Questions tagged [satellite]

In the context of spaceflight, it is an object which has been placed into orbit by humans.

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34
votes
4answers
40k views

Why is GPS a free service?

The Global Positioning System (GPS) is a free service that is owned and operated by the U.S. Government and is always available. When we buy a GPS device, we don't pay a monthly fee or pay a tax for ...
33
votes
8answers
24k views

Creating shapefile showing footprints of Rasters?

I have around 1,000 satellite images in tiff format, and I want to create a shapefile which will serve as an index to the rasters. This is something similar to a raster catalog, but I do not want to ...
30
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5answers
7k views

OpenSource Remote Sensing Tools for Classifying Roofs

with envi image processing and classification tools, you can get roofs from images with some spectral value and then you can convert it some vector data for your app. in python with OpenCV which have ...
28
votes
4answers
980 views

Is there an online catalog for declassified Soviet Union Spy Satellite images (Zenit-4, Resurs-F1, Okean)?

I'm a glaciologist user of declassified US Spy satellite images (Corona Key Hole satelites, Hexagon, etc.), that provide an extraordinary record of glacier extent at resolutions equivalent to about 4 ...
17
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7answers
5k views

Seeking Satellite Imagery Providers? [closed]

I'm building a web application - my requirements are: Must have global satellite imagery. Must have easy to use API's that are capable of geoJSON data imports, mouse and keyboard gestures, etc. To ...
17
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1answer
1k views

How to detect roads from satellite images?

OpenStreetMap has announced a Bing API to detect roads. I want to know what is the theory behind road detection and if there is any open source tool that do that.
15
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3answers
8k views

Which remote sensing satellite is best used for vegetation extent mapping

I'm currently writing an assignment for my remote sensing class and while I think I have correct answer was wondering what people who do this stuff for a living think. The question is: which ...
12
votes
2answers
42k views

Identifying image location?

I have a satellite image of only one part of some city with a lot of vegetation. I need to find out where is that image taken. Is there any way to find out where it is taken on Google Maps, Google ...
12
votes
2answers
857 views

How precise are overpass times of sun-synchronous satellites?

sun-synchronous satellites, as their name say, acquire scenes at the same solar time of the day when they pass over the same location. According to this site, sun-synchronicity is achieved by taking ...
12
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1answer
2k views

Automating roof orientation detection from satellite imagery?

A while ago I did a neighbourhood roof orientation survey for solar panel deployment, by visually checking each roof and marking individually whether they were south or almost south-facing. As this ...
11
votes
1answer
752 views

Assign projection to a satellite image

Today I stumbled upon a picture taken from the ISS looking down Europe and it is really beautiful. So, I started thinking I could add more to the picture. Like world borders, cities, road network, ...
10
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4answers
2k views

How can I work with 3+ Gigabyte TIFF Files?

While I don't work in GIS myself I'm trying to support one of our users here who looks after all our mapping and GIS data. We've received a 3.2GB Tiff image containing satellite imagery of our site ...
10
votes
1answer
381 views

How did Nova create the globes in Earth From Space?

Nova recently aired Earth From Space on PBS. (I highly recommend it.) Also found here on youtube. Produced in extensive consultation with NASA scientists, NOVA takes data from earth-observing ...
10
votes
1answer
663 views

50cm imagery - aerial or satellite?

The area of interest is 1450 km2. My options are: 50cm newly collected aerial natural color imagery for $28,300 OR 50cm recent archival satellite imagery (includes near IR band) for $20,600 The ...
9
votes
5answers
25k views

Free radar (SAR) satellite data [closed]

I'm looking for free (non-commercial use) sources of radar (SAR) satellite imagery. Does anyone know of sources?
9
votes
5answers
360 views

Tools for (semi) automated woodland tracing from satelite images

I'm trying to draw woodlands in OpenStreetMap, using Yahoo sattelite images. JOSM editor has some plugins that try to automate the process - you have to click inside the area and the plugin finds the ...
8
votes
5answers
3k views

Where can I download free satellite imagery of Cambodia for offline use?

I am an entry level GIS user - I have had one semester of GIS in college. I have successfully downloaded raster satellite imagery from Seamless (tiff files) for my class project. Now I am trying to ...
8
votes
1answer
262 views

Free satellite data availability for moon [closed]

What are the satellite raster and vector data sets available for mapping the moon that can be freely downloaded? I need to know the availability and type of the data sets from which mineral mapping, ...
7
votes
1answer
8k views

Is it possible to get satellite image tile sets from something like openmaptiles tiles offers?

I am able to get an offline tile set for the USA from here. However, I was wondering if it is possible to get satellite imagery of those tile sets. I have been checking online and most require to be ...
7
votes
1answer
660 views

Free open satellite or other remote sensing data for night time?

I usually work with daytime satellite images to do some image classification (mostly Landsat data from the USGS EarthExplorer). Right now I'd like to check at some night time images to work on city ...
6
votes
2answers
2k views

Identify the latitudinal and longitudinal point directly beneath an object in space

Given the azimuth and altitude / latitude and longitude from the observer to the satellite, how can I accurately find the latitude and longitude of the point of intersection directly under the ...
6
votes
1answer
242 views

How to know which satellite took the image?

I am having trouble finding which satellite took the images I have. Most are from digital globe. I read through the metadata and the .imd file. I found date and time but not the name of the ...
6
votes
3answers
939 views

Colour matching satellite imagery from different time periods

Is it possible to colour match two separate satellite images taken at two different times? I am working with two high resolution, multispectral images that were taken approximately one year apart and ...
6
votes
2answers
5k views

GPS Module Without Velocity or Altitude Limitations

I am looking for a GPS module that I can use in a high-altitude project. The problem I have discovered is that GPS manufacturers are required to place a set of restrictions on GPS modules. The ...
5
votes
2answers
822 views

Why does the resolution decrease with increasing incidence angle in the Sentinel-1 SAR sattelite

On this link (Sentinel1 webpage for a SLC product), the resolution is written as a range from the highest corresponding to low incidence angle, to the lowest resolution corresponding to high incidence ...
5
votes
4answers
826 views

What satellite imagery would help to show spring locations?

I've got lots of tiny streams on a hydrography shapefile. Historic texts indicate that certain ones have headwaters at "sources" or springs, and I want to try to find these. Browsing the historical ...
5
votes
2answers
937 views

Calculating new satellite position given pseudorange measurements

I'm looking for a reference/text for an explicit formula to calculate a satellite position given pseudorange measurements from later epoch times. I've seen a lot of matlab code on the internet but I ...
5
votes
2answers
6k views

Free Web-service providing Satellite Images

Is there any web-service currently available which is hosting satellite images as open-source, just like OSM web-service hosting vector maps? We want to make a real-time traffic monitoring commercial ...
5
votes
1answer
2k views

Google maps satellite view Pricing and limitations

This script at openstreetmap shows how one can use google's Satellite view as a layer on top of others. I noticed that to do so, one does not need to supply any API key. Does that mean that there are ...
5
votes
2answers
323 views

Pattern search in satellite imagery

I would like to search for the specific buildings (polyhouse in my case) on the map like the one shown here Are there any free options available which can give me lat and lng of such shapes/features ...
5
votes
1answer
339 views

Using remote sensing satellite for chlorophyll mapping?

Location of my research are reservoirs which have an area of 47 and 62 km2. I need a better image resolution than Landsat(Pan).
5
votes
2answers
5k views

Is there an industry-standard official mapping of GLONASS satellites to “PRN” values?

In the U.S. GPS system, satellites are uniquely identified by the PRN number broadcast by each satellite. This ID is usually visible on most GPS receiver platforms that provide access to individual ...
5
votes
3answers
215 views

Can a satellite go over the same area in different passes overtime

Can a sun-synchronous satellite (let's consider Sentinel-1) go over the same place, one time in an ascending pass and the next time (or few times after) in a descending pass?
4
votes
2answers
929 views

Satellites to retrieve UV bands

I want to retrieve some satellite images with UV bands, but I don't know which satellites are providing UV bands and whether we can freely download them. I have already downloaded Modis and Landsat ...
4
votes
1answer
488 views

Can someone explain in simple terms the licence on Google “satellite” images? [closed]

What can I and can I not do with the Google satellite images?
4
votes
2answers
252 views

Sentinel-2A: Begin of operational period?

This also might be of interest here, as it is an important data source: When does Sentinel-2A finally become operational and deliver images regularly? I tried to find information on that, but ...
4
votes
3answers
3k views

Is there an industry-standard official mapping of Galileo satellites to global "PRN”/ID values?

In the U.S. GPS system, satellites are identified by the PRN number broadcast by each satellite. This ID is usually visible on most GPS receiver platforms that provide access to individual GPS ...
4
votes
1answer
898 views

I am looking for an alternative solution to openlayers for satellite imagery in QGIS? [closed]

Does anyone have any other suggestions for sources of satellite imagery on QGIS? Openlayers is becoming extremely temperamental in QGIS 2.6 (Google imagery not bothering to work anymore, Can't zoom in ...
4
votes
1answer
573 views

Maximum Solar Zenith Angle for Landsat-8 images

Heliosynchronous satellites enter a darkness region at high latitude in winter. They are most of the time programmed not the capture an image when the solar zenith angle becomes too large because the ...
4
votes
1answer
281 views

Is there a tutorial explaining the basics of WMS?

I'm building some software that needs to download satellite map images to display behind some survey charts. I understand that, to download these images, I need access to a Web Map Service. The only ...
4
votes
1answer
28 views

What do horizontal (H) and vertical (V) polarization mean for satellite radar?

I'm reading about synthetic aperture radar (SAR), and one of the basic concepts is that the transmitted and received signals can have "horizontal" (H) or "vertical" (V) polarization, but I can't find ...
4
votes
1answer
943 views

Python folium package for 'satellite' map

I am trying to have a zoomable satellite map for my Transportation network analysis. Other free maps all OK but could not get satellite to work. I am using: token = 'pk....
4
votes
1answer
599 views

What is the DNSC08 Mean sea surface model ellipsoid based on?

Does anyone know what Danish Space centre DNSC08 mean sea surface model uses as the reference ellipsoid? there is no meta data on the web site: http://www.space.dtu.dk/English/Research/...
4
votes
0answers
54 views

Seeking Public API to get GPS satellite's position?

Is there any public availible API that allows you to retrieve the current coordinates of satellites such as GPS and Galileo? I've only found ways to get Satellites Ephemeries and calculate the ...
4
votes
1answer
116 views

FCC Galileo Waiver: What does it mean in practice? [closed]

Today the FCC approved the use of Galileo navigation satellites in the United States. According to gps.gov, The Federal Communications Commission (FCC) rules require licensing of non-federal ...
4
votes
0answers
269 views

Using QGIS for current SAR (Search And Rescue) operation?

A friend of mine, Christiaan Wilson is missing since 15 may during descending the Dhaulagiri mountain in the Himalayas. One searching team has already finished one operation. A second is on the way. ...
4
votes
2answers
150 views

Automatic split a mosaic of satellite images into pieces

I have a mosaic of satellite images, but for the analysis, I need to define the boundaries of each part. Does anyone know how to do it in an automatic way? I need to get the red boundaries like on the ...
3
votes
2answers
2k views

Where can I find non-rectified stereo satellite imagery?

I'm looking for free (as in beer and as in commercial-use-friendly freedom) sources of stereo satellite imagery. I assume that such imagery should not be rectified since that would remove the benefits ...
3
votes
3answers
512 views

High resolution satellite

Can any one tell me from where I can buy commercial High resolution Satellite images for Biodiversity research ? I need some websites that sells these kind of images ?
3
votes
1answer
5k views

How do I clip/mask a satellite photo to a polygon?

Given a shapefile composed of contiguous polygons, I'd like to clip (or mask) regions of satellite photo to the polygon outlines, and export each resulting raster in medium resolution for further ...