> After pouring over many word/phrase searches for "scalable grid overlay," "adjustable square grid for Google maps," and every other conceivable combination, I am just about ready to give up! Maybe some of you here can point me to help...or the edge of a cliff!
This was mentioned in several posts in this group: http://www.bdcc.co.uk/Gmaps/ll_grat_v3_demo.htm (disclaimer: I haven't used it myself). Additionally, if you search this list you will find other ways of solving this ( raster images with transparency, poly lines, accessing another service and adding it as a layer, etc.). > Here is what I want to do. Some details first.> -I am in the agriculture industry. We grow many thousands of acres of vegetables that are consumed in the US. Okay ... 'large 'area' .... consumed in the US, but *where* are they growing? ( affects which imagery you might have available). > >-We plant all these vegetables on a daily basis on any number of our > different parcels throughout the county.-In, say, a field (parcel) that is > 45 acres, we may plant on day one 6 acres of Iceberg Lettuce. Next day, > 2.5, and so on. > So the temporal interval is most likely fairly short .... >-In reality, we would like a means to use an ipad or computer to access Google maps to select and zoom in to the parcel that was planted and then using the measurement tool, measure (as closely as possible), how many acres were planted on a particular planting. Field mobility (literally :-) Which means you may need to consider what happens if the connection is intermittent. And depending where you are in the world, have you considered that the *projection used in Google Earth<http://blog.perrygeo.net/2005/12/11/tissot-indicatrix-examining-the-distortion-of-2d-maps/> * will affect your area / distance calculations? > Here is the problem. I can do this now but it dose not do what we really > need. > Of course it doesn't - to some extent you are using a pile driver to plant peas. > What I really need is some way to create a grid that can be overlaid over Google maps that is of a particular scale. For many crops such as romaine, lettuce, and cabbage for example, we plant the crops on beds that are 3.5 feet from bed top center to bed top center. And for other crops like spring mix or spinach, we plant crops on beds that are 7 feet from bed top center to bed top center. Micro level scale, okay. > So in this case, I need two grids: one that is 42 inches wide and another that is 84 inches wide. I can take this grid now, place it over my field, and can now estimate how many beds were planted, should be planted, etc. The other issue, though, is the smallest zoom level in GM is 200ft and so that will make the beds (grid) very small. Is there a way to increase the zoom beyond this 200 ft? Hypothetically, 'yes', using custom layers and an external web service, et<https://developers.google.com/maps/documentation/javascript/maxzoom>c.. > This may be difficult to understand. Sorry about that. Ideas? It is actually very understandable. But, while Google Maps is a very cool tool, you have probably reached the limit for what it can do for task ( basically precision agriculture), It works on larger scales,and you are at the mercy of their provided imagery., and especially since you will eventually expand your capabilities. My recommendation is (if cost is a factor) is to use some FOSS GIS application to prepare and analyze your data ( I use Quantum GIS <http://www.qgis.org/>, part of the OSgeo<http://www.osgeo.org/>technology stack ). Then you connect to various Web Mapping Services like the USDA's http://droughtmonitor.unl.edu/dmshps_archive.htm and http://www.fsa.usda.gov/FSA/apfoapp?area=home&subject=prog&topic=landing , (and there are lot's more, depending on the country you are in. Hwile you are experimenting, you can upload directly to http://qgiscloud.com/ . You could also then spin printed data products, if needed or download digital ones for disconnected devices in the field. There is some effort to port to Android, etc., but I'm not all that familiar with that. Michael Fell free to contact me off-list, since at this point it probably diverges from the API. > > -- You received this message because you are subscribed to the Google Groups "Google Maps API V2" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-maps-api/-/I3m2J04C4OMJ. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-maps-api?hl=en.
