Idividual questions herein can be referenced using their tags like: terrafly.com/geoquery.FAQ.html#Metadata
Datasets: How do we choose a dataset?
A: terrafly.com/geoquery.manual.html#category
Number-of-records: How many records are returned by the query?
A: There is a default that can be overwritten with "numfind=...", see terrafly.com/geoquery.manual.html#numfind
Limiting-Radius: How do we limit radius of the records to be retrieved?
A: The default radius is normally infinite -- we retrieve a limited number of matching records nearest to the given point, even if the nearest matching record is on another continent. This, however, can be user-constrained to a radius using the "d=" parameter, see terrafly.com/geoquery.manual.html#distance
Radius: What is the radius of the records returned to a query?
A: The semantics of the http2xml GeoQuery is "for a given point and criteria, get the records complying with the criteria and sorted by distance to the point". The user can override defaults for the maximum number of records to return (numfind=) and maximum distance (d=).
Metadata: What is the meaning and format of each field in the dataset?
A: Your datafeed portal page is subdivided into sections headed by the dataset title in red. The first link under every such red title is to the metadata, including descriptions of all columns.
CSV-coordinates: Why in the CSV file lat&long appear in the last columns and again elsewhere?
A: This is in fact redundant
Distance+Offset: What are the offset and compass directions columns?
A: The distance, offset and compass direction attributes are computed in real time, calculated by the difference between the record's latitude and longitude, and the query (URL) latitude and longitude:
| lat | Latitude of the location of this object |
| lon | Longitude of the location of this object |
| distance | Distance in meters of the location of this object from the reference point |
| compass_direction | Compass direction (N W E S NW NE SW SE) towards the location of this object from the reference point |
| offset | Normally not computed, but may be computed as the angular difference in degrees between the approximate discrete compass_direction and the exact numeric compass direction |
Search-nearby: Does GeoQuery returns the records of the nearby areas if there is no data at the given coordinates?
A: Yes
Coordinates-in-XML: Where in XML files do I find coordinates of the resultant records?
A: In fields “lat” and “lon” at the end of the record.