Questions tagged [time]

A nonspatial continuum in which events occur in apparently irreversible succession from the past through the present to the future

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27 views

Finding points in one layer within range of time of points in another layer using QGIS

I am very new to QGIS and SQL. I have two layers, each is populated with points and temporal data. One layer has information on battles occuring in Iraq and Syria, and the other has information on ...
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64 views

Time Manager on LizMap

We published a project under Ubuntu Server, QGIS, LizMap web client, .. Everything works except the "time manager". Under the desktop client, the time manager works correctly (for example ...
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27 views

Temporal Manager raster animation monthly instead of days in QGIS

I have raster files on a per month scale over several years. I struggle to create an animation that shows monthly changes. I would like to have an animation showing each monthly raster file (and my ...
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1answer
54 views

Temporally reducing image bands using Google Earth Engine

I am trying to temporally reduce an image from 365 bands (daily) to 12 bands (monthly). Context: I imported an image collection with Soil Moisture (SM) that had 8 values per day (every three hours). I ...
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1answer
50 views

Timeout while uploading large files in GeoNode / GeoServer

I am getting timeout while uploading large files in GeoNode ( System Configuration : GeoNode 3.1.0 , GeoServer 2.16.2 installed on Ubuntu 18.04. ). I tried compressing large files to decrease their ...
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1answer
30 views

How to build isochrones with GeoTools?

It is possible to compute shortest paths with GeoTools with its graph package. Is there a package (or extension) for computing isochrone lines or areas, that is the area which can be reached from a ...
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1answer
29 views

Mapping Tobler's hiking function with additional impediments using ArcGIS Desktop

Is there a way I can use Path Distance in ArcMap to calculate Tobler's Hiking Function with a DEM but also with additional time costs from non-slope impediments? For example, part of the landscape I ...
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1answer
54 views

Test intersections with time indicators in R

I have a sf object with MULTIPOLYGONS that refers to flood episodes from 1800's onwards(https://data.gov.uk/dataset/16e32c53-35a6-4d54-a111-ca09031eaaaf/recorded-flood-outlines). Then I have another ...
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38 views

How many GPS-Satellites are needed for time synchronization without positioning

Is it possible to do time synchronization without positioning with only 1 GPS satellite? If not, how many satellites do i need for time synchronization without positioning?
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1answer
115 views

Converting double values into time in QGIS's Field calculator

How can I achieve the following result (in column "output", string) in QGIS attribute table? The values in "duration" were calculated with some other formulas and represent a ...
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1answer
84 views

How to calculate Night Flight time for a given flight between 2 locations?

I am currently working on a project (web app) at university to be able to calculate the amount of time spent during night flying. Currently, I have, Departure Lat and Long and Departure Time in UTC ...
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1answer
31 views

Comparing cities polygon over time using Nightime lights [closed]

I am currently generating polygons of cities in India over time based on night light data. For this, I have been using the clump function in R and then converting them to polygons. My issue comes when ...
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1answer
161 views

Temporal controller - time-dependent symbology based on @map_start_time

I was just recently whatching Nyall Dawson's video "QGIS 3.14 time handling and map animation demo". at min 47 (nyall dawson / youtube video min 47 ) things are getting interesting from my ...
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1answer
159 views

Converting Unix epoch time to GMT time using QGIS Field Calculator

I am trying to convert the 'time' and 'updated' column from epoch to date/time GMT but I am struggling to do so. I know I have to use the field calculator tab but I am a basic at using scripting. I am ...
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1answer
50 views

Time-Based Multilateration

I'm not entirely certain, but I think this forum is most appropriate for this question. I know the location of three observers. A nearby source, who's location is unknown emits a beam of radiation at ...
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47 views

PyQGIS return Field

I have this layer: I'd like to have a label that changes in time, I have a function that gives back the current time in the same format as my field names but gives back a string, not a field. What ...
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1answer
66 views

temporal rolling mean in stars

I need to find temporal rolling means (or other stats - max, min, etc) in stars spatial obects. For stars raster cubes, this would be directly analogous to the calc(rasterBrick, function(x) movingFun(...
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1answer
106 views

