Below are detailed instructions for how to use ArcGIS collector on an iPad in offline mode to collect field data on a grid of determined cell size (20x20m) overlaid on a base map of high resolution imagery. Forms are set up to have drop down menus and time stamps are automatically recorded.
The main steps are:
- Create the grid as a matrix of rectangular polygons and save it as a shape file.
- Edit the attribute table of the shape file to contain the appropriate fields for entry, including codes and drop downs.
- Create an online web map with the to hold the data
- Download the web map to the iPad, configure and enter data, then sync.
Details are outlined in this pdf.