Leveling Online Computations User Service

Output Files

LOCUS produces two output files, *.adj and *.ph1, both in ASCII text format. Note that these files may not appear correctly formatted if opened using Microsoft Notepad, but will appear correct using other text editors (e.g., WordPad, TextPad, etc.). These files are named the same as the .hgz file the user uploaded and are compressed and available in “userfile”.zip. Userfile.adj is the complete adjustment report. Userfile.ph1, which NGS calls the “phase one”, has unadjusted heights and other information. The section of the .adj file with adjusted geopotential numbers and orthometric heights (elevations) is displayed on the screen after LOCUS has run. The main sections of the output files are briefly described below.

"Userfile".adj. This is the main output file users will refer to. The input file name, datum, and constraints are shown as the user selected them when setting up the LOCUS run.

The following test values of the statistics, if exceeded, cause an asterisk (*) to be written in the Adjustment statistics section later in the report: 

38:Flag Norm 2.50
39:Flag V 5.00 (mm)

Adjusted values (example below): 1. Geopotential (geopotential numbers, units of kgal-m) These quantities are determined from input orthometric heights and gravity values, then adjusted. 2. Elevation (Orthometric heights, units of m). These quantities are derived from the adjusted geopotential numbers using the gravity values. Differences between these adjusted heights can be compared against differences between heights published on NGS datasheets for evaluating a two- or three-mark tie.

Line/Part:  L26771                     SSN*:  mark constrained
Mark ID   SSN    PID   Designation  Geopotential   Elevation      Codes
   0     1037*  QP0857  2180 J        406.77434    414.82070 (m)
   1     1036   QP0858  2180 H        419.64711    427.94752
   2     1001*  QP0862  2180 G        404.89534    412.90390
   3     1002   DG9889  URNESS        402.92006    410.88937

Adjustment statistics (example below): Any residual value over 5 mm in this section has an asterisk (*) which indicates an observation that does not fit as expected and / or a mark that may have moved. The Norm (normalized residual) column (farther to the right, not shown here) is an additional statistical indicator which, if flagged by *, indicates potential problems with the new observations, the existing network, or both. 

Mark IDs            from   to                           Geopotential    Sigma     Residual Stats
from to   Line/Part SSN   SSN  Runs   km    Year   OC  Difference   Prior Post      V      Norm
  2    3  L26771    1001* 1002   2   1.01   2005   21     -1.97799    1.5  0.9     14.91*  10.40*
  3    4  L26771    1002  1004*  2   0.62   2005   21      9.70967    1.1  0.9      9.19*   8.17*
----------------------------------------------------------------

"Userfile".ph1: “phase one” file, displays the starting height, positions, distances along the line, spur lines, and observed heights with corrections applied (all those available, except the orthometric correction). Differences between the phase one observed heights can be compared against field differences from older surveys of the same marks.

side image