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· The following Table summarizes important fields in Tiger files.
Record Type | Field Name | Field Position | Description |
TLID | 6-15 | TIGER/Line ID | |
RT 1 | SIDE1 | 16 | Single side? (blank = both sides, 1 = single side) |
FRLONG | 191-200 | Start (from) longtitude | |
FRLAT | 201-209 | Start (from) latitude | |
(Basic info | TOLONG | 210-219 | End (to) longtitude |
for Lines) | TOLAT | 220-228 | End (to) latitude |
TLID | 16-25 | TIGER/Line ID (not all lines have an entry here | |
RT 2 | RTSQ | 16-18 | Record Sequence Number (1, 2, etc) |
LONG1 | 19-28 | Start (from) longtitude of point 1 | |
LAT1 | 29-37 | Start (from) latitude of point 1 | |
(Detail points | LONG2 | 28-37 | Start (from) longtitude of point 2 |
for Lines) | LAT2 | etc | etc |
RT A | |||
(Basic info | POLYID | 6-15 | Polygon ID |
for Polygons) | |||
RT I | TLID | 6-15 | TIGER/Line ID |
(Line-Polygon | POLYIDL | 27-36 | Polygon ID on the left side |
info) | POLYIDR | 42-51 | Polygon ID on the right side |
RT P | POLYID | 16-25 | Polygon ID |
(More info | POLYLONG | 26-35 | Internal Point Longtitude |
on Polygons) | POLYLAT | 36-44 | Internal Point Latitude |
Pi = 3.141592; | ||
deg = (int)x; | ||
minute = x - deg; | ||
rad(x) = PI * (deg + 5.0 * minute / 3.0 ) /180.0; |
q1 = cos( rad(x) - rad(x') ); | ||
q2 = cos( rad(y) - rad(y') ); | ||
q3 = cos( rad(y) + rad(y') ); | ||
D(p,p') = (int) (R * arccos[ 0.5*( (1.0 + q1)* q2 - (1.0 - q1)*q3 ) ] + 1.0); |
N.B. Assume points (q,f) on the equator projects to p(q,f)=(q, 0).