The distance-independent relationship between two points in space that specifies the angular position of either with respect to the other

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16
votes
2answers
4k views

How can I calculate the bearing between two points in PostGIS?

How can I find the bearing between two points in PostGIS? Please specify in your answer whether or not the method producing a bearing on the spheroid, or a planar bearing.
11
votes
2answers
280 views

Which weather on my road? Looking for a spatial weather forecast web service

My friend Bob goes from A to B leaving tomorrow morning at 6:00. There are many direction services that indicates him short, fast and/or cheap routes. Bob does not like to drive under the rain and ...
8
votes
1answer
681 views

What determines “west” in Antarctica?

Hopefully this isn't so far afield as to get banned - apologies in advance to those who think it doesn't belong. This article discusses a region of Antarctica which is described as "West Antarctica". ...
6
votes
1answer
837 views

How do I find least cost path over a DEM based on slope magnitude and direction?

What sort of algorithms can I use to find a least cost path through a DEM where it costs more to traverse a cell going downhill or uphill than it does to follow the contour of the land? All the ...
4
votes
1answer
435 views

Understanding percentage drop-raster (flow direction-tool)

I'm creating a Topographic Wetness Index using a python script (http://arcscripts.esri.com/details.asp?dbid=16750) As I don't want this just to be a blackbox, I'm trying to understand the different ...
4
votes
0answers
156 views

Advanced GMaps directions

I try to create an application for taxis. The application will be GMap based. On the map will be marked the region in which the taxi driver is working in. The region will be a polygon designed by ...
3
votes
2answers
4k views

How to show polyline direction in ArcGIS for Desktop (ArcMap)?

can someone tell me how I can show the direction of a polyline as it was digitised? I need this to check if my network analysis is obeying one way streets...I know of a tool in Xtools that can do this ...
3
votes
1answer
489 views

ArcMap - Display direction of points

I imported a few geotagged images and created a points shape showing their locations (or more accurately, the location of the camera) with the "Geotagged Photos to Points" tools. The attribute table ...
3
votes
1answer
517 views

How to get the Flow or directional raster map using GRASS?

Aside from using r.fill.dir in GRASS, is this the script to produce the Flow or directional raster map? Is this the output for the script ...
3
votes
1answer
35 views

Problem with flow lines in ArcMap

As a part of my PhD I have to map the rivers of Northern Peloponnese, Greece. I have downloaded two DEMs from Nasa Reverb, which I connected with "mosaic to new raster". I have started the usual ...
3
votes
1answer
73 views

How to display bidirectional flows?

I'm working on a map showing oil shipping. Basically, I have a a series of nodes/line segments that make up the shipping network. I've joined the sums of oil that traveled along each node, so can ...
3
votes
2answers
91 views

How to deal with Roundabouts in PgRouting

Can anybody guide me to to deal with roundabouts in pgrouting?? I have some roundabouts in my road network and when i try to make route from one point to another, it gives me wrong direction where it ...
3
votes
2answers
1k views

How to display arrows on pipes from upstream to downstream using QGIS?

I am trying to display arrows on pipes of a sewer network so their direction is from upstream to downstream edges of the pipes. I have managed to display those arrows on a polyline layer (which is ...
3
votes
1answer
719 views

Driving directions and multi-modal route planning service for a city with OpenStreetMap data

First off I'd like to mention that I've never come close to anything-GIS until a few weeks ago when I thought of this. So please expect some layman's questions. I'm looking to create driving ...
3
votes
1answer
371 views

Is there an open source directions webclient for pgRouting like the directions API from Google?

I am looking for an open source webclient with (Google) directions functionality (like draggable lines to create extra waypoints) based on an pgrouting database (with an osm2pgrouting topology). I ...
3
votes
2answers
149 views

Identifying the side of a point from the closest polyline in ArcMap 10.0

I have a set of polylines (a network of streams and rivers) with information on the left and right side of the streams on riparian structure. I also have locations (points) of either side of the ...
2
votes
2answers
551 views

how feasible is building my own map server? providing GeoCoding, Directions and Navigation

My need is a heavy use of routing. same as Google's Directions API. I'm looking for a viable alternative to abusing google and paying them too much. how difficult is it to have my own server for that ...
2
votes
2answers
128 views

ArcGIS lines to polygons without holes

I have a dataset with contours. Depression contours are separate of the normal contours and need to be digitized counter-clockwise. Still, there are usually some faulty ones with wrong direction and ...
2
votes
1answer
124 views

directional line symbol ArcGIS vs ArcView 3

Is this possible in ArcGIS to have variable number of arrows on the line to show direction? This is an ArcGIS example, where I can have fixed (1,2,3,4,5...) number of arrows and it stays the same ...
2
votes
1answer
51 views

Draw line with lon, lat, distance and azimuth

I have table in PostGIS with lon, lat, distance and azimuth columns. I want to make Geoserver draw a line through first point with given length and direction. I can turn lon and lat to geometry in ...
2
votes
1answer
56 views

Direction of movement with points2paths in QGIS

I have a data set containing ship movements. I used the Points2paths plugin in QGIS to connect the points with the ship's names as factor and the time the signal was picked up as sorting value. Now I ...
2
votes
2answers
206 views

Working out parcel direction

I am looking at applying a direction indicator to land parcels and houses (in MasterMap). effectively, I am looking at applying a direction indicator to the land and the buildings associated to the ...
2
votes
1answer
70 views

Euclidean direction

i'm trying to calculate the euclidean direction, in ArcGIS its very easy using the Euclidean Direction tool of Spatial Analyst but in QGIS i don't find how to do it. Any tips for this in free ...
2
votes
1answer
33 views

How to detect other objects are on which side of an object based on lat long

I am working on a system that detects the lat/long of vehicles. I want to track other vehicle's position: left, top-left, right, top-right, bottom-right, bottom-left etc based on lat/long. I have ...
2
votes
0answers
75 views

Finding number of left and right turns for each shortest route

I have a network dataset for a city. I have, lets say, 200 trips that are made in that city. I constructed the shortest route for the every pair of the trips, and also the actual route travelled by ...
2
votes
1answer
249 views

Knowing acceleration, gyro and compass data how to calculate north direction [closed]

I have a small video camera with an attached sensor. I can get from the sensor his acceleration, gyro and compass data. Knowing this data I need to rotate the camera so that it will look strictly ...
1
vote
1answer
74 views

How can I create individual directional point symbols in MapInfo?

I have a point tab file where one of the attributes is a 0-360 direction. I want to create an arrow symbol for each point with the arrow pointing in the direction listed for that point in the table. ...
1
vote
1answer
36 views

Using Copy Traversed Features to count turns for a route result in Network Analyst

I have the output of the route layer. And I want to determine the number of right and left turns for each route. For that, I used the COPY TRAVERSED ROUTE FEATURES tool from Network Analyst. However, ...
1
vote
2answers
147 views

How to convert Direction Of Travel OSM vectors from a “system” to another?

I have a painful doubt according Direction of Travel (DOT) vectors in OSM data. I'm using ArcGIS10, and a OSM data shapefile. I have a OSM road layer, that has many "Both ways" vectors and many "One ...
1
vote
1answer
108 views

Route planning needs double click

I am new to Stack Exchange so i hope i can prepare my question in an adequate way. I try to make a small route planning application. A start address should be entered and the destinations are fixed. ...
1
vote
1answer
28 views

Keep direction information after intersect operation with fishnet

I will try my best to describe my question here: All the operations are done with ArcMap 10.1. I have a shapefile, which represent the stream segment network of a watershed produced from ArcHydro ...
1
vote
1answer
87 views

Flip multiple vectors

I have thousands of vectors (out of several million) which I need to flip, for directionally purposes (Network Analyst). The vectors in question are annotated that their directionality has been ...
1
vote
1answer
153 views

Calculating field length in certain directions (raster)

Currently I'm working on winderosion. For my purpose I like to calculate the length of agricultural fields in certain wind direction. I would like to do it for raster. To be more precise: I have ...
1
vote
1answer
388 views

Small Idea to get best path between two points

Guys I don't know if its a good place to post ideas or to ask general questions. Still as the question is related with maps service, I am posting it here. If it's not the right place, please move me ...
1
vote
1answer
2k views

google maps V3 : in javascript api, render route obtained with web api

I have to obtain route directions with the Google maps v3 WEB (http request) api (computations are made server-side, based on this data, without client interaction, so no JS available). Then, the ...
1
vote
0answers
21 views

How to stop drawing the polyline in Google maps when path reaches in some defined area near the destination?

I am trying to draw the polyline between the 2 points and my requirement is, the polyline should stop drawing when it reaches the specified area surrounding the destination. I mean I don't want the ...
1
vote
0answers
33 views

Make a line from a set of GPS points close to a specific GPS point with PostGIS

I have to develop a map-matching algorithm. At the moment I only match GPS points with the closest road segment. I'm looking for a way to compare the directions between a GPS point and a road to ...
1
vote
0answers
69 views

How to determine ring orientation from lat/long coordinate points?

We have some set of point coordinates in lat/long which contribute to a polygon. From this set how do we determine the polygon is clockwise or anticlockwise?
1
vote
2answers
88 views

How to show street direction on map?

I am using sharpmap to render my OPEN STREET MAPS (osm) maps. i need to show the direction of one way streets on my map. How can i do that?! After googling i found SharpMap.Rendering.Symbolizer and ...
1
vote
1answer
57 views

How can I calculate the nearest distance to a landscape element taking the direction into account (i.e. slope direction, prevailing winds)?

I am trying to build a layer of distance to relevant landscape elements in a watershed. To be relevant, a landscape element must be downstream with respect to the runoff direction.  Clearly, I want ...
1
vote
0answers
110 views

How to deal with direction in pgr_ksp (K shortest path)?

I am working on a android app for navigation with PostGIS and pgrouting. I have implemented pgr_dijkstra and its working fine. I am not considering direction in routing at this point and just want ...
1
vote
0answers
585 views

Arrow flow lines from a contour map

using QGIS (or even GRASS) is it possible to label a contour lines shape with arrows that indicate the flow direction? Briefly: I have a point shape with elevation values. I make an interpolation map ...
1
vote
0answers
107 views

How to indicate a change in transport mode for directions in a multimodal dataset

When I solve a route and generate directions for my multimodal dataset, the end product is not very user friendly: The pedestrian started walking along Main Street and then boarded a bus to travel ...
1
vote
0answers
346 views

Avoid backtracking while creating loop in Google Map API 3

I am trying to build a solution where i would create loop by google map. My first and only business rule is there should not be any repeated route. But with my demo ...
0
votes
1answer
185 views

Does OSM data contain the direction of travel?

I was looking for Direction of Travel (DOT) information inside OpenStreetMap shapefiles, but only I've just found "ONEWAY = 1 or 0", but nothing about its direction. If I work on an OSM editor, I can ...
0
votes
1answer
118 views

Determining direction of longest segment of polygon?

I have a shapefile with 9000 agriculture fields and what I like to do is to determine for each field (=each polygon) the direction of the longest segment. For instance, the selected polygon in the ...
0
votes
2answers
419 views

Using grayed out distance/direction tool in ArcGIS for Desktop?

I have a set of five points (all with specific latitudes and longitudes) and I want to create a set of points which will be about 80 kms from the first set. I understand that I can use the ...
0
votes
1answer
120 views

Distance-direction computation of lines with exactly/more than two nodes?

A distance and direction tutorial provided as an Answer at How to add Direction and Distance to attribute table? uses: xat (0 ), xat (-1 ) and yat (0 ), yat (-1) for start and end points of lines; ...
0
votes
1answer
84 views

How to compute and fill One-way field in a street shapefile according spacial position

I think it is something complicate, but I hope someone could bring up any idea about. I'm using ArcGIS10, and I have a "One-way roads" shapefile with a One-way field with Y/N. But I need to create a ...
0
votes
2answers
265 views

Updating a column with line direction in MapInfo

I was wondering if there is a way to update a column in MapInfo with the digitised line direction. I have two TAB files, one is complete lines and the other is sections of the same lines (both have a ...