PyQGIS Temporal Controller current moment

I have a QGIS Project with Temporal Controller, in Python Console. How could I capture the current moment of the simulation? I'm trying, but doesn't work canvas = iface.mapCanvas() temporal= canvas....
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14 views

Code for Extraction of pixel values post Temporal Averaging

I tried to write a code for temporal averaging the pixel values of VH polarization from Sentinel 1 collection and downloading the same as a CSV. I get an error "VH value not selected in the ...
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26 views

Get an average image, but the time of each pixel is different

Change image is an array image,he stores the time node of each pixel.time1 and time2 are the first node and the second node of each pixel, respectively.I want to get the NDSI average value of each ...
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1answer
140 views

How to add a Timeline tool to Time Lapse in GEE?

I have been struggling to add a timeline tool to a time-lapse video I put together on GEE... The last part of my code is: var polygon = ee.Geometry.Rectangle([-XX,-XX,-XX,-XX]); //xMin, yMin, xMax, ...
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Existing standard country codes explicit in time and space

There are several comprehensive systems for coding countries such as ISO, TLD, M49. I am looking for a system that is explicit about the time period that the code refers to. My application is a ...
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1answer
71 views

Convert decimal time to use in QGIS

I have a .shp file with includes a column of format Double that is the Arrival time. The time values entered are decimal time. For instance, 1 record has a decimal time of 7.11194, which converts to ...
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1answer
230 views

MODIS 'system:time_start' format problem in Google Earth Engine

In Google Earth Engine, what is the default format of time_start for MOD10A1 image?For example, var modisCollection = ee.ImageCollection('MODIS/006/MOD10A1') .filterDate('2000-08-21', '2001-02-28'...
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1answer
169 views

Buses movement data visualization in QGIS

What is the easiest way to visualize the movement of city buses in QGIS, as it is shown at this website? https://anitagraser.com/2020/05/24/movement-data-in-gis-30-synchronized-trajectory-animations-...
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1answer
53 views

Converting time in nc files

I have nc file where time unit is expressed as year and month in format "month as %Y%m.%f", type: character. For example, 199604.5 represents the year 1996, month 04. How to convert time in date ...
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31 views

How does the runtime of Haralick texture generation scale with the number of bins/gray levels? (Orfeo)

I'm trying to generate some Haralick textures of various LiDAR-derived elevation models (digital height models and digital surface models). Because the height models (DHMs) have a lower bound of 0 and ...
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25 views

How best to relate historical testing data to a shapefile?

I am tasked with bringing what has historically been only tracked in Excel into a shapefile. I am using ArcMap, but also have QGIS installed on my computer What these shapefiles will include is ...
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2answers
464 views

Converting local solar time to UTC for MODIS

I am having a hard time to convert local solar time to UTC for MODIS data. According to the Users' Guide of the product (MOD11A1 Product - Wan Z., 2013), local solar time given for each pixel is ...
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1answer
83 views

Set 'system:time_start' in Earth Engine

I have an image collection(image) with 'system:time_start'. My function(iterate) is to get [img1, img1+img2, img1+img2+img3, img1+img2+img3+img4, img1+img2+img3+img4+img5]. But after I calculated, I ...
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2answers
37 views

What is the time interval for daily GPM IMERG product? 0:00 to 23:59 local time? UTC?

I'm processing a bunch of GPM IMERG Daily products and comparing to historical station data. These old met stations report daily precip from 9am to 9am of the following day. So I'm wandering what is ...
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1answer
133 views

Enabling Time on raster layers in ArcGIS Pro

I have several raster layers (all tiffs) in ArcGIS Pro and I would like to enable Time on each layer. This was straightforward in all versions of ArcMap 10 but not so here it would seem. As ...
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1answer
496 views

stars package in R. How to add time dimension in a stars object?

I have a raster stack (my_stack) and I converted it into a stars object: mystar <- st_as_stars(my_stack) That results in: stars object with 3 dimensions and 1 attribute attribute(s), summary of ...
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1answer
46 views

Adding time band as year to NDVI composite

I try to add time band to my NDVI time-series and using this function (took it from developers guide), for regression calculation. It looks like script is working but magnitude of slopes is extremely ...
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1answer
109 views

Find nearby points in space and time

I have a table that has an ID, point geometry and time. It's basically GPS coords and some other data. I want to be able to select all rows that interact (come close in space and time) to my target ID....
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63 views

Create isochrone along a given road

I want to solve this problem : given a departure point given an arrival point given an amount of time In which areas can I go while coming from departure to destination in the given amoint of time? ...
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2answers
116 views

Which time format does ESA use for Sentinel-3 file names?

regarding the ESA Sentinel-3 file name convention I have got a question; which time zone (GMT, CEST, ...) does ESA use? I could not find anything yet, even it should be a critical point for many users....
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1answer
73 views

How to add a time component in a heatmap?

I have a point file extracted from an AIS network. 1 year is about 900 million points. Each point has a timestamp. I want to make a heatmap for a longer period of time, but I want the heatmap to take ...
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2answers
125 views

Calculate time duration from military time with ArcMap Field Calculator [closed]

I have two text fields (STRTTIME, ENDTIME) which are are formatted as military time with leading zeros. For example, 0540, 1655. I want to calculate a new field with the time duration as integers (...
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43 views

Shift time in NetCDF files

I have a folder which contains (monthly) nc files from January 1980 to December 2015 with hourly data for different compounds (such as PM2.5, O3, NO2, NO, etc).The time is in UTC as follows: int ...
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84 views

Daily averages in local time from UTC

It has been almost 2 weeks since I started getting familiar with netCDF files and operators (NCO) and climate data operators (cdo) and I am not an experienced programmer. I have a folder which ...
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1answer
84 views

Mapping with time frame symbology in QGIS?

I am using QGIS 3.8, and I am making a map of archaeological sites. My table looks something like this: NAME - Coordinates X - Coordinates Y - Site_type - Data_type - Century_begin - Century_end ...
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1answer
189 views

PyQGIS output to specific layer

I have a Python script that I have exported from a QGIS model and I want to specify the layer it creates as output. If defaultValue=None it outputs 'Reportpmbc': '...
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0answers
114 views

Getting travel time while performing pgrouting i.e. what are parameters and function required?

While doing the pgrouting to find the shortest distance I got success in getting the output but when I thought to come up with the time consumed for travelling, I cannot find the proper source to get ...
2
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1answer
696 views

How long is a GPS epoch in microseconds?

My GPS is reporting dates from the previous epoch. How many microseconds should I add to the date to get the correct value? Since the 2019 GPS Week Number Rollover, my old GPS logger (QStarz BT-...
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1answer
452 views

What is Time of Validity in a GPS System?

What is time of validity in a GPS system? For defining time of validity, there are only a limited definitions available. My interpretation for time of validity is the built-in system time (like on ...
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0answers
34 views

How to include duplicate samples (same locations, different temporal sampling) in Geographically Weighted Logistic Regression? [closed]

I want to assess local most important predictors for a specific event within a region. The same locations (grid) were all sampled in two different time occasions. I am assuming predictors to be ...
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0answers
49 views

Time series condition through field calculator [closed]

I am attempting to filter some time stamped data which I have enabled through the Convert Time Field tool, depending on a true/false condition. I am doing this through the field calculator within ...
2
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1answer
425 views

Does GPGGA have leap second correction?

I'm trying to use GPS clocks to synchronize some measurements and I'm a little confused about the leap second correction between GPS time and UTC. I was wondering - does the GPGGA NMEA header have the ...
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1answer
109 views

Selecting points in polygon in a range of time (ArcGIS)

I have: - point GPS for people (time in seconds) - buffer GPS for a car (time in seconds) What I want to do is for each buffer GPS coordinate, I want to find the number of GPS people points inside ...

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