top | item 44808480 Trig Spiders from Mars 2 points| drsim | 6 months ago |alasdairrae.github.io 2 comments order hn newest lhmiles|6 months ago What are the dots? drsim|6 months ago Physical triangulation stations (trig points) for surveying and mapping.
lhmiles|6 months ago What are the dots? drsim|6 months ago Physical triangulation stations (trig points) for surveying and mapping.
lhmiles|6 months ago
drsim|6 months ago