Compare View is a fast and convenient way to compare time-series surveys and monitor for change over time, look for weak signals or report about a work-in-progress situation. Three modes of comparison are available :
- Overlay
- Slide
- Split
From a Site that contains at least 2 distinct surveys from same geographical area of interest, select first Compare from the right side :
NB : Compare is disabled if Site has not enough data.
1. Selecting surveys & models to compare
Select views mode, top layer, bottom layer, and the categories of layers to be compared from the existing layers in project (orthomaps, DSMs) :
2. Compare / Overlay
This mode overlays two layers (orthomaps, DSMs, NDVI) at same position. Visual examination for differences can be eased by adjusting Top Layer opacity using slider bar:
3. Compare / Slide
The Slide View allows to swipe between two layers side by side for the difference examination, which is particularly useful to check for absence or presence of items, or examine variations in terrain surface from DSMs.
4. Compare / Split
The Split View enables to compare two layers side by side without overlaying :
Read here more about doing a thorough comparison based on DSMs, using the Change Map analytic.