Tagged Questions

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

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3
votes
0answers
31 views

Formula for maximum coverage of a geostationary satellite based on earth station elevation

I am trying to create a javascript function to represent the maximum coverage of a geo satellite for different antenna elevations (0 degrees, 5 and 10 degrees) with 3 leaflet polylines. The result is ...
4
votes
3answers
349 views

Free radar (SAR) satellite data

I'm looking for free (non-commercial use) sources of radar (SAR) satellite imagery. Does anyone know of sources?
1
vote
0answers
23 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 ...
2
votes
1answer
34 views

Computing the elevation angle of a GPS satellite with respect to the given receiver location

can anyone source an explicit formula for calculating the elevation angle for a GPS satellite as seen from a receiver. I can't seem to find one. Even a text reference would be great. I couldn't quite ...
0
votes
0answers
14 views

Aerial imagery not loading in GeoServer deployed under JBoss

I published a satellite image of a small town in GeoServer using image mosaic plugin. In Tomcat the layer preview is coming without any issue but when i try to do the same in Jboss the layer preview ...
1
vote
1answer
37 views

My RapidEye image won't appear in GRASS GIS

I have several RapidEye images that I want to use for object segmentation in GRASS GIS. When I import the the bands they all look like this and the same goes with a RGB composite: I've used these ...
0
votes
0answers
74 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 ...
1
vote
1answer
42 views

Easy Guide to ESA satellite data?

Can anybody provide user friendly guidance to ESA datasets? What is available? When will new stuff be available? I struggle to work out what might be interesting amongst the many websites and their ...
2
votes
1answer
84 views

Dark Object Subtraction QGIS

I'm trying to do Dark Object Subtraction (DOS) for a Spot2 and 4. I have calculated the TOA reflectance and now want to get the at surface reflectance. Using QGIS I would like to know how I can do ...
-1
votes
1answer
39 views

Most suited Remote Sensing [closed]

What will be the most suited remote sensing data to use for mapping highways in North America?
2
votes
1answer
39 views

Merging h5 files from VIIRS to gtiff

I am trying to mosaic all the data from VIIRS of a day into a single gtiff. I've already done it with MODIS data using GDAL. The problem it seems is that the coordinates of each h5 files doesn't seem ...
4
votes
3answers
68 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 ...
2
votes
1answer
44 views

What is the Scan Direction of a satelite image?

There are two possible values that I am aware of for describing the scan Direction of a satellite capture: Forward Reverse What is the meaning of Forward and Reverse scan direction? What are ...
5
votes
4answers
383 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 ...
1
vote
1answer
49 views

Can we manually select which satellites to use in solution? [closed]

For example, I have used below satellites ID in current solution: ID Signal Strength ______________________ 1 21 22 23 19 12 36 26 20 18 3 29 32 ...
0
votes
0answers
30 views

Where to get night satellite imagery of South Sulawesi, Indonesia

I need night satellite imagery of South Sulawesi, Indonesia but could not find any one my own. Does anyone know of sources? Free would be best but if quality and resolution is good i would also pay ...
0
votes
1answer
91 views

how to mosaic rasters in grass gis?

I am new user of GRASS GIS. I need to know how can i mosaic different satellite imageries using GRASS GUI? I was trying to use i.image.mosaic, but could not succeed. I have been looking for online ...
2
votes
0answers
117 views

Decision tree classification of satellite image in R

I want to classify satellite image in R using RWeka classifier, J48. I have a CSV file with the classes required, and raster data loaded in R. I am able to make the tree, however, I am not able to use ...
2
votes
1answer
72 views

Imagery on March 6, 2014 @ Lat 42dd55'22“ N, Long 079dd37'36” W

I am looking for any advice where to find imagery on March 6, 2014 (or a few days following) for: I have searched the USGS, ImageHunter, and Digital Globe with no luck. Does anyone have a resource ...
3
votes
1answer
100 views

Calculate ground nadir line from PV coordinates

I'm using an API which returns a satellite's PVCoordinates (Position/Velocity pairs). {P(1036869.5330731269, 6546536.584960848, 9.892293545390519E-11), V(-9994.355195123433, 1582.9503539842497, ...
0
votes
1answer
251 views

Projection to use with satellite image from Google Maps / Earth

I'm very new to anything concerning GIS so please forgive me if this question has been asked before, but I assure you, I've been trying to find an answer for quite some time now. Of course it is ...
2
votes
1answer
226 views

Is there any information in Sky Plot that is not in DOPs chart in terms of predicting accuracy in the field? (GPS data collection planning)

Joe only looks at DOPs chart and weather report for mission planning. Moe looks at both DOPs chart and Sky Plot and weather report. Is Joe missing out on something relative to Moe in terms of ...
1
vote
1answer
210 views

Convert measurement geometry from ground reference frame to satellite reference frame

I need to convert solar_zenith_angle, solar_azimuth_angle, platform_zenith_angle, and platform_azimuth_angle from a reference frame at the WGS84 surface to a reference frame at the satellite observer, ...
0
votes
1answer
41 views

Raster vertical pixel offset (ALOS AVNIR)

I am working with ALOS AVNIR-2 level 1a. There is a vertical offset/shift of each and every pixel column. It gives sort of a stripy appearance when zooming in. Does anyone have experience with this ...
2
votes
1answer
53 views

Need information about the Envisat satellite

I am new to remote sensing and I want to know about sensor design of Envisat satellite. Can anybody help me or preferably direct me to some good references?
2
votes
0answers
204 views

GLONASS Satellite Position Prediction using Almanac Data

GLONASS ICD has a section named "Algorithm of calculation of satellite motion parameters using almanac". It gives the formulas in order to calculate the position and velocity of the satellite. ...
2
votes
0answers
114 views

AGI STK Server alternative

AGI has a server product called STK Server that exposes REST services to perform satellite acquisition planning. However the cost is astronomical $200k+ (pun inteded). They also have STK components ...
2
votes
1answer
61 views

From where I can get 4-band satellite imagery of Sweden?

I'm looking for good quality, fine resolution 4-band satellite photos of Sweden for academic use (and I'm willing to pay for it). What I'm after is as detailed as possible photos of certain part of ...
1
vote
1answer
220 views

Convert from Mercator to transverse Mercator projection in C++?

I'm writing code to import images from a WMS server into some software. However, the software expects the images to be in transverse Mercator, but the WMS server provides it in Mercator. This ends up ...
2
votes
1answer
727 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 ...
10
votes
1answer
213 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 ...
2
votes
1answer
153 views

Lack of Options in Gdal Tool “Build Overviews” QGis

I am using QGis 1.8 and I want to build overviews (pyramids) for satellite imagery using the Gdal Tool. I would like to use the resampling method "cubic convolution", but the option doesn't exist ...
3
votes
0answers
90 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 ...
0
votes
2answers
371 views

georeference IMG file in qgis

I have a problem: I'm trying to georeference a satellite image (ASTER, Erdas Imagine file *.img) in QGis. I have georeferenced with QGis before and never had any problems. The file is georeferenced ...
1
vote
1answer
186 views

getting a merged color satellite image from red,green, blue, pan, and nir tifs

I am using Tiff images from Digital Globe and trying to get a color satellite image. I have merged the red, green, blue, pan and nir tiff files into one file. I then changed the band properties to a ...
1
vote
1answer
534 views

How do you scan/quantify vegetation using satellite images?

I am relatively new to GIS (about 4-5 months in) I did not receive any formal education about this so I am completely clueless about how to go about measuring/quantifying vegetation using satellite ...
3
votes
0answers
89 views

Using Quickbird to discriminate vegetation response and spectral signatures - which season?

I have a study area in N. Florida loblolly pine plantation with 3 treatments (drought, fertilization, drought+fertilization, control) and 4 replicate plots. All plots will be in the same scene. These ...
11
votes
1answer
292 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, ...
2
votes
0answers
376 views

Principal Component Analysis in QGIS

How do I go about to perform a band ratio and Principal Component analysis in QGIS? I need to derive principal components from ratios of landsat TM bands .
3
votes
2answers
350 views

Tasseled Cap Transformation Rapid Eye

I want to do tasseled cap transformation on rapid eye data. the main question would be about the parameters which are used. Somebody has a suggestion?
3
votes
0answers
40 views

Projection string for GOES-WEST

Full-res, full-disk GOES-WEST images are available from goes.gsfc.nasa.gov. Is it possible to rig up a projection string for these images? We know the center pixel is at (0N, 135W) and the satellite ...
2
votes
1answer
130 views

Determining the transformation between a satellite image and long/lat

I'm trying to overlay some data onto a satellite image of the UK. The image is a hi-resolution version of the image below (originally from dundee university): ...
2
votes
1answer
299 views

VIIRS Day Night Band and alternatives for night satellite images

Has anyone worked with VIIRS Day Night Band? I want to download few images to get a map of night scene of Central Europe (city lights etc). I use friendly interface at NOAA ...
1
vote
0answers
222 views

Raster satellite images for QGIS

When I try to apply a downloaded GIS satellite (t=rimage to Quantum, it doesn't seem to open properly. There must be a step-by step description on how this would be done effectively. Can anyone tell ...
5
votes
1answer
643 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
763 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 ...
0
votes
1answer
1k views

Does GPS Navigator send data to Satellite?

Does GPS Navigator send data to satellite? Is this true about regular devises available in the market?
1
vote
1answer
1k views

Openlayers zoom limit with Google Maps

When using Openlayers I am unable to achieve the same zoom level that Google Maps allows. For example, if I embed a Google Map in my web-page I can zoom in to the building level in a city. When using ...
7
votes
4answers
906 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 ...
2
votes
3answers
290 views

Finding Satellite Imagery For Use Without Internet Connection

So, I am not a GIS expert. I just write software and I've done some work with ArcMap, ArcGIS Server, and FalconView. What I need is world wide satellite imagery I can use on a local machine. Street ...