McIDAS-X Learning Guide
Version 2020

[Search Manual] [Table of Contents] [Go to Previous] [Go to Next]

Satellite Imagery - Displaying Satellite Data

Before displaying satellite data, you must know the ADDE dataset name under which it is stored. The DSINFO and IMGLIST commands can list information about image datasets you have access to. Once located, you can display the images using the IMGDISP command.

When you display an image on a frame, McIDAS creates a frame directory for the image which lists the frame number, sensor source, date, image time, band number, image coordinates, magnification factors, and ADDE dataset name and file position number. The FRMLIST command lists the frame directory.

You can display images one at a time or in a sequence. If the areas on disk are chronologically ordered, an entire set of images can be sequentially loaded using one IMGDISP command with a repeat factor.

In this exercise, you will select two images and display them on frames, list the frame directory for one frame, and display a sequence of images using the IMGDISP command with a repeat factor.

  1. Start a McIDAS session.
    At the Unix prompt:
    Type:  mcidas
    Your session should still be set for twenty frames from the last time you changed the Configuration GUI. If not, set it for twenty frames, as described in Getting Started.
  2. Setup a new dataset of 10 Mesoscale ABI images of Hurricane Dorian. Download a set of Level 1B netCDF files from a FTP site. For this example, it is assumed the data has been placed in the directory <local-path>/Data/Satellite/ABI_data/Meso1.
    Download the files from ftp.ssec.wisc.edu.
    ftp ftp.ssec.wisc.edu
    login anonymous
    prompt
    binary
    cd pub/mug/Data/Satellite/ABI_data/Meso1
    mget OR_ABI*
    Example file name:
    OR_ABI-L1b-RadM1-M6C02_G16_s20192461800251_e20192461800309_c20192461800346.nc
  3. Run the DSSERVE command to access the Level 1b netCDF imagery files.
    Type:  DSSERVE ADD DORIAN/M1 ABIN TYPE=IMAGE DIRFILE=’<local-path>/Data/Satellite/ABI_data/Meso1/OR_ABI*’
  4. List the area directories for the first 3 images in the DORIAN/M1 dataset.
    Type:  IMGLIST DORIAN/M1.1 3
    
 Image file directory listing for:DORIAN/M1                        
  Pos Satellite/         Date       Time      Center   Band(s)     
      sensor                                 Lat  Lon              
  --- -------------  ------------  --------  ---- ---- ------------
    1  GOES-16        3 SEP 19246  18:00:25    28   79 2           
    2  GOES-16        3 SEP 19246  18:01:22    28   79 2           
    3  GOES-16        3 SEP 19246  18:02:22    28   79 2
  5. List the directories of all images of the DORIAN/M1 dataset that contain images between 18:01:00 and 18:05:00 UTC on day 2019246.
    Type:  IMGLIST DORIAN/M1.ALL DAY=19246 TIME=18:01:00 18:05:00
    
IMGLIST DORIAN/M1.ALL DAY=19246 TIME=18:01:00 18:05:00            
Image file directory listing for:DORIAN/M1                        
 Pos Satellite/         Date       Time      Center   Band(s)     
     sensor                                 Lat  Lon              
 --- -------------  ------------  --------  ---- ---- ------------
   2  GOES-16        3 SEP 19246  18:01:22    28   79 2           
   3  GOES-16        3 SEP 19246  18:02:22    28   79 2           
   4  GOES-16        3 SEP 19246  18:03:22    28   79 2           
   5  GOES-16        3 SEP 19246  18:04:22    28   79 2
  6. Display the first GOES-16 visible 0.5km image on frame 1.
    Type:  IMGDISP DORIAN/M1.1 1
    Notice that the bottom of the image has an annotation line which lists the frame number, satellite type, sensor source, Gregorian date, Julian date, UTC time, upper-left corner image line and element, and resolution. Note the Note the resolution of 1.0, this is the base resolution (best) of the satellite, so it lists 1.0, not 0.5 in the frame label. Run the following command to confirm this:
    Type:  IMGLIST DORIAN/M1.1 1 FORM=ALL
  7. List the frame directory for the current image on frame 1.
    Type:  FRMLIST
    Information about the frame number, sensor source, band, date, time, and ADDE dataset/position number is displayed for the image. 
    
  FRMLIST                                                                                
    Frame   Satellite                                                                    
   [panel]  Sensor       Band     Date       Time   Data Source                          
  --------- ------------ ---- ------------ -------- -----------------------------        
       1[1] GOES-16         2 03 Sep 19246 18:00:25 DORIAN/M1.1                          
  FRMLIST: Done
  8. Display three areas that are in sequence using one IMGDISP command.
    Type:  IMGDISP DORIAN/M1.1 2 REPEAT=3;SF 2
    The repeat factor is 3; therefore this entry displays three images in sequence, on frames 2, 3, and 4.

  9. Step through the frames to view the images.
    Press:  Alt A
    Press:  Alt B
  10. Erase the contents of frames 2 through 4 to prepare for the next exercise.
    Type:  ERASE I 2 4

[Search Manual] [Table of Contents] [Go to Previous] [Go to Next]