U.S. Census Bureau: locate an address
For street-address input, LotProfile uses the Census Geocoder. Census documentation says matches are derived from MAF/TIGER address ranges and coordinates are interpolated or approximated. Address ranges can contain possible numbers where no structure exists.
Implication: a match is a useful analysis point. It is not proof of a building, parcel centroid, surveyed corner, or ownership boundary.
USDA NRCS: identify mapped soil context
LotProfile queries Soil Data Access for SSURGO map-unit and component records at the analysis point. The response includes the survey area, map-unit identifiers, available aggregated fields, survey-area version dates when supplied by USDA, and retrieval time. A global dataset refresh date is not returned by this query and is reported as null; retrieval time does not mean the soil survey was updated then.
Implication: the result describes the mapped survey unit at a point. A map unit may contain multiple components, and null means no usable value was returned.
USGS: estimate nearby terrain
LotProfile requests nine elevations around the analysis point through the USGS Elevation Point Query Service and calculates a local plane. The response preserves the 3DEP dataset label, resolution reported for each sample, retrieval time, and method.
Implication: elevation and slope are planning estimates for the sampled neighborhood. They do not account for every surface or drainage feature and are not survey grade.
Failure and coverage semantics
- Address not found: Census did not return a qualifying match; the site does not silently substitute another place.
- No soil profile: no SSURGO map unit resolved at that point; this is a coverage/result condition, not evidence about the ground itself.
- Not available from this source: the requested profile succeeded but a field was null or absent.
- Source temporarily unavailable: an upstream provider failed; retrying later is more honest than inventing a value.