This form allows you to generate your own simulated VLBI data from specified array and target parameters and your own source image! Use this to debug your algorithm or to generate realistic data similar to your problem. Once you submit the form we will generate an OIFITS file with the simulated visiblities and bispectrum data along with a number of plots for visualization. Simulated data is generated using the MAPS software package.

Click here for a video tutorial of how to generate your own data!
Click here to autofill with sample parameters corresponding to observing SgrA* with the EHT 2015 telescope array.

Step 1: Select Image of the Emission

Select or upload an image that you would like to observe and specify the total flux density of the emission.

Total Flux Density (Janskys): Rotation (Degrees):


(under 512 x 512 pixels)
Add Image To Dataset
Sgr A* Model
When using these images cite
(Broderick et al., July 2011)
User Uploaded

Step 2: Select Direction and FOV

Identify the direction to the target source. Right ascension should be in the form HH:MM:SS.SS for hours, minutes, and seconds and declination should be in the form DD:MM:SS.SS for degrees, arcminutes, and arcseconds. Field of view is specified in arcseconds. Warning: You must choose coordinates such that your region will be observable from your observatory site (the first telescope you specify below) at the start time that you specify, otherwise the resulting output will be incorrect.

Field Of View Center: Right Ascension (HH:MM:SS.SS) Declination(DD:MM:SS.SS)

Field Of View Size:         Right Ascension (arcseconds)   Declination (arcseconds)

Step 3: Specify Telescope Array

Add the telescope locations and intrinsic parameters that you would like to use to simulate data

Initilization: Select a pre-loaded telescope
Name: Unique name for each telescope station (up to 12 characters)
East Longitude/Latitude: East longitude and latitude of the array center. For locations less than 180 degrees west of Greenwich a minus sign should precede the longitude entry.
X/Y/Z Position: Absolute X, Y, Z coordinates of each station (in meters) relative to the center of the Earth
Lower/Upper Elevation: Lower and upper elevation limits of the of the antenna in degrees
SEFD: System equivalent flux denisty of the antenna
Diameter: Antenna diameter in meters

Initilization Name East Longitude Latitude X-Position Y-Position Z-Position Lower Elevation Upper Elevation SEFD Diameter

Step 4: Specify Date and Time Data is Collected

Specify the time of when you would like measurments to be taken, and the time interval between measurements.

Start Time: Specify the time of your first observation in Universal Time (UT). The required format is "YYYY:ddd:hh:mm:ss" where YYYY is the year, ddd is the day number (e.g., December 31 is day 365); hh is the UT hour, mm is the UT minute, and ss is the UT second.
Scan Duration: The length of a continuous scan in seconds
Interval Length: The time in seconds between successive scans
Number of Samples: The number of successive scans of this type

Start Time (UT) Scan Duration (seconds) Interval Length (seconds) Number of Samples

Step 5: Specify Collection Parameters

Specify the center frequency and width of the observing channel in MHz.

Center Frequency (MHz):   Bandwidth (MHz):  

Specify your integration time in seconds (sometimes referred to as “dump time” or “record length”). This is not the total duration of your observation, but rather the sampling and recording interval of the data.

Integration Time (seconds):

Step 6: Add Noise and Generate Data

Simulate Without ANY Noise

Simulate Without Atmospheric Phase Errors

Simulate Without % Gain Error

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