Grid Finder 2000™ will convert the format you gave into the other three remaining formats; this is useful if your GPS, LORAN, moving map, or other equipment utilizes a format that is different than the original.
- If you use United States Geological Survey (USGS) topographic maps, the 7.5-minute by 7.5 minute quadrangle will likely interest you. Versions 2.9 and later include the USGS map index number for the point.
- An automated table will be generated that represents the appropriate sectional chart. The grid that contains the coordinate will be highlighted in blue. WARNING! It may take up to a minute, or even longer, for the Grid Diagram to appear. You may get a screen flicker while this occurs. Be patient and you will be rewarded.
- In preparation for future functions, Versions 2.9.6 and above have a semi-streamlined input interface. It is simpler and the first-time user can understand how to input the relevant information more quickly.
- You can now (v 2.9.8+) print the results of Grid Finder 2000™ simply by clicking on the "print this page" button. This feature is not supported by older versions (3.0 and earlier) of Microsoft Internet Explorer.
- In previous versions, if your point was exactly on a border of a Conventional Grid (every 15' or .25 degrees of latitude and/or longitude), GridFinder™ was confused. Now if you land exactly on a border of a Conventional Grid, the program will give you the grid number to the North and/or West (upper left) of that border.
- Previous versions will occasionally mangle, due to rounding error(s), the conversions between formats within an error of one minute. For example, if you entered 32.1 deg N 115.1 deg W you get an erroneous output (in the first set ONLY) of 32º 6' 0"N 115º 5' 0"W, which should be 115º 6' 0"W. It only seemed to mangle the Longitude--in any case, this error is believed to be FIXED. Please report anything to the contrary at the address below.
- Version 3.0+ changes eliminates extraneous output such as the 7.5 minute letter when that parameter is unavailable or does not make sense.
- Version 3.0 and later adds grid boundaries (North, South, West, East) to the Sectional Information section.
- Version 3.0 and beyond have a help and information page that is separate from the data entry page. This allows for uncluttered appearance, smaller download size, and overall easier operation. Links are provided to the appropriate sections from the data input screen.
- Version 3.0+ has the Canadian-style search grid, as described in the Canadian SAR Manual. One may also derive the GEOREF location (within 7.5') of the point with this grid style.
- Version 3.0 now supports Alaskan series of NOAA/NOCA Sectional Aeronautical Charts. There are not yet expanded grid diagrams for these sectionals, but the abbreviated ones can be viewed. Note that due to the small distance between lines of longitude that these grids will be very small and that a particular sectional may contain more than 1,000 grids. This is compounded by the fact that Alaska is a VERY large place. For the extreme Western Aleutian Islands in Alaska (that is, West of the 180º longitude) you will need to enter your data in WEST longitude. For example, 178º East Longitude must be entered as 182º West Longitude.
- Version 3.0.1 fixes the leading zero error. That is, previously if a user input "092" as the longitude, the computer would read that as "09." Now leading zeros are accepted.
- Version 3.0.1 fixes the intermediate zero error. Previously, if you entered a zero for any intermediate point, for example, 45º 0' 12", the computer will think you left that block blank and gave you an error. You may now enter intermediate zeros.
- Version 2.9.9 and later have an "No Extras & Offline" check box available. Checking it will restrict the output and not print any online features. The only feature you need to be connected to the internet for when you click "Find CAP Grids" is the "Maps" option (default). Remember that even if your computer is NOT connected to the internet when your links are generated by GridFinder™, you can connect to the internet at a later time and click on the link to navigate to that desired feature.
- If you save this page as an .html document and refer to it later in your web browser, you will be able to get the program to run with the features listed above. This is called "client-side" processing and it allows you to use this application even though you are offline (not connected to the internet). This feature allows you to utilize this program on-the-fly, such as on a laptop in a mobile or austere mission base situation. The following features, however, are only available if your computer is connected to the internet (online).
- Version 2.9 and later integrate a map-plotting function in 4 different scales. You will need to be connected to the internet, however, for the automated map system to work. The maps feature may appear as broken-picture links if you are offline. Additionally, the U.S. Census Bureau's Tiger Mapping Server, or TMS, must be up and operational. If it isn't, email them and ask them to get it back online. If it is working, email them and ask them to continue their wonderful support. In any case, the maps you will see are:
- 10 by 10 Degree Quadrangle: Multiple-State View
- 1 by 1 Degree Quad: Locality View
- 0.5 by 0.5 Degree Quad: Local Area View
- 0.1 by 0.1 Degree Quad: Detail Street View
- Grid Finder 2000™ versions 2.9.3 and later provide links to additional features.
- The point you selected can be viewed on a Sectional Aeronautical chart via MapTech. This site will center the map at the Lat-Long coordinate given. This site does not mark the coordinate pair on the map. You may access additional features from that site using the browser window that it opens in.
- Imagery (aerial photographs) of the coordinate point can be retrieved via the link to MicroSoft's Terraserver project. The site will initially display a small topographic-type map of the area of interest. This site does not mark the coordinate pair on the map. You may access additional features from that site using the browser window that it opens in. Specifically, you will want to look to the right of the map to view the list of available overhead imagery (photographs), if they are available. Imagery exists in at LEAST one format (USGS orthophoto and/or SPOT imagery) for most parts of the Continental United States.
- The TopoZone link will display a 1:25,000 scale USGS topographic chart with excellent detail. TopoZone will display a small red cross at the coordinate pair.
- The link to the diagram of the Conventionally Gridded Sectional is described below. Requires a connection to the internet.
- Versions 2.9.4 and later incorporate a selective-output feature that allows the user to tailor the output (somewhat) to greater or lesser degrees. Specifically, it allows the user to 1) cut down the computer's display time for the sometimes-lengthy grid diagram by allowing it to be eliminated and 2) allows the user to eliminate the broken-picture-link symbols when not working online.
- A link to a diagram of the Conventionally Gridded Sectional is available in versions 2.9.5 and later. This link is available regardless of whether or not the user chooses to see the "grid diagram," and displays greater detail (specifically, it shows the cardinal lat-long degrees) and graphical depictions of Sectional Chart overlaps. The diagram does not provide these features, but does highlight the Conventional grid of interest.
- A link is provided to NASA's real-time tracking of SARSAT-COSPAS satellites. You can now know when the next pass will be by watching it on your computer! Initially loading the tracker requires a connection to the internet, but if you leave the window open you can go offline and the tracker will still predict the location of the satellites. Please don't use this tool to pester AFRCC--they'll get you your updated hits as soon as they can.
- When the point is located on a border, GridFinder™ defaults to the grid immediately to the North and West of that point. Future versions may include additional options, but for now that is our convention
Known Problems with this version:
efforts are underway to resolve these problems but you can avoid them with knowledge.
GridFinder™ works best when you don't try to fool it. That is, if you enter points outside of the continental United States you won't get complete results. If the information that you enter is incomplete you may be required to reenter it. You should not mix coordinate data types; you may get an erroneous result with no error indication.
For an unknown reason, GridFinder 2000 will sometimes very occasionally give an erroneous "Javascript Error." This is a problem with your Web Browser and most often occurs with MS Internet Explorer. To work around the problem, execute the script again by pressing "Calculate CAP Grids." If you get the error again, try closing the output window and THEN re-executing the program.
There are two requirements to run GridFinder™. If you don't meet either one you should see a message similar to the two requirements below on your screen on the data entry page.
1) You need a web browser that is capable of JavaScript 1.2 or higher (Microsoft Internet Explorer 3.0+ or Netscape 3.0+). Update you web browser with a free download from Netscape or Microsoft.
AND / OR
2) You need to enable Javascript using your web browser options and/or preferences. Refer to your software's help file for specifics.
Please report any additional problems via the webmaster below. If this help file was not helpful, we need to know that as well!
Contact Major Scott E. Lanis, Civil Air Patrol, with comments, submissions, questions, or for more information about this applet. This is hosted by the Wright Brothers 282nd Aero Composite Squadron as a mirror service.