Guides
How to read the files, and how to size the survey.
Each guide answers one question, from a file or a dataset the lab actually holds. The samples are copied byte for byte, and every number traces to the file, the datasheet, or a script that regenerates it.
Reading a file
-
Reading a RINEX observation file
A RINEX 3.03 observation file annotated field by field, from a static occupation on campus. What each header record means, how epoch and observation records are laid out, and how to decode codes like C1C and S1C.
Read the guide → -
Reading a CSRS-PPP report
What every block of NRCan's output means, read off the same occupation: the a priori and estimated coordinates, the 95 % sigmas, the reference frame and its epoch, and the rows that carry the answer.
Read the guide → -
Reading a LAS/LAZ header, and what COPC adds
A LAS header from two real point clouds, byte by byte: version, point format, scale and offset, bounds, and the record that carries the coordinate system. Then the same cloud as COPC, and what the index buys.
Read the guide →
Estimating before you collect
-
How long to occupy a GNSS point
How long a static occupation needs to be, measured epoch by epoch on a two-hour campus run: where the uncertainty falls fastest, where it stops paying, and why height converges last.
Read the guide → -
How point density falls off with distance from a laser scanner
Density falls as 1/r² on a surface facing the scanner, as 1/d³ on flat ground once grazing incidence is counted, and faster still in forest. Two lab survey-planning studies, and what each leaves out.
Read the guide → -
Calculating point density for a UAV lidar survey
Points per square meter on the ground from a sensor's stated rate, altitude and speed: the projection term most napkin calculations drop, a worked example, and how far the delivered rate sits below the spec.
Read the guide →
Working with the lab
The lab collects, processes and publishes the data these guides are written from, and runs the surveys they help plan.