Questions and answers
Scenes
Section titled “Scenes”I marked a scene for download, but it is not on the main map.
Section titled “I marked a scene for download, but it is not on the main map.”A marked scene waits until an administrator processes the queue (The download queue); the scenes are then processed one after another, several minutes each, and the queue page shows how far the run has gone. Its status in the catalog tells you how far it has gone (Processing statuses). It reaches the main map once its status is Slippy Maps Generated or Completed: reload the main map then. A status with Failed in it means processing stopped: mark the scene again, or ask an administrator.
The catalog has newer scenes than the main map.
Section titled “The catalog has newer scenes than the main map.”The catalog lists every scene the satellites took; the main map shows only those that have been processed. Mark the newer scene for download if you want it on the map.
The catalog says a scene has 5 % cloud, but the main map says 60 %.
Section titled “The catalog says a scene has 5 % cloud, but the main map says 60 %.”They measure different things. The catalog’s figure is the satellite’s own estimate for its whole tile, an area about 110 km across. The main map’s is the cloud over your fields, from the scene’s own cloud and shadow masks. A tile that is clear overall can be cloudy right over your fields, and the other way round.
Why is a day missing from the timeline?
Section titled “Why is a day missing from the timeline?”Either no satellite passed that day, or the scene was not processed. The catalog shows every pass (The satellite catalog).
What is a monthly composite, and when does one appear?
Section titled “What is a monthly composite, and when does one appear?”A picture built from every usable scene of one month, keeping each spot’s clearest pixel (The words this guide uses). It is built after its month has ended, so the latest month appears some days into the next. Composites have their own lane on the timeline, Monthly. Groups with quarterly composites also get one for each finished calendar quarter, in the Quarterly lane, about a week after the quarter ends.
Values
Section titled “Values”A field has no value in a scene.
Section titled “A field has no value in a scene.”Usually cloud: when too little of the field could be seen, there is nothing to measure. The field’s dot in the fields panel shows how cloudy it was. A field added after the scene was processed has no value in it either, and neither does a field at the edge of a scene that does not cover it.
Sentinel-2 and Landsat give different values for the same field.
Section titled “Sentinel-2 and Landsat give different values for the same field.”They see slightly different colours, at different pixel sizes (10 m against 30 m), and on different days. Compare a field’s values within one satellite; the chart can show them apart (The chart).
The status strip shows a range, such as 0.40 to 0.50, not a number.
Section titled “The status strip shows a range, such as 0.40 to 0.50, not a number.”It reads the colour of the map, and each colour stands for a range of values (Reading a value). For a field’s exact figures, use the fields panel and the chart; for every pixel’s value, download the layer as a GeoTIFF (Downloads).
A field’s value dropped for one scene, then came back.
Section titled “A field’s value dropped for one scene, then came back.”Look at that scene in True Color: a thin cloud, haze or a shadow the mask missed can pull the value down for one day. Turn on Skip over 50 % cloud in the chart to leave the cloudy scenes out.
The map
Section titled “The map”Part of the map is grey or empty.
Section titled “Part of the map is grey or empty.”The scene does not cover that area, or it was not processed there: a group’s scenes are processed for the area around its fields and boundaries only. Zooming very far in or out can also show no tiles: zoom back to the fields.
I cannot find a field on the map.
Section titled “I cannot find a field on the map.”Type its name in the search box in the top bar, or in Search fields in the fields panel, and choose it: the map moves to it.
How do I show a colleague what I am looking at?
Section titled “How do I show a colleague what I am looking at?”Press the share button in the top bar and send them the link (Sharing a view). They need access to the same group.
Alerts
Section titled “Alerts”An alert came after a cloudy day.
Section titled “An alert came after a cloudy day.”Open it, and look at its cloud badge and at the scenes in the player (Triage on the map). If the drop was the cloud, mark it False positive.
The same place has an alert in several indices.
Section titled “The same place has an alert in several indices.”Each index that fell raises its own alert, and the table shows them together on one row. Acting on the row acts on all of them.
Your account
Section titled “Your account”I have forgotten my password.
Section titled “I have forgotten my password.”Ask an administrator to set your account up again with a new first password, then change it yourself (Changing your password).
I cannot see a group I need, or a page says Access denied.
Section titled “I cannot see a group I need, or a page says Access denied.”Each person sees only the groups an administrator has given them. Ask one to add the group to your account.
Who can see my group’s fields and alerts?
Section titled “Who can see my group’s fields and alerts?”Only the people given that group, and the site’s administrators.