Viking Camera Stamp Layer

From JMARS Wiki

The Viking Camera Stamp Layer will display stamps for all the observations made by the visible cameras on the Viking 1 & 2 orbiters. The search interface is similar to the THEMIS Stamp Layer, but there are changes that allow users to search for images by the many parameters associated with Viking camera images.

[edit] Open the Viking Camera Stamp Layer

Open the Stamp Layer: Chose "Add New Layer" -> "Stamps" -> "Viking Stamps".

Search Parameter Categories: The search parameters are divided into categories since there are so many of them. Clicking on the down arrow on the right side of the category name will reveal all the search parameters in that category. The categories are:

• Basic Parameters
• Advanced Parameters

NOTE: A search can be done with parameters from multiple categories.

Enter Search Parameters: It is not necessary to enter values for each parameter, but the more specific your search the faster it will be. The allowable values for each field are given in the quick reference table below followed by more detailed descriptions of each search parameter.

Perform Image Search: Clicking OK will make the Stamp Layer perform the search and display the results. Depending on how specific the search parameters are, it may take the Stamp Layer a few minutes to find and create stamps for all of the images. Once the stamps are displayed in the Viewing Window, users can right-click on an outline to either render the image (display the image data in JMARS) or view the image in a web browser.

Viking Search Parameter Glossary

Filter Type

Acceptable Values

Basic Parameters
Image ID(s)	Any Specific Image ID Numbers
Spacecraft Name	Viking 1 - Only images from the Viking 1 orbiter Viking 2 - Only images from the Viking 2 orbiter Both Orbiters - Images from the Viking 1 and Viking 2 orbiters
Min/Max Longitude	0 - 360 - East Longitude = Positive, West Longitude = Negative Blank - All Longitudes
Min/Max Latitude	90 - -90 - North Latitude = Positive, South Latitude = Negative Blank - All Latitudes
Min/Max Orbit	1-1485 - Viking 1 1-706 - Viking 2 Blank - All Orbits

Advanced Parameters
Mission Phase	Continuation Mission Extended Mission Pre-Orbital Science Primary Mission Survey Mission
Instrument	VIS Camera A - Only images from Camera A VIS Camera B - Only images from Camera B Blank - Images from Camera A and Camera B
Filters	ALL Blue Minus_Blue Violet Clear Green Red
Sample Resolution (km)	0.0070-30.0000 Blank - All Sample Resolutions
Line Resolution (km)	0.0070-32.5000 Blank - All Line Resolutions
Local Solar Time	00:00-24:00 - Given as HH:MM Blank - All Times
Min/Max Solar Longitude	0 - 360 - 0=Northern Vernal Equinox Blank - All Solar Longitudes
Min/Max Phase Angle	0 - 180 - 0=MOC and Sun In-Line, 90=MOC and Sun at 90deg Angle Blank - All Phase Angles
Min/Max Solar Incidence Angle	0 - 180 - 0=Sun Directly Overhead, 90=Sun on the Horizon Blank - All Incidence Angles
Min/Max Emission Angle	0 - 180 - 0=Viking Directly Overhead, 90=Viking on the Horizon Blank - All Emission Angles
Min/Max North Azimuth Angle	0 - 360 - 0=Image Perpendicular to Longitude Lines, 90=Image Parallel to Longitude Lines Blank - All North Azimuth Angles
Min/Max Slant Distance	0 - 760,000 - Distance from sub-orbiter point to image center (in meters) Blank - All Slant Distances
Notes	Any Text Blank - All Notes

Search Field Descriptions

Image ID

A unique identifier for each image commanded; follows the pattern XXXMYY, where:

a) XXX is the zero-padded orbit number

b) M is the spacecraft id (Viking Orbiter 1 = A, Viking Orbiter 2 = B)

c) YY is the zero padded, two-digit image number from the specified orbit

Spacecraft Name

This field identifies which of the two identical Viking orbiters were used to collect the observations.

Longitude

This is the approximate longitude on the planet Mars of the image center. All values are based on the IAU 2000 aerocentric model of Mars with east positive longitude. (gives in degrees of East Longitude)

Latitude

This is the approximate latitude on the planet Mars of the image center. All values are based on the IAU 2000 aerocentric model of Mars with east positive longitude.

Orbit

Spacecraft orbit during which an observation was made.

Mission Phase

The Viking orbiter missions were both divided into the following phases:

Pre-Orbital Science Launch - Mars Orbit Insertion

Primary Mission Mars Orbit Insertion - November 1976

Extended Mission November 1976 - May 1978

Continuation Mission May 1978 - July 1979

Survey Mision July 1979 - July 1980 (Viking 1 only)

Instrument

The VIS subsystem consisted of two identical cameras: A & B.

Filters

The VIS cameras took images using the following filters:

Blue 0.35µm - 0.53µm

Minus-Blue 0.48µm - 0.70µm

Violet 0.35µm - 0.47µm

Clear 0.35µm - 0.70µm

Green 0.50µm - 0.60µm

Red 0.55µm - 0.70µm

Sample Resolution

Line Resolution

Local Solar Time'

This is the local time on Mars at the center of the image relative to a division of the martian day into 24 equal parts. A martian day is slightly longer than 24 hours and 37 minutes long.

Solar Longitude

This is the position of Mars relative to the Sun measured in degrees from the vernal equinox (start of northern Spring). This number is used as a measure of Martian seasons. (Also known as heliocentric longitude and abbreviated Ls.)

a) Northern Spring/Southern Autumn start at 0°

b) Northern Summer/Southern Winter start at 90°

c) Northern Autumn/Southern Spring start at 180°

d) Northern Winter/Southern Summer begin at 270°

Phase Angle

This is the angle between the sun, the surface, and the Viking orbiter at the time the picture was obtained.

Solar Incidence Angle

Derived for the center of the image, this is the angle between the Sun and a "normal" drawn perpendicular to the planet's surface at the time the image was acquired. A higher incidence angle means that a person standing on the ground would see the sun lower toward the horizon.

Emission Angle

Measured from the center of the image, this is the angle between the Viking orbiter and a "normal" drawn perpendicular to the planet's surface.

North Azimuth Angle

The angle between the right edge of the image and north. (Ex: 0=Image Perpendicular to Longitude Lines, 90=Image Parallel to Longitude Lines)

Slant Distance

This number is similar to the spacecraft altitude, but also takes into account the emission angle. If the emission angle is 0 then this number is the same as the spacecraft altitude. If the emission angle is much greater than 0, then the "slant distance" to the surface at the center of the image is also greater than the spacecraft altitude.

Notes

A short description or miscellaneous information about the image.

[edit] Stamp Layer Functions

The Viking Camera Stamp Layer's functions are identical to the functions of the Thermal Emission Image System (THEMIS) Stamp Layer and are explained in detail on its wiki page